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Checking references for intended status: Experimental ---------------------------------------------------------------------------- ** Obsolete normative reference: RFC 2518 (Obsoleted by RFC 4918) ** Obsolete normative reference: RFC 2616 (Obsoleted by RFC 7230, RFC 7231, RFC 7232, RFC 7233, RFC 7234, RFC 7235) ** Obsolete normative reference: RFC 3023 (Obsoleted by RFC 7303) ** Obsolete normative reference: RFC 4234 (Obsoleted by RFC 5234) == Outdated reference: A later version (-27) exists of draft-ietf-webdav-bind-17 -- No information found for draft-dasl-requirements - is the name correct? Summary: 5 errors (**), 0 flaws (~~), 3 warnings (==), 8 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group J. Reschke, Ed. 3 Internet-Draft greenbytes 4 Intended status: Experimental S. Reddy 5 Expires: August 13, 2007 Optena 6 J. Davis 8 A. Babich 9 Filenet 10 February 9, 2007 12 Web Distributed Authoring and Versioning (WebDAV) SEARCH 13 draft-reschke-webdav-search-11 15 Status of this Memo 17 By submitting this Internet-Draft, each author represents that any 18 applicable patent or other IPR claims of which he or she is aware 19 have been or will be disclosed, and any of which he or she becomes 20 aware will be disclosed, in accordance with Section 6 of BCP 79. 22 Internet-Drafts are working documents of the Internet Engineering 23 Task Force (IETF), its areas, and its working groups. Note that 24 other groups may also distribute working documents as Internet- 25 Drafts. 27 Internet-Drafts are draft documents valid for a maximum of six months 28 and may be updated, replaced, or obsoleted by other documents at any 29 time. It is inappropriate to use Internet-Drafts as reference 30 material or to cite them other than as "work in progress." 32 The list of current Internet-Drafts can be accessed at 33 http://www.ietf.org/ietf/1id-abstracts.txt. 35 The list of Internet-Draft Shadow Directories can be accessed at 36 http://www.ietf.org/shadow.html. 38 This Internet-Draft will expire on August 13, 2007. 40 Copyright Notice 42 Copyright (C) The IETF Trust (2007). 44 Abstract 46 This document specifies a set of methods, headers, properties and 47 content-types composing WebDAV SEARCH, an application of the HTTP/1.1 48 protocol to efficiently search for DAV resources based upon a set of 49 client-supplied criteria. 51 Editorial Note (To be removed by RFC Editor before publication) 53 Please send comments to the Distributed Authoring and Versioning 54 (WebDAV) DASL mailing list at , which 55 may be joined by sending a message with subject "subscribe" to 56 . Discussions of the WebDAV 57 DASL mailing list are archived at 58 . 60 An issues list and XML and HTML versions of this draft are available 61 from . 63 Table of Contents 65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 66 1.1. DASL . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 67 1.2. Relationship to DAV . . . . . . . . . . . . . . . . . . . 5 68 1.3. Terms . . . . . . . . . . . . . . . . . . . . . . . . . . 5 69 1.4. Notational Conventions . . . . . . . . . . . . . . . . . . 7 70 1.5. Note on Usage of 'DAV:' XML Namespace . . . . . . . . . . 7 71 1.6. An Overview of DASL at Work . . . . . . . . . . . . . . . 8 72 2. The SEARCH Method . . . . . . . . . . . . . . . . . . . . . . 8 73 2.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 8 74 2.2. The Request . . . . . . . . . . . . . . . . . . . . . . . 8 75 2.2.1. The Request-URI . . . . . . . . . . . . . . . . . . . 8 76 2.2.2. The Request Body . . . . . . . . . . . . . . . . . . . 9 77 2.3. The Successful 207 (Multistatus) Response . . . . . . . . 10 78 2.3.1. Result Set Truncation . . . . . . . . . . . . . . . . 10 79 2.3.2. Extending the PROPFIND Response . . . . . . . . . . . 10 80 2.3.3. Example: A Simple Request and Response . . . . . . . . 11 81 2.3.4. Example: Result Set Truncation . . . . . . . . . . . . 12 82 2.4. Unsuccessful Responses . . . . . . . . . . . . . . . . . . 12 83 2.4.1. Example of an Invalid Scope . . . . . . . . . . . . . 13 84 3. Discovery of Supported Query Grammars . . . . . . . . . . . . 13 85 3.1. The OPTIONS Method . . . . . . . . . . . . . . . . . . . . 13 86 3.2. The DASL Response Header . . . . . . . . . . . . . . . . . 14 87 3.3. DAV:supported-query-grammar-set (protected) . . . . . . . 14 88 3.4. Example: Grammar Discovery . . . . . . . . . . . . . . . . 15 89 4. Query Schema Discovery: QSD . . . . . . . . . . . . . . . . . 17 90 4.1. Additional SEARCH Semantics . . . . . . . . . . . . . . . 17 91 4.1.1. Example of Query Schema Discovery . . . . . . . . . . 18 92 5. The DAV:basicsearch Grammar . . . . . . . . . . . . . . . . . 19 93 5.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . 19 94 5.2. The DAV:basicsearch DTD . . . . . . . . . . . . . . . . . 20 95 5.2.1. Example Query . . . . . . . . . . . . . . . . . . . . 22 97 5.3. DAV:select . . . . . . . . . . . . . . . . . . . . . . . . 23 98 5.4. DAV:from . . . . . . . . . . . . . . . . . . . . . . . . . 23 99 5.4.1. Relationship to the Request-URI . . . . . . . . . . . 23 100 5.4.2. Scope . . . . . . . . . . . . . . . . . . . . . . . . 24 101 5.5. DAV:where . . . . . . . . . . . . . . . . . . . . . . . . 24 102 5.5.1. Use of Three-Valued Logic in Queries . . . . . . . . . 24 103 5.5.2. Handling Optional Operators . . . . . . . . . . . . . 24 104 5.5.3. Treatment of NULL Values . . . . . . . . . . . . . . . 24 105 5.5.4. Treatment of Properties with mixed/element Content . . 25 106 5.5.5. Example: Testing for Equality . . . . . . . . . . . . 25 107 5.5.6. Example: Relative Comparisons . . . . . . . . . . . . 25 108 5.6. DAV:orderby . . . . . . . . . . . . . . . . . . . . . . . 26 109 5.6.1. Example of Sorting . . . . . . . . . . . . . . . . . . 26 110 5.7. Boolean Operators: DAV:and, DAV:or, and DAV:not . . . . . 26 111 5.8. DAV:eq . . . . . . . . . . . . . . . . . . . . . . . . . . 27 112 5.9. DAV:lt, DAV:lte, DAV:gt, DAV:gte . . . . . . . . . . . . . 27 113 5.10. DAV:literal . . . . . . . . . . . . . . . . . . . . . . . 27 114 5.11. DAV:typed-literal (optional) . . . . . . . . . . . . . . . 27 115 5.11.1. Example for Typed Numerical Comparison . . . . . . . . 28 116 5.12. Support for Matching xml:lang Attributes on Properties . . 28 117 5.12.1. DAV:language-defined (optional) . . . . . . . . . . . 29 118 5.12.2. DAV:language-matches (optional) . . . . . . . . . . . 29 119 5.12.3. Example of Language-Aware Matching . . . . . . . . . . 29 120 5.13. DAV:is-collection . . . . . . . . . . . . . . . . . . . . 29 121 5.13.1. Example of DAV:is-collection . . . . . . . . . . . . . 30 122 5.14. DAV:is-defined . . . . . . . . . . . . . . . . . . . . . . 30 123 5.15. DAV:like . . . . . . . . . . . . . . . . . . . . . . . . . 30 124 5.15.1. Syntax for the Literal Pattern . . . . . . . . . . . . 31 125 5.15.2. Example of DAV:like . . . . . . . . . . . . . . . . . 31 126 5.16. DAV:contains . . . . . . . . . . . . . . . . . . . . . . . 31 127 5.16.1. Result Scoring (DAV:score Element) . . . . . . . . . . 32 128 5.16.2. Ordering by Score . . . . . . . . . . . . . . . . . . 32 129 5.16.3. Examples . . . . . . . . . . . . . . . . . . . . . . . 33 130 5.17. Limiting the Result Set . . . . . . . . . . . . . . . . . 33 131 5.17.1. Relationship to Result Ordering . . . . . . . . . . . 33 132 5.18. The 'caseless' XML Attribute . . . . . . . . . . . . . . . 33 133 5.19. Query Schema for DAV:basicsearch . . . . . . . . . . . . . 34 134 5.19.1. DTD for DAV:basicsearch QSD . . . . . . . . . . . . . 34 135 5.19.2. DAV:propdesc Element . . . . . . . . . . . . . . . . . 34 136 5.19.3. The DAV:datatype Property Description . . . . . . . . 35 137 5.19.4. The DAV:searchable Property Description . . . . . . . 35 138 5.19.5. The DAV:selectable Property Description . . . . . . . 36 139 5.19.6. The DAV:sortable Property Description . . . . . . . . 36 140 5.19.7. The DAV:caseless Property Description . . . . . . . . 36 141 5.19.8. The DAV:operators XML Element . . . . . . . . . . . . 36 142 5.19.9. Example of Query Schema for DAV:basicsearch . . . . . 37 143 6. Internationalization Considerations . . . . . . . . . . . . . 37 144 7. Security Considerations . . . . . . . . . . . . . . . . . . . 38 145 7.1. Implications of XML External Entities . . . . . . . . . . 38 146 8. Scalability . . . . . . . . . . . . . . . . . . . . . . . . . 39 147 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 39 148 9.1. HTTP Headers . . . . . . . . . . . . . . . . . . . . . . . 39 149 9.1.1. DASL . . . . . . . . . . . . . . . . . . . . . . . . . 39 150 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 39 151 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 39 152 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 40 153 12.1. Normative References . . . . . . . . . . . . . . . . . . . 40 154 12.2. Informative References . . . . . . . . . . . . . . . . . . 41 155 Appendix A. Three-Valued Logic in DAV:basicsearch . . . . . . . . 42 156 Appendix B. Unresolved Issues . . . . . . . . . . . . . . . . . . 43 157 B.1. Collation Support . . . . . . . . . . . . . . . . . . . . 43 158 B.2. Count . . . . . . . . . . . . . . . . . . . . . . . . . . 44 159 B.3. Matching Media Types . . . . . . . . . . . . . . . . . . . 44 160 B.4. Query by Name . . . . . . . . . . . . . . . . . . . . . . 44 161 B.5. Result Paging . . . . . . . . . . . . . . . . . . . . . . 44 162 Appendix C. Change Log (to be removed by RFC Editor before 163 publication) . . . . . . . . . . . . . . . . . . . . 44 164 C.1. From draft-davis-dasl-protocol-xxx . . . . . . . . . . . . 45 165 C.2. since start of draft-reschke-webdav-search . . . . . . . . 46 166 C.3. since draft-reschke-webdav-search-00 . . . . . . . . . . . 48 167 C.4. since draft-reschke-webdav-search-01 . . . . . . . . . . . 48 168 C.5. since draft-reschke-webdav-search-02 . . . . . . . . . . . 49 169 C.6. since draft-reschke-webdav-search-03 . . . . . . . . . . . 49 170 C.7. since draft-reschke-webdav-search-04 . . . . . . . . . . . 49 171 C.8. since draft-reschke-webdav-search-05 . . . . . . . . . . . 50 172 C.9. since draft-reschke-webdav-search-06 . . . . . . . . . . . 51 173 C.10. since draft-reschke-webdav-search-07 . . . . . . . . . . . 51 174 C.11. since draft-reschke-webdav-search-08 . . . . . . . . . . . 51 175 C.12. since draft-reschke-webdav-search-09 . . . . . . . . . . . 52 176 C.13. since draft-reschke-webdav-search-10 . . . . . . . . . . . 52 177 Appendix D. Resolved issues (to be removed by RFC Editor 178 before publication) . . . . . . . . . . . . . . . . . 52 179 D.1. rfc2606-compliance . . . . . . . . . . . . . . . . . . . . 53 180 D.2. response-format . . . . . . . . . . . . . . . . . . . . . 53 181 D.3. result-truncation . . . . . . . . . . . . . . . . . . . . 53 182 Appendix E. Open issues (to be removed by RFC Editor prior to 183 publication) . . . . . . . . . . . . . . . . . . . . 54 184 E.1. edit . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 185 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 186 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 56 187 Intellectual Property and Copyright Statements . . . . . . . . . . 58 189 1. Introduction 191 1.1. DASL 193 This document defines Web Distributed Authoring and Versioning 194 (WebDAV) SEARCH, an application of HTTP/1.1 forming a lightweight 195 search protocol to transport queries and result sets that allows 196 clients to make use of server-side search facilities. It is based on 197 the expired draft for DAV Searching & Locating [DASL]. [DASLREQ] 198 describes the motivation for DASL. 200 DASL will minimize the complexity of clients so as to facilitate 201 widespread deployment of applications capable of utilizing the DASL 202 search mechanisms. 204 DASL consists of: 206 o the SEARCH method, 208 o the DASL response header, 210 o the DAV:searchrequest XML element, 212 o the DAV:query-schema-discovery XML element, 214 o the DAV:basicsearch XML element and query grammar, and 216 o the DAV:basicsearchschema XML element. 218 For WebDAV-compliant servers, it also defines a new live property 219 DAV:supported-query-grammar-set. 221 1.2. Relationship to DAV 223 DASL relies on the resource and property model defined by [RFC2518]. 224 DASL does not alter this model. Instead, DASL allows clients to 225 access DAV-modeled resources through server-side search. 227 1.3. Terms 229 This document uses the terms defined in [RFC2616], in [RFC2518], in 230 [RFC3253] and in this section. 232 Criteria 234 An expression against which each resource in the search scope is 235 evaluated. 237 Query 239 A query is a combination of a search scope, search criteria, 240 result record definition, sort specification, and a search 241 modifier. 243 Query Grammar 245 A set of definitions of XML elements, attributes, and constraints 246 on their relations and values that defines a set of queries and 247 the intended semantics. 249 Query Schema 251 A listing, for any given grammar and scope, of the properties and 252 operators that may be used in a query with that grammar and scope. 254 Result 256 A result is a result set, optionally augmented with other 257 information describing the search as a whole. 259 Result Record 261 A description of a resource. A result record is a set of 262 properties, and possibly other descriptive information. 264 Result Record Definition 266 A specification of the set of properties to be returned in the 267 result record. 269 Result Set 271 A set of records, one for each resource for which the search 272 criteria evaluated to True. 274 Scope 276 A set of resources to be searched. 278 Search Modifier 280 An instruction that governs the execution of the query but is not 281 part of the search scope, result record definition, the search 282 criteria, or the sort specification. An example of a search 283 modifier is one that controls how much time the server can spend 284 on the query before giving a response. 286 Sort Specification 288 A specification of an ordering on the result records in the result 289 set. 291 1.4. Notational Conventions 293 This specification uses the Augmented Backus-Naur Form (ABNF) 294 notation of [RFC4234], unless explicitly stated otherwise. 296 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 297 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 298 document are to be interpreted as described in [RFC2119]. 300 This document uses XML DTD fragments as a purely notational 301 convention. WebDAV request and response bodies can not be validated 302 due to the specific extensibility rules defined in Section 23 of 303 [RFC2518] and due to the fact that all XML elements defined by this 304 specification use the XML namespace name "DAV:". In particular: 306 1. element names use the "DAV:" namespace, 308 2. element ordering is irrelevant unless explicitly stated, 310 3. extension elements (elements not already defined as valid child 311 elements) may be added anywhere, except when explicitly stated 312 otherwise, 314 4. extension attributes (attributes not already defined as valid for 315 this element) may be added anywhere, except when explicitly 316 stated otherwise. 318 When an XML element type in the "DAV:" namespace is referenced in 319 this document outside of the context of an XML fragment, the string 320 "DAV:" will be prefixed to the element type. 322 Similarily, when an XML element type in the namespace 323 "http://www.w3.org/2001/XMLSchema" is referenced in this document 324 outside of the context of an XML fragment, the string "xs:" will be 325 prefixed to the element type. 327 1.5. Note on Usage of 'DAV:' XML Namespace 329 This spefication defines elements, properties and condition names in 330 the XML namespace "DAV:". In general, only specifications authored 331 by IETF working groups are supposed to do this. In this case an 332 exception was made, because WebDAV SEARCH started its life in the 333 IETF DASL working group (, and at the 334 time the working group closed down there was already significant 335 deployment of this specification. 337 1.6. An Overview of DASL at Work 339 One can express the basic usage of DASL in the following steps: 341 o The client constructs a query using the DAV:basicsearch grammar. 343 o The client invokes the SEARCH method on a resource that will 344 perform the search (the search arbiter) and includes a text/xml or 345 application/xml request entity that contains the query. 347 o The search arbiter performs the query. 349 o The search arbiter sends the results of the query back to the 350 client in the response. The server MUST send an entity that 351 matches the WebDAV multistatus format ([RFC2518], Section 11). 353 2. The SEARCH Method 355 2.1. Overview 357 The client invokes the SEARCH method to initiate a server-side 358 search. The body of the request defines the query. The server MUST 359 emit an entity matching the WebDAV multistatus format ([RFC2518], 360 Section 11). 362 The SEARCH method plays the role of transport mechanism for the query 363 and the result set. It does not define the semantics of the query. 364 The type of the query defines the semantics. 366 2.2. The Request 368 The client invokes the SEARCH method on the resource named by the 369 Request-URI. 371 2.2.1. The Request-URI 373 The Request-URI identifies the search arbiter. Any HTTP resource may 374 function as search arbiter. It is not a new type of resource (in the 375 sense of DAV:resourcetype as defined in Section 13.19 of [RFC2518]), 376 nor does it have to be a WebDAV-compliant resource. 378 The SEARCH method defines no relationship between the arbiter and the 379 scope of the search, rather the particular query grammar used in the 380 query defines the relationship. For example, a query grammar may 381 force the Request-URI to correspond exactly to the search scope. 383 2.2.2. The Request Body 385 The server MUST process a text/xml or application/xml request body, 386 and MAY process request bodies in other formats. See [RFC3023] for 387 guidance on packaging XML in requests. 389 Marshalling: 391 If a request body with content type text/xml or application/xml is 392 included, it MUST be either a DAV:searchrequest or a DAV:query- 393 schema-discovery XML element. Its single child element identifies 394 the query grammar. 396 For DAV:searchrequest, the definition of search criteria, the 397 result record, and any other details needed to perform the search 398 depend on the individual search grammar. 400 For DAV:query-schema-discovery, the semantics is defined in 401 Section 4. 403 Preconditions: 405 (DAV:search-grammar-discovery-supported): when an XML request body 406 is present and has a DAV:query-schema-discovery document element, 407 the server MUST support the query schema discovery mechanism 408 described in Section 4. 410 (DAV:search-grammar-supported): when an XML request body is 411 present, the search grammar identified by the document element's 412 child element must be a supported search grammar. 414 (DAV:search-multiple-scope-supported): if the SEARCH request 415 specified multiple scopes, the server MUST support this optional 416 feature. 418 (DAV:search-scope-valid): the supplied search scope must be valid. 419 There can be various reasons for a search scope to be invalid, 420 including unsupported URI schemes and communication problems. 421 Servers MAY add [RFC2518] compliant DAV:response elements as 422 content to the condition element indicating the precise reason for 423 the failure. 425 2.3. The Successful 207 (Multistatus) Response 427 If the server returns 207 (Multistatus), then the search proceeded 428 successfully and the response MUST use the WebDAV multistatus format 429 ([RFC2518], Section 11). The results of this method SHOULD NOT be 430 cached. 432 There MUST be one DAV:response for each resource that matched the 433 search criteria. For each such response, the DAV:href element 434 contains the URI of the resource, and the response MUST include a 435 DAV:propstat element. 437 Note: the WebDAV multistatus format requires at least one DAV: 438 response child element. This specification relaxes that 439 restriction so that empty results can be represented. 441 Note that for each matching resource found there may be multiple URIs 442 within the search scope mapped to it. In this case, a server SHOULD 443 report only one of these URIs. Clients can use the live property 444 DAV:resource-id defined in Section 3.1 of [BIND] to identify possible 445 duplicates. 447 2.3.1. Result Set Truncation 449 A server MAY limit the number of resources in a reply, for example to 450 limit the amount of resources expended in processing a query. If it 451 does so, the reply MUST use status code 207, return a DAV:multistatus 452 response body and indicate a status of 507 (Insufficient Storage) for 453 the search arbiter URI. It SHOULD include the partial results. 455 When a result set is truncated, there may be many more resources that 456 satisfy the search criteria but that were not examined. 458 If partial results are included and the client requested an ordered 459 result set in the original request, then any partial results that are 460 returned MUST be ordered as the client directed. 462 Note that the partial results returned MAY be any subset of the 463 result set that would have satisfied the original query. 465 2.3.2. Extending the PROPFIND Response 467 A response MAY include more information than PROPFIND defines so long 468 as the extra information does not invalidate the PROPFIND response. 469 Query grammars SHOULD define how the response matches the PROPFIND 470 response. 472 2.3.3. Example: A Simple Request and Response 474 This example demonstrates the request and response framework. The 475 following XML document shows a simple (hypothetical) natural language 476 query. The name of the query element is natural-language-query in 477 the XML namespace "http://example.com/foo". The actual query is 478 "Find the locations of good Thai restaurants in Los Angeles". For 479 this hypothetical query, the arbiter returns two properties for each 480 selected resource. 482 >> Request: 484 SEARCH / HTTP/1.1 485 Host: example.org 486 Content-Type: application/xml 487 Content-Length: xxx 489 490 491 492 Find the locations of good Thai restaurants in Los Angeles 493 494 496 >> Response: 498 HTTP/1.1 207 Multi-Status 499 Content-Type: text/xml; charset="utf-8" 500 Content-Length: xxx 502 503 505 506 http://siamiam.example/ 507 508 509 259 W. Hollywood 510 4 511 512 HTTP/1.1 200 OK 513 514 515 517 2.3.4. Example: Result Set Truncation 519 In the example below, the server returns just two results, and then 520 indicates that the result is truncated by adding a DAV:response 521 element for the search arbiter resource with 507 (Insufficient 522 Storage) status. 524 >> Request: 526 SEARCH / HTTP/1.1 527 Host: example.net 528 Content-Type: text/xml; charset="utf-8" 529 Content-Length: xxx 531 ... the query goes here ... 533 >> Response: 535 HTTP/1.1 207 Multistatus 536 Content-Type: text/xml; charset="utf-8" 537 Content-Length: xxx 539 540 541 542 http://www.example.net/sounds/unbrokenchain.au 543 HTTP/1.1 200 OK 544 545 546 http://tech.mit.example/archive96/photos/Lesh1.jpg 547 HTTP/1.1 200 OK 548 549 550 http://example.net 551 HTTP/1.1 507 Insufficient Storage 552 553 Only first two matching records were returned 554 555 556 558 2.4. Unsuccessful Responses 560 If a SEARCH request could not be executed or the attempt to execute 561 it resulted in an error, the server MUST indicate the failure with an 562 appropriate status code and SHOULD add a response body as defined in 563 [RFC3253], Section 1.6. Unless otherwise stated, condition elements 564 are empty, however specific conditions element MAY include additional 565 child elements that describe the error condition in more detail. 567 2.4.1. Example of an Invalid Scope 569 In the example below, a request failed because the scope identifies a 570 HTTP resource that was not found. 572 >> Response: 574 HTTP/1.1 409 Conflict 575 Content-Type: text/xml; charset="utf-8" 576 Content-Length: xxx 578 579 580 581 582 http://www.example.com/X 583 HTTP/1.1 404 Object Not Found 584 585 586 588 3. Discovery of Supported Query Grammars 590 Servers MUST support discovery of the query grammars supported by a 591 search arbiter resource. 593 Clients can determine which query grammars are supported by an 594 arbiter by invoking OPTIONS on the search arbiter. If the resource 595 supports SEARCH, then the DASL response header will appear in the 596 response. The DASL response header lists the supported grammars. 598 Servers supporting the WebDAV extensions [RFC3253] and/or [RFC3744] 599 MUST also 601 o report SEARCH in the live property DAV:supported-method-set for 602 all search arbiter resources and 604 o support the live property DAV:supported-query-grammar-set as 605 defined in Section 3.3. 607 3.1. The OPTIONS Method 609 The OPTIONS method allows the client to discover if a resource 610 supports the SEARCH method and to determine the list of search 611 grammars supported for that resource. 613 The client issues the OPTIONS method against a resource named by the 614 Request-URI. This is a normal invocation of OPTIONS as defined in 615 Section 9.2 of [RFC2616]. 617 If a resource supports the SEARCH method, then the server MUST list 618 SEARCH in the Allow header defined in Section 14.7 of [RFC2616]. 620 DASL servers MUST include the DASL header in the OPTIONS response. 621 This header identifies the search grammars supported by that 622 resource. 624 3.2. The DASL Response Header 626 DASLHeader = "DASL" ":" 1#Coded-URL 627 Coded-URL = 629 (This grammar uses the augmented BNF format defined in Section 2.1 of 630 [RFC2616]) 632 The DASL response header indicates server support for a query grammar 633 in the OPTIONS method. The value is a URI that indicates the type of 634 grammar. Note that although the URI can be used to identify each 635 supported search grammar, there is not necessarily a direct 636 relationship between the URI and the XML element name that can be 637 used in XML based SEARCH requests (the element name itself is 638 identified by its namespace name (a URI reference) and the element's 639 local name). 641 This header MAY be repeated. 643 For example: 645 DASL: 646 DASL: 647 DASL: 648 DASL: 650 3.3. DAV:supported-query-grammar-set (protected) 652 This WebDAV property is required for any server supporting either 653 [RFC3253] and/or [RFC3744] and identifies the XML based query 654 grammars that are supported by the search arbiter resource. 656 657 658 660 ANY value: a query grammar element type 662 3.4. Example: Grammar Discovery 664 This example shows that the server supports search on the /somefolder 665 resource with the query grammars: DAV:basicsearch, 666 http://foobar.example/syntax1 and http://akuma.example/syntax2. Note 667 that every server MUST support DAV:basicsearch. 669 >> Request: 671 OPTIONS /somefolder HTTP/1.1 672 Host: example.org 674 >> Response: 676 HTTP/1.1 200 OK 677 Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE 678 Allow: MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, SEARCH 679 DASL: 680 DASL: 681 DASL: 683 This example shows the equivalent taking advantage of a server's 684 support for DAV:supported-method-set and DAV:supported-query-grammar- 685 set. 687 >> Request: 689 PROPFIND /somefolder HTTP/1.1 690 Host: example.org 691 Depth: 0 692 Content-Type: text/xml; charset="utf-8" 693 Content-Length: xxx 695 696 697 698 699 700 701 702 >> Response: 704 HTTP/1.1 207 Multi-Status 705 Content-Type: text/xml; charset="utf-8" 706 Content-Length: xxx 708 709 710 711 http://example.org/somefolder 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 HTTP/1.1 200 OK 744 745 746 748 Note that the query grammar element names marshalled as part of the 749 DAV:supported-query-grammar-set can be directly used as element names 750 in an XML based query. 752 4. Query Schema Discovery: QSD 754 Servers MAY support the discovery of the schema for a query grammar. 756 The DASL response header and the DAV:supported-query-grammar-set 757 property provide means for clients to discover the set of query 758 grammars supported by a resource. This alone is not sufficient 759 information for a client to generate a query. For example, the DAV: 760 basicsearch grammar defines a set of queries consisting of a set of 761 operators applied to a set of properties and values, but the grammar 762 itself does not specify which properties may be used in the query. 763 QSD for the DAV:basicsearch grammar allows a client to discover the 764 set of properties that are searchable, selectable, and sortable. 765 Moreover, although the DAV:basicsearch grammar defines a minimal set 766 of operators, it is possible that a resource might support additional 767 operators in a query. For example, a resource might support a 768 optional operator that can be used to express content-based queries 769 in a proprietary syntax. QSD allows a client to discover these 770 operators and their syntax. The set of discoverable quantities will 771 differ from grammar to grammar, but each grammar can define a means 772 for a client to discover what can be discovered. 774 In general, the schema for a given query grammar depends on both the 775 resource (the arbiter) and the scope. A given resource might have 776 access to one set of properties for one potential scope, and another 777 set for a different scope. For example, consider a server able to 778 search two distinct collections, one holding cooking recipes, the 779 other design documents for nuclear weapons. While both collections 780 might support properties such as author, title, and date, the first 781 might also define properties such as calories and preparation time, 782 while the second defined properties such as yield and applicable 783 patents. Two distinct arbiters indexing the same collection might 784 also have access to different properties. For example, the recipe 785 collection mentioned above might also indexed by a value-added server 786 that also stored the names of chefs who had tested the recipe. Note 787 also that the available query schema might also depend on other 788 factors, such as the identity of the principal conducting the search, 789 but these factors are not exposed in this protocol. 791 4.1. Additional SEARCH Semantics 793 Each query grammar supported by DASL defines its own syntax for 794 expressing the possible query schema. A client retrieves the schema 795 for a given query grammar on an arbiter resource with a given scope 796 by invoking the SEARCH method on that arbiter with that grammar and 797 scope and with a root element of DAV:query-schema-discovery rather 798 than DAV:searchrequest. 800 Marshalling: 802 The request body MUST be DAV:query-schema-discovery element. 804 805 807 The response body takes the form of a RFC2518 DAV:multistatus 808 element, where DAV:response is extended to hold the returned query 809 grammar inside a DAV:query-schema container element. 811 813 815 The content of this container is an XML element whose name and syntax 816 depend upon the grammar, and whose value may (and likely will) vary 817 depending upon the grammar, arbiter, and scope. 819 4.1.1. Example of Query Schema Discovery 821 In this example, the arbiter is recipes.example, the grammar is DAV: 822 basicsearch, the scope is also recipes.example. 824 >> Request: 826 SEARCH / HTTP/1.1 827 Host: recipes.example 828 Content-Type: application/xml 829 Content-Length: xxx 831 832 833 834 835 836 http://recipes.example 837 infinity 838 839 840 841 842 >> Response: 844 HTTP/1.1 207 Multistatus 845 Content-Type: application/xml 846 Content-Length: xxx 848 849 850 851 http://recipes.example 852 HTTP/1.1 200 OK 853 854 855 857 858 859 860 862 The query schema for DAV:basicsearch is defined in Section 5.19. 864 5. The DAV:basicsearch Grammar 866 5.1. Introduction 868 DAV:basicsearch uses an extensible XML syntax that allows clients to 869 express search requests that are generally useful for WebDAV 870 scenarios. DASL-extended servers MUST accept this grammar, and MAY 871 accept other grammars. 873 DAV:basicsearch has several components: 875 o DAV:select provides the result record definition. 877 o DAV:from defines the scope. 879 o DAV:where defines the criteria. 881 o DAV:orderby defines the sort order of the result set. 883 o DAV:limit provides constraints on the query as a whole. 885 5.2. The DAV:basicsearch DTD 887 889 891 893 895 897 898 899 901 902 903 904 906 907 909 912 914 916 918 920 921 923 924 926 927 929 930 932 933 935 936 937 939 940 942 943 945 946 948 949 951 952 954 955 957 959 960 962 5.2.1. Example Query 964 This query retrieves the content length values for all resources 965 located under the server's "/container1/" URI namespace whose length 966 exceeds 10000. 968 969 970 971 972 973 974 975 /container1/ 976 infinity 977 978 979 980 981 982 10000 983 984 985 986 987 988 989 990 991 992 994 5.3. DAV:select 996 DAV:select defines the result record, which is a set of properties 997 and values. This document defines two possible values: DAV:allprop 998 and DAV:prop, both defined in [RFC2518] and revised in [RFC3253]. 1000 5.4. DAV:from 1002 1003 1005 DAV:from defines the query scope. This contains one or more DAV: 1006 scope elements. Support for multiple scope elements is optional, 1007 however servers MUST fail a request specifying multiple DAV:scope 1008 elements if they can't support it (see Section 2.2.2, precondition 1009 DAV:search-multiple-scope-supported). The scope element contains 1010 mandatory DAV:href and DAV:depth elements. 1012 DAV:href indicates the URI to use as a scope. 1014 When the scope is a collection, if DAV:depth is "0", the search 1015 includes only the collection. When it is "1", the search includes 1016 the collection and its immediate children. When it is "infinity", it 1017 includes the collection and all its progeny. 1019 When the scope is not a collection, the depth is ignored and the 1020 search applies just to the resource itself. 1022 If the search includes a redirect reference resource (see [RFC4437]), 1023 it applies only to that resource, not to its target. 1025 When the child element DAV:include-versions is present, the search 1026 scope will include all versions (see [RFC3253], Section 2.2.1) of all 1027 version-controlled resources in scope. Servers that do support 1028 versioning but do not support the DAV:include-versions feature MUST 1029 signal an error if it is used in a query. 1031 5.4.1. Relationship to the Request-URI 1033 If the DAV:scope element is an absolute URI, the scope is exactly 1034 that URI. 1036 If the DAV:scope element is is an absolute URI reference, the scope 1037 is taken to be relative to the Request-URI. 1039 5.4.2. Scope 1041 A Scope can be an arbitrary URI. 1043 Servers, of course, may support only particular scopes. This may 1044 include limitations for particular schemes such as "http:" or "ftp:" 1045 or certain URI namespaces. 1047 5.5. DAV:where 1049 The DAV:where element defines the search condition for inclusion of 1050 resources in the result set. The value of this element is an XML 1051 element that defines a search operator that evaluates to one of the 1052 Boolean truth values TRUE, FALSE, or UNKNOWN. The search operator 1053 contained by DAV:where may itself contain and evaluate additional 1054 search operators as operands, which in turn may contain and evaluate 1055 additional search operators as operands, etc. recursively. 1057 5.5.1. Use of Three-Valued Logic in Queries 1059 Each operator defined for use in the where clause that returns a 1060 Boolean value MUST evaluate to TRUE, FALSE, or UNKNOWN. The resource 1061 under scan is included as a member of the result set if and only if 1062 the search condition evaluates to TRUE. 1064 Consult Appendix A for details on the application of three-valued 1065 logic in query expressions. 1067 5.5.2. Handling Optional Operators 1069 If a query contains an operator that is not supported by the server, 1070 then the server MUST respond with a 422 (Unprocessable Entity) status 1071 code. 1073 5.5.3. Treatment of NULL Values 1075 If a PROPFIND for a property value would yield a non-2xx (see 1076 [RFC2616], Section 10.2) response for that property, then that 1077 property is considered NULL. 1079 NULL values are "less than" all other values in comparisons. 1081 Empty strings (zero length strings) are not NULL values. An empty 1082 string is "less than" a string with length greater than zero. 1084 The DAV:is-defined operator is defined to test if the value of a 1085 property is NULL. 1087 5.5.4. Treatment of Properties with mixed/element Content 1089 Comparisons of properties that do not have simple types (text-only 1090 content) is out-of-scope for the standard operators defined for DAV: 1091 basicsearch and therefore is defined to be UNKNOWN (as per 1092 Appendix A). For querying the DAV:resourcetype property, see 1093 Section 5.13. 1095 5.5.5. Example: Testing for Equality 1097 The example shows a single operator (DAV:eq) applied in the criteria. 1099 1100 1101 1102 1103 1104 100 1105 1106 1108 5.5.6. Example: Relative Comparisons 1110 The example shows a more complex operation involving several 1111 operators (DAV:and, DAV:eq, DAV:gt) applied in the criteria. This 1112 DAV:where expression matches those resources that are "image/gifs" 1113 over 4K in size. 1115 1116 1117 1118 1119 1120 1121 image/gif 1122 1123 1124 1125 1126 1127 4096 1128 1129 1130 1132 5.6. DAV:orderby 1134 The DAV:orderby element specifies the ordering of the result set. It 1135 contains one or more DAV:order elements, each of which specifies a 1136 comparison between two items in the result set. Informally, a 1137 comparison specifies a test that determines whether one resource 1138 appears before another in the result set. Comparisons are applied in 1139 the order they occur in the DAV:orderby element, earlier comparisons 1140 being more significant. 1142 The comparisons defined here use only a single property from each 1143 resource, compared using the same ordering as the DAV:lt operator 1144 (ascending) or DAV:gt operator (descending). If neither direction is 1145 specified, the default is DAV:ascending. 1147 In the context of the DAV:orderby element, null values are considered 1148 to collate before any actual (i.e., non null) value, including 1149 strings of zero length (this is compatible with [SQL99]). 1151 The "caseless" attribute may be used to indicate case-sensitivity for 1152 comparisons. 1154 5.6.1. Example of Sorting 1156 This sort orders first by last name of the author, and then by size, 1157 in descending order, so that for each author, the largest works 1158 appear first. 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1171 5.7. Boolean Operators: DAV:and, DAV:or, and DAV:not 1173 The DAV:and operator performs a logical AND operation on the 1174 expressions it contains. 1176 The DAV:or operator performs a logical OR operation on the values it 1177 contains. 1179 The DAV:not operator performs a logical NOT operation on the values 1180 it contains. 1182 5.8. DAV:eq 1184 The DAV:eq operator provides simple equality matching on property 1185 values. 1187 The "caseless" attribute may be used with this element. 1189 5.9. DAV:lt, DAV:lte, DAV:gt, DAV:gte 1191 The DAV:lt, DAV:lte, DAV:gt, and DAV:gte operators provide 1192 comparisons on property values, using less-than, less-than or equal, 1193 greater-than, and greater-than or equal respectively. The "caseless" 1194 attribute may be used with these elements. 1196 5.10. DAV:literal 1198 DAV:literal allows literal values to be placed in an expression. 1200 White space in literal values is significant in comparisons. For 1201 consistency with [RFC2518], clients SHOULD NOT specify the attribute 1202 "xml:space" (Section 2.10 of [XML]) to override this behaviour. 1204 In comparisons, the contents of DAV:literal SHOULD be treated as 1205 string, with the following exceptions: 1207 o when operand for a comparison with a DAV:getcontentlength 1208 property, it SHOULD be treated as an integer value (the behaviour 1209 for non-integer values is undefined), 1211 o when operand for a comparison with a DAV:creationdate or DAV: 1212 getlastmodified property, it SHOULD be treated as a date value in 1213 the ISO-8601 subset defined for the DAV:creationdate property 1214 ([RFC2518], Section 13.1). 1216 o when operand for a comparison with a property for which the type 1217 is known, it MAY be treated according to this type. 1219 5.11. DAV:typed-literal (optional) 1221 There are situations in which a client may want to force a comparison 1222 not to be string-based (as defined for DAV:literal). In these cases, 1223 a typed comparison can be enforced by using DAV:typed-literal 1224 instead. 1226 1227 The data type is specified using the xsi:type attribute defined in 1228 [XS1], Section 2.6.1. If the type is not specified, it defaults to 1229 "xs:string". 1231 A server MUST reject a request with an unknown type. 1233 The comparison evaluates to UNDEFINED if the property value can not 1234 be cast to the specified datatype (see [XPATHFUNC], Section 17). 1236 5.11.1. Example for Typed Numerical Comparison 1238 Consider a set of resources with the dead property "edits" in the 1239 namespace "http://ns.example.org": 1241 +-----+----------------+ 1242 | URI | property value | 1243 +-----+----------------+ 1244 | /a | "-1" | 1245 | /b | "01" | 1246 | /c | "3" | 1247 | /d | "test" | 1248 | /e | (undefined) | 1249 +-----+----------------+ 1251 The expression 1253 1256 1257 3 1258 1260 will evaluate to TRUE for the resources "/a" and "/b" (their property 1261 values can be parsed as type xs:number, and the numerical comparison 1262 evaluates to true), to FALSE for "/c" (property value is compatible, 1263 but numerical comparison evaluates to false) and UNKNOWN for "/d" and 1264 "/e" (the property either is undefined, or its value can not be 1265 parsed as xs:number). 1267 5.12. Support for Matching xml:lang Attributes on Properties 1269 The following two optional operators can be used to express 1270 conditions on the language of a property value (as expressed using 1271 the xml:lang attribute). 1273 5.12.1. DAV:language-defined (optional) 1275 1277 This operator evaluates to TRUE if the language for the value of the 1278 given property is known, FALSE if it isn't and UNKNOWN if the 1279 property itself is not defined. 1281 5.12.2. DAV:language-matches (optional) 1283 1285 This operator evaluates to TRUE if the language for the value of the 1286 given property is known and matches the language name given in the 1287 element, FALSE if it doesn't match and UNKNOWN if the 1288 property itself is not defined. 1290 Languages are considered to match if they are the same, or if the 1291 language of the property value is a sublanguage of the language 1292 specified in the element (see [XPATH], Section 4.3, "lang 1293 function"). 1295 5.12.3. Example of Language-Aware Matching 1297 The expression below will evaluate to TRUE if the property "foobar" 1298 exists and its language is either unknown, English or a sublanguage 1299 of English. 1301 1302 1303 1304 1305 1306 1307 1308 1309 en 1310 1311 1313 5.13. DAV:is-collection 1315 The DAV:is-collection operator allows clients to determine whether a 1316 resource is a collection (that is, whether its DAV:resourcetype 1317 element contains the element DAV:collection). 1319 Rationale: This operator is provided in lieu of defining generic 1320 structure queries, which would suffice for this and for many more 1321 powerful queries, but seems inappropriate to standardize at this 1322 time. 1324 5.13.1. Example of DAV:is-collection 1326 This example shows a search criterion that picks out all and only the 1327 resources in the scope that are collections. 1329 1330 1331 1333 5.14. DAV:is-defined 1335 The DAV:is-defined operator allows clients to determine whether a 1336 property is defined on a resource. The meaning of "defined on a 1337 resource" is found in Section 5.5.3. 1339 Example: 1341 1342 1343 1345 5.15. DAV:like 1347 The DAV:like is an optional operator intended to give simple 1348 wildcard-based pattern matching ability to clients. 1350 The operator takes two arguments. 1352 The first argument is a DAV:prop element identifying a single 1353 property to evaluate. 1355 The second argument is a DAV:literal element that gives the pattern 1356 matching string. 1358 5.15.1. Syntax for the Literal Pattern 1360 pattern = [wildcard] 0*( text [wildcard] ) 1362 wildcard = exactlyone / zeroormore 1363 text = 1*( character / escapeseq ) 1365 exactlyone = "_" 1366 zeroormore = "%" 1367 escapechar = "\" 1368 escapeseq = "\" ( exactlyone / zeroormore / escapechar ) 1370 ; character: see [XML], Section 2.2, minus wildcard / escapechar 1371 character = HTAB / LF / CR ; whitespace 1372 character =/ %x20-24 / %x26-5B / %x5D-5E / %x60-D7FF 1373 character =/ %xE000-FFFD / %x10000-10FFFF 1375 The value for the literal is composed of wildcards separated by 1376 segments of text. Wildcards may begin or end the literal. 1378 The "_" wildcard matches exactly one character. 1380 The "%" wildcard matches zero or more characters 1382 The "\" character is an escape sequence so that the literal can 1383 include "_" and "%". To include the "\" character in the pattern, 1384 the escape sequence "\\" is used. 1386 5.15.2. Example of DAV:like 1388 This example shows how a client might use DAV:like to identify those 1389 resources whose content type was a subtype of image. 1391 1392 1393 1394 image/% 1395 1396 1398 5.16. DAV:contains 1400 The DAV:contains operator is an optional operator that provides 1401 content-based search capability. This operator implicitly searches 1402 against the text content of a resource, not against content of 1403 properties. The DAV:contains operator is intentionally not overly 1404 constrained, in order to allow the server to do the best job it can 1405 in performing the search. 1407 The DAV:contains operator evaluates to a Boolean value. It evaluates 1408 to TRUE if the content of the resource satisfies the search. 1409 Otherwise, it evaluates to FALSE. 1411 Within the DAV:contains XML element, the client provides a phrase: a 1412 single word or whitespace delimited sequence of words. Servers MAY 1413 ignore punctuation in a phrase. Case-sensitivity is left to the 1414 server. 1416 The following things may or may not be done as part of the search: 1417 Phonetic methods such as "soundex" may or may not be used. Word 1418 stemming may or may not be performed. Thesaurus expansion of words 1419 may or may not be done. Right or left truncation may or may not be 1420 performed. The search may be case insensitive or case sensitive. 1421 The word or words may or may not be interpreted as names. Multiple 1422 words may or may not be required to be adjacent or "near" each other. 1423 Multiple words may or may not be required to occur in the same order. 1424 Multiple words may or may not be treated as a phrase. The search may 1425 or may not be interpreted as a request to find documents "similar" to 1426 the string operand. 1428 5.16.1. Result Scoring (DAV:score Element) 1430 Servers SHOULD indicate scores for the DAV:contains condition by 1431 adding a DAV:score XML element to the DAV:response element. Its 1432 value is defined only in the context of a particular query result. 1433 The value is a string representing the score, an integer from zero to 1434 10000 inclusive, where a higher value indicates a higher score (e.g. 1435 more relevant). 1437 Modified DTD fragment for DAV:propstat: 1439 1441 1443 Clients should note that, in general, it is not meaningful to compare 1444 the numeric values of scores from two different query results unless 1445 both were executed by the same underlying search system on the same 1446 collection of resources. 1448 5.16.2. Ordering by Score 1450 To order search results by their score, the DAV:score element may be 1451 added as child to the DAV:orderby element (in place of a DAV:prop 1452 element). 1454 5.16.3. Examples 1456 The example below shows a search for the phrase "Peter Forsberg". 1458 Depending on its support for content-based searching, a server MAY 1459 treat this as a search for documents that contain the words "Peter" 1460 and "Forsberg". 1462 1463 Peter Forsberg 1464 1466 The example below shows a search for resources that contain "Peter" 1467 and "Forsberg". 1469 1470 1471 Peter 1472 Forsberg 1473 1474 1476 5.17. Limiting the Result Set 1478 1479 ;only digits 1481 The DAV:limit XML element contains requested limits from the client 1482 to limit the size of the reply or amount of effort expended by the 1483 server. The DAV:nresults XML element contains a requested maximum 1484 number of DAV:response elements to be returned in the response body. 1485 The server MAY disregard this limit. The value of this element is an 1486 integer. 1488 5.17.1. Relationship to Result Ordering 1490 If the result set is both limited by DAV:limit and ordered according 1491 to DAV:orderby, the results that are included in the response 1492 document must be those that order highest. 1494 5.18. The 'caseless' XML Attribute 1496 The "caseless" attribute allows clients to specify caseless matching 1497 behaviour instead of character-by-character matching for DAV: 1498 basicsearch operators. 1500 The possible values for "caseless" are "yes" or "no". The default 1501 value is server-specified. Caseless matching SHOULD be implemented 1502 as defined in section 5.18 of the Unicode Standard ([UNICODE4]). 1504 Support for the "caseless" attribute is optional. A server should 1505 respond with a status of 422 if it is used but cannot be supported. 1507 5.19. Query Schema for DAV:basicsearch 1509 The DAV:basicsearch grammar defines a search criteria that is a 1510 Boolean-valued expression, and allows for an arbitrary set of 1511 properties to be included in the result record. The result set may 1512 be sorted on a set of property values. Accordingly the DTD for 1513 schema discovery for this grammar allows the server to express: 1515 1. the set of properties that may be either searched, returned, or 1516 used to sort, and a hint about the data type of such properties 1518 2. the set of optional operators defined by the resource. 1520 5.19.1. DTD for DAV:basicsearch QSD 1522 1523 1524 1525 1528 1529 1530 1531 1532 1534 The DAV:properties element holds a list of descriptions of 1535 properties. 1537 The DAV:operators element describes the optional operators that may 1538 be used in a DAV:where element. 1540 5.19.2. DAV:propdesc Element 1542 Each instance of a DAV:propdesc element describes the property or 1543 properties in the DAV:prop element it contains. All subsequent 1544 elements are descriptions that apply to those properties. All 1545 descriptions are optional and may appear in any order. Servers 1546 SHOULD support all the descriptions defined here, and MAY define 1547 others. 1549 DASL defines five descriptions. The first, DAV:datatype, provides a 1550 hint about the type of the property value, and may be useful to a 1551 user interface prompting for a value. The remaining four (DAV: 1552 searchable, DAV:selectable, DAV:sortable, and DAV:caseless) identify 1553 portions of the query (DAV:where, DAV:select, and DAV:orderby, 1554 respectively). If a property has a description for a section, then 1555 the server MUST allow the property to be used in that section. These 1556 descriptions are optional. If a property does not have such a 1557 description, or is not described at all, then the server MAY still 1558 allow the property to be used in the corresponding section. 1560 5.19.2.1. DAV:any-other-property 1562 This element can be used in place of DAV:prop to describe properties 1563 of WebDAV properties not mentioned in any other DAV:prop element. 1564 For instance, this can be used to indicate that all other properties 1565 are searchable and selectable without giving details about their 1566 types (a typical scenario for dead properties). 1568 5.19.3. The DAV:datatype Property Description 1570 The DAV:datatype element contains a single XML element that provides 1571 a hint about the domain of the property, which may be useful to a 1572 user interface prompting for a value to be used in a query. 1573 Datatypes are identified by an element name. Where appropriate, a 1574 server SHOULD use the simple datatypes defined in [XS2]. 1576 1578 Examples from [XS2], Section 3: 1580 +----------------+---------------------+ 1581 | Qualified name | Example | 1582 +----------------+---------------------+ 1583 | xs:boolean | true, false, 1, 0 | 1584 | xs:string | Foobar | 1585 | xs:dateTime | 1994-11-05T08:15:5Z | 1586 | xs:float | .314159265358979E+1 | 1587 | xs:integer | -259, 23 | 1588 +----------------+---------------------+ 1590 If the data type of a property is not given, then the data type 1591 defaults to xs:string. 1593 5.19.4. The DAV:searchable Property Description 1595 1597 If this element is present, then the server MUST allow this property 1598 to appear within a DAV:where element where an operator allows a 1599 property. Allowing a search does not mean that the property is 1600 guaranteed to be defined on every resource in the scope, it only 1601 indicates the server's willingness to check. 1603 5.19.5. The DAV:selectable Property Description 1605 1607 This element indicates that the property may appear in the DAV:select 1608 element. 1610 5.19.6. The DAV:sortable Property Description 1612 This element indicates that the property may appear in the DAV: 1613 orderby element. 1615 1617 5.19.7. The DAV:caseless Property Description 1619 This element only applies to properties whose data type is "xs: 1620 string" and derived data types as per the DAV:datatype property 1621 description. Its presence indicates that compares performed for 1622 searches, and the comparisons for ordering results on the string 1623 property will be caseless (the default is character-by-character). 1625 1627 5.19.8. The DAV:operators XML Element 1629 The DAV:operators element describes every optional operator supported 1630 in a query. (Mandatory operators are not listed since they are 1631 mandatory and permit no variation in syntax.). All optional 1632 operators that are supported MUST be listed in the DAV:operators 1633 element. The listing for an operator consists of the operator (as an 1634 empty element), followed by one element for each operand. The 1635 operand MUST be either DAV:operand-property, DAV:operand-literal or 1636 DAV:operand-typed-literal, which indicate that the operand in the 1637 corresponding position is a property, a literal value or a typed 1638 literal value, respectively. If an operator is polymorphic (allows 1639 more than one operand syntax) then each permitted syntax MUST be 1640 listed separately. 1642 1643 1644 1645 1647 1649 5.19.9. Example of Query Schema for DAV:basicsearch 1651 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1679 This response lists four properties. The datatype of the last three 1680 properties is not given, so it defaults to xs:string. All are 1681 selectable, and the first three may be searched. All but the last 1682 may be used in a sort. Of the optional DAV operators, DAV:is-defined 1683 and DAV:like are supported. 1685 Note: The schema discovery defined here does not provide for 1686 discovery of supported values of the "caseless" attribute. This may 1687 require that the reply also list the mandatory operators. 1689 6. Internationalization Considerations 1691 Properties may be language-tagged using the xml:lang attribute (see 1692 [RFC2518], Section 4.4). The optional operators DAV:language-defined 1693 (Section 5.12.1) and DAV:language-matches (Section 5.12.2) allow to 1694 express conditions on the language tagging information. 1696 7. Security Considerations 1698 This section is provided to detail issues concerning security 1699 implications of which DASL applications need to be aware. All of the 1700 security considerations of HTTP/1.1 also apply to DASL. In addition, 1701 this section will include security risks inherent in searching and 1702 retrieval of resource properties and content. 1704 A query must not allow one to retrieve information about values or 1705 existence of properties that one could not obtain via PROPFIND. (e.g. 1706 by use in DAV:orderby, or in expressions on properties.) 1708 A server should prepare for denial of service attacks. For example a 1709 client may issue a query for which the result set is expensive to 1710 calculate or transmit because many resources match or must be 1711 evaluated. 1713 7.1. Implications of XML External Entities 1715 XML supports a facility known as "external entities", defined in 1716 Section 4.2.2 of [XML], which instruct an XML processor to retrieve 1717 and perform an inline include of XML located at a particular URI. An 1718 external XML entity can be used to append or modify the document type 1719 declaration (DTD) associated with an XML document. An external XML 1720 entity can also be used to include XML within the content of an XML 1721 document. For non-validating XML, such as the XML used in this 1722 specification, including an external XML entity is not required by 1723 [XML]. However, [XML] does state that an XML processor may, at its 1724 discretion, include the external XML entity. 1726 External XML entities have no inherent trustworthiness and are 1727 subject to all the attacks that are endemic to any HTTP GET request. 1728 Furthermore, it is possible for an external XML entity to modify the 1729 DTD, and hence affect the final form of an XML document, in the worst 1730 case significantly modifying its semantics, or exposing the XML 1731 processor to the security risks discussed in [RFC3023]. Therefore, 1732 implementers must be aware that external XML entities should be 1733 treated as untrustworthy. 1735 There is also the scalability risk that would accompany a widely 1736 deployed application which made use of external XML entities. In 1737 this situation, it is possible that there would be significant 1738 numbers of requests for one external XML entity, potentially 1739 overloading any server which fields requests for the resource 1740 containing the external XML entity. 1742 8. Scalability 1744 Query grammars are identified by URIs. Applications SHOULD not 1745 attempt to retrieve these URIs even if they appear to be retrievable 1746 (for example, those that begin with "http://") 1748 9. IANA Considerations 1750 This document uses the namespace defined in Section 18 of [RFC2518] 1751 for XML elements. 1753 9.1. HTTP Headers 1755 This document specifies the HTTP header listed below, to be added to 1756 the HTTP header registry defined in [RFC3864]. 1758 9.1.1. DASL 1760 Header field name: DASL 1762 Applicable protocol: http 1764 Status: Experimental 1766 Author/Change controller: IETF 1768 Specification document: this specification (Section 3.2) 1770 10. Contributors 1772 This document is based on prior work on the DASL protocol done by the 1773 WebDAV DASL working group until the year 2000 -- namely by Alan 1774 Babich, Jim Davis, Rick Henderson, Dale Lowry, Saveen Reddy and 1775 Surendra Reddy. 1777 11. Acknowledgements 1779 This document has benefited from thoughtful discussion by Lisa 1780 Dusseault, Sung Kim, Elias Sinderson, Martin Wallmer, Keith 1781 Wannamaker, Jim Whitehead and Kevin Wiggen. 1783 12. References 1784 12.1. Normative References 1786 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1787 Requirement Levels", BCP 14, RFC 2119, March 1997. 1789 [RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D. 1790 Jensen, "HTTP Extensions for Distributed Authoring -- 1791 WEBDAV", RFC 2518, February 1999. 1793 [RFC2616] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., 1794 Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext 1795 Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. 1797 [RFC3023] Makoto, M., St.Laurent, S., and D. Kohn, "XML Media 1798 Types", RFC 3023, January 2001. 1800 [RFC3253] Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J. 1801 Whitehead, "Versioning Extensions to WebDAV", RFC 3253, 1802 March 2002. 1804 [RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web 1805 Distributed Authoring and Versioning (WebDAV) Access 1806 Control Protocol", RFC 3744, May 2004. 1808 [RFC4234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax 1809 Specifications: ABNF", RFC 4234, October 2005. 1811 [RFC4437] Whitehead, J., Clemm, G., and J. Reschke, Ed., "Web 1812 Distributed Authoring and Versioning (WebDAV) 1813 Redirect Reference Resources", RFC 4437, March 2006. 1815 [XML] Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E., and 1816 F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fourth 1817 Edition)", W3C REC-xml-20060816, August 2006, 1818 . 1820 [XPATH] Clark, J. and S. DeRose, "XML Path Language (XPath) 1821 Version 1.0", W3C REC-xpath-19991116, November 1999, 1822 . 1824 [XPATHFUNC] 1825 Malhotra, A., Melton, J., and N. Walsh, "XQuery 1.0 and 1826 XPath 2.0 Functions and Operators", W3C REC-xpath- 1827 functions-20070123, January 2007, 1828 . 1830 [XS1] Thompson, H., Beech, D., Maloney, M., Mendelsohn, N., and 1831 World Wide Web Consortium, "XML Schema Part 1: 1833 Structures", W3C REC-xmlschema-1-20041028, October 2004, 1834 . 1836 [XS2] Biron, P., Malhotra, A., and World Wide Web Consortium, 1837 "XML Schema Part 2: Datatypes Second Edition", W3C REC- 1838 xmlschema-2-20041028, October 2004, 1839 . 1841 12.2. Informative References 1843 [BIND] Clemm, G., Crawford, J., Reschke, J., Ed., and J. 1844 Whitehead, "Binding Extensions to WebDAV", 1845 draft-ietf-webdav-bind-17 (work in progress), 1846 February 2007. 1848 [DASL] Reddy, S., Lowry, D., Reddy, S., Henderson, R., Davis, J., 1849 and A. Babich, "DAV Searching & Locating", 1850 draft-ietf-dasl-protocol-00 (work in progress), July 1999. 1852 [DASLREQ] Davis, J., Reddy, S., and J. Slein, "Requirements for DAV 1853 Searching and Locating", February 1999, . 1857 This is an updated version of the Internet Draft 1858 "draft-ietf-dasl-requirements-00", but obviously never was 1859 submitted to the IETF. 1861 [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration 1862 Procedures for Message Header Fields", BCP 90, RFC 3864, 1863 September 2004. 1865 [SQL99] Milton, J., "Database Language SQL Part 2: Foundation 1866 (SQL/Foundation)", ISO ISO/IEC 9075-2:1999 (E), July 1999. 1868 [UNICODE4] 1869 The Unicode Consortium, "The Unicode Standard - Version 1870 4.0", Addison-Wesley , August 2003, 1871 . 1873 ISBN 0321185781 [1] 1875 URIs 1877 [1] 1879 Appendix A. Three-Valued Logic in DAV:basicsearch 1881 ANSI standard three valued logic is used when evaluating the search 1882 condition (as defined in the ANSI standard SQL specifications, for 1883 example in ANSI X3.135-1992, section 8.12, pp. 188-189, section 8.2, 1884 p. 169, General Rule 1)a), etc.). 1886 ANSI standard three valued logic is undoubtedly the most widely 1887 practiced method of dealing with the issues of properties in the 1888 search condition not having a value (e.g., being null or not defined) 1889 for the resource under scan, and with undefined expressions in the 1890 search condition (e.g., division by zero, etc.). Three valued logic 1891 works as follows. 1893 Undefined expressions are expressions for which the value of the 1894 expression is not defined. Undefined expressions are a completely 1895 separate concept from the truth value UNKNOWN, which is, in fact, 1896 well defined. Property names and literal constants are considered 1897 expressions for purposes of this section. If a property in the 1898 current resource under scan has not been set to a value, then the 1899 value of that property is undefined for the resource under scan. 1900 DASL 1.0 has no arithmetic division operator, but if it did, division 1901 by zero would be an undefined arithmetic expression. 1903 If any subpart of an arithmetic, string, or datetime subexpression is 1904 undefined, the whole arithmetic, string, or datetime subexpression is 1905 undefined. 1907 There are no manifest constants to explicitly represent undefined 1908 number, string, or datetime values. 1910 Since a Boolean value is ultimately returned by the search condition, 1911 arithmetic, string, and datetime expressions are always arguments to 1912 other operators. Examples of operators that convert arithmetic, 1913 string, and datetime expressions to Boolean values are the six 1914 relational operators ("greater than", "less than", "equals", etc.). 1915 If either or both operands of a relational operator have undefined 1916 values, then the relational operator evaluates to UNKNOWN. 1917 Otherwise, the relational operator evaluates to TRUE or FALSE, 1918 depending upon the outcome of the comparison. 1920 The Boolean operators DAV:and, DAV:or and DAV:not are evaluated 1921 according to the following rules: 1923 not UNKNOWN = UNKNOWN 1925 UNKNOWN and TRUE = UNKNOWN 1926 UNKNOWN and FALSE = FALSE 1928 UNKNOWN and UNKNOWN = UNKNOWN 1930 UNKNOWN or TRUE = TRUE 1932 UNKNOWN or FALSE = UNKNOWN 1934 UNKNOWN or UNKNOWN = UNKNOWN 1936 Appendix B. Unresolved Issues 1938 This Section summarizes issues which have been raised during the 1939 development of this specification, but for which no resolution could 1940 be found with the constraints in place. At the time of this writing, 1941 not resolving these issues and publishing as "Experimental" seemed to 1942 make more sense than not publishing at all. Future revisions of this 1943 specification should revisit these issues, though. 1945 B.1. Collation Support 1947 Matching and sorting of textual data relies on collations. With 1948 respect to WebDAV SEARCH, a combination of various design approaches 1949 could be used: 1951 o Require server support for specific collations. 1953 o Require that the server can advertise which collations it 1954 supports. 1956 o Allow a client to select the collation to be used. 1958 In practice, the current implementations of WebDAV SEARCH usually 1959 rely on backends they do not control, and for which collation 1960 information may not be available. To make things worse, 1961 implementations of the DAV:basicsearch grammar frequently need to 1962 combine data from multiple underlying stores (such as properties and 1963 full text content), and thus collation support may vary based on the 1964 operator or property. 1966 Another open issue is what collation formalism to support. At the 1967 time of this writing, the two specifications below seem to provide 1968 the necessary framework and thus may be the base for future work on 1969 collation support in WebDAV SEARCH: 1971 1. "Internet Application Protocol Collation Registry" (). 1975 2. "XQuery 1.0 and XPath 2.0 Functions and Operators" 1976 (). 1978 B.2. Count 1980 DAV:basicsearch does not allow a request that returns the count of 1981 matching resources. 1983 A protocol extension would need to extend DAV:select, and also modify 1984 the DAV:multistatus response format. 1986 B.3. Matching Media Types 1988 Matching media types using the DAV:getcontenttype property and the 1989 DAV:like operator is hard due to DAV:getcontenttype also allowing 1990 parameters. A new operator specifically designed for the purpose of 1991 matching media types probably would simplify things a lot. See 1993 for a specific proposal. 1995 B.4. Query by Name 1997 DAV:basicsearch operates on the properties (and optionally the 1998 contents) of resources, and thus doesn't really allow matching on 1999 parts of the resource's URI. See for a proposed extension 2001 covering this use case. 2003 B.5. Result Paging 2005 A frequently discussed feature is the ability to specifically request 2006 the "next" set of results, when either the server decided to truncate 2007 the result, or the client explicitly asked for a limited set (for 2008 instace, using the DAV:limit element defined in Section 5.17). 2010 In this case, it would be desirable if the server could keep the full 2011 query result, and provide a new URI identifying a separate result 2012 resource, allowing the client to retrieve additional data through GET 2013 requests, and remove the result through a DELETE request. 2015 Appendix C. Change Log (to be removed by RFC Editor before publication) 2016 C.1. From draft-davis-dasl-protocol-xxx 2018 Feb 14, 1998 Initial Draft 2020 Feb 28, 1998 Referring to DASL as an extension to HTTP/1.1 rather 2021 than DAV. 2022 Added new sections "Notational Conventions", "Protocol Model", 2023 "Security Considerations". 2024 Changed section 3 to "Elements of Protocol". 2025 Added some stuff to introduction. 2026 Added "result set" terminology. 2027 Added "IANA Considerations". 2029 Mar 9, 1998 Moved sub-headings of "Elements of Protocol" to first 2030 level and removed "Elements of Protocol" Heading. 2031 Added an sentence in introduction explaining that this is a 2032 "sketch" of a protocol. 2034 Mar 11, 1998 Added orderby, data typing, three valued logic, query 2035 schema property, and element definitions for schema for 2036 basicsearch. 2038 April 8, 1998 - made changes based on last week's DASL BOF. 2040 May 8, 1998 Removed most of DAV:searcherror; converted to DAV: 2041 searchredirect 2042 Altered DAV:basicsearch grammar to use avoid use of ANY in DTD 2044 June 17, 1998 -Added details on Query Schema Discovery 2045 -Shortened list of data types 2047 June 23, 1998 moved data types before change history 2048 rewrote the data types section 2049 removed the casesensitive element and replace with the 2050 casesensitive attribute 2051 added the casesensitive attribute to the DTD for all operations 2052 that might work on a string 2054 Jul 20, 1998 A series of changes. See Author's meeting minutes for 2055 details. 2057 July 28, 1998 Changes as per author's meeting. QSD uses SEARCH, not 2058 PROPFIND. 2059 Moved text around to keep concepts nearby. 2060 Boolean literals are 1 and 0, not T and F. 2061 contains changed to contentspassthrough. 2062 Renamed rank to score. 2064 July 28, 1998 Added Dale Lowry as Author 2066 September 4, 1998 Added 422 as response when query lists 2067 unimplemented operators. 2068 DAV:literal declares a default value for xml:space, 'preserve' 2069 (see XML spec, section 2.10) 2070 moved to new XML namespace syntax 2072 September 22, 1998 Changed "simplesearch" to "basicsearch" 2073 Changed isnull to isdefined 2074 Defined NULLness as having a 404 or 403 response 2075 used ENTITY syntax in DTD 2076 Added redirect 2078 October 9, 1998 Fixed a series of typographical and formatting 2079 errors. 2080 Modified the section of three-valued logic to use a table rather 2081 than a text description of the role of UNKNOWN in expressions. 2083 November 2, 1998 Added the DAV:contains operator. 2084 Removed the DAV:contentpassthrough operator. 2086 November 18, 1998 Various author comments for submission 2088 June 3, 1999 Cosmetic and minor editorial changes only. Fix nits 2089 reported by Jim Whitehead in email of April 26, 1999. Converted 2090 to HTML from Word 97, manually. 2092 April 20, 2000 Removed redirection feature, since 301/302 suffices. 2093 Removed Query Schema Discovery (former chapter 4). Everyone 2094 agrees this is a useful feature, but it is apparently too 2095 difficult to define at this time, and it is not essential for 2096 DASL. 2098 C.2. since start of draft-reschke-webdav-search 2100 October 09, 2001 Added Julian Reschke as author. 2101 Chapter about QSD re-added. 2102 Formatted into RFC2629-compliant XML document. 2103 Added first comments. 2104 ID version number kicked up to draft-dasl-protocol-03. 2106 October 17, 2001 Updated address information for Jim Davis. 2107 Added issue of datatype vocabularies. 2108 Updated issue descriptions for grammar discovery, added issues on 2109 query schema DTD. 2110 Fixed typos in XML examples. 2112 December 17, 2001 Re-introduced split between normative and non- 2113 normative references. 2115 January 05, 2002 Version bumped up to 04. Started work on resolving 2116 the issues identified in the previous version. 2118 January 14, 2002 Fixed some XML typos. 2120 January 22, 2002 Closed issues naming-of-elements. Fixed query 2121 search DTD and added option to discover properties of "other" 2122 (non-listed) properties. 2124 January 25, 2002 Changed into private submission and added reference 2125 to historic DASL draft. Marked reference to DASL requirements 2126 non-normative. 2127 Updated reference to latest deltav spec. 2129 January 29, 2002 Added feedback from and updated contact info for 2130 Alan Babich. 2131 Included open issues collected in 2132 http://www.webdav.org/dasl/protocol/issues.html. 2134 February 8, 2002 Made sure that all artwork fits into 72 characters 2135 wide text. 2137 February 18, 2002 Changed Insufficient storage handling 2138 (multistatus). Moved is-collection to operators and added to DTD. 2139 Made scope/depth mandatory. 2141 February 20, 2002 Updated reference to SQL99. 2143 February 28, 2002 "Non-normative References" -> "Informative 2144 References". Abstract updated. Consistently specify a charset 2145 when using text/xml (no change bars). Do not attempt to define 2146 PROPFIND's entity encoding (take out specific references to text/ 2147 xml). Remove irrelevant headers (Connection:) from examples (no 2148 change bars). Added issue on querying based on DAV:href. Updated 2149 introduction to indicate relationship to DASL draft. Updated HTTP 2150 reference from RFC2068 to RFC2616. Updated XML reference to XML 2151 1.0 2nd edition. 2153 March 1, 2002 Removed superfluous namespace decl in 2.4.2. Reopened 2154 JW14 and suggest to drop xml:space support. 2156 March 3, 2002 Removed "xml:space" feature on DAV:literal. Added 2157 issue about string comparison vs. collations vs. xml:lang. 2158 Updated some of the open issues with details from JimW's original 2159 mail in April 1999. Resolved scope vs relative URI references. 2161 Resolved issues about DAV:ascending (added to index) and the BNF 2162 for DAV:like (changed "octets" to "characters"). 2164 March 8, 2002 Updated reference to DeltaV (now RFC3253). Added 2165 Martin Wallmer's comments, moved JW5 into DAV:basicsearch section. 2167 March 11, 2002 Closed open issues regaring the type of search 2168 arbiters (JW3) and their discovery (JW9). Rephrased requirements 2169 on multistatus response bodies (propstat only if properties were 2170 selected, removed requirement for responsedescription). 2172 March 23, 2002 RFC2376 -> RFC3023. Added missing first names of 2173 authors. OPTIONS added to example for DAV:supported-method-set. 2175 C.3. since draft-reschke-webdav-search-00 2177 March 29, 2002 Abstract doesn't refer to DASL WG anymore. 2179 April 7, 2002 Fixed section title (wrong property name supported- 2180 search-grammar-set. Changed DAV:casesensitve to "casesensitive" 2181 (it wasn't in the DAV: namespace after all). 2183 May 28, 2002 Updated some issues with Jim Davis's comments. 2185 June 10, 2002 Added proposal for different method for query schema 2186 discovery, not using pseudo-properties. 2188 June 25, 2002 QSD marshalling rewritten. Added issue "isdefined- 2189 optional". 2191 C.4. since draft-reschke-webdav-search-01 2193 July 04, 2002 Added issue "scope-collection". 2195 July 08, 2002 Closed issue "scope-collection". 2197 August 12, 2002 Added issues "results-vs-binds" and "select- 2198 allprop". 2200 October 22, 2002 Added issue "undefined-expressions". 2202 November 18, 2002 Changed example host names (no change tracking). 2204 November 25, 2002 Updated issue "DB2/DB7". Closed issues "undefined 2205 expressions", "isdefined-optional" and "select-allprop". 2207 C.5. since draft-reschke-webdav-search-02 2209 November 27, 2002 Added issues "undefined-properties", "like- 2210 exactlyone" and "like-wildcard-adjacent". Closed issue "query-on- 2211 href". Added acknowledgments section. 2213 November 28, 2002 Closed issue "like-exactlyone". Added issue 2214 "mixed-content-properties". 2216 December 14, 2002 Closed issues "undefined-properties", "results-vs- 2217 binds", "mixed-content-properties". Updated issue "like-wildcard- 2218 adjacent". Added informative reference to BIND draft. Updated 2219 reference to ACL draft. 2221 January 9, 2003 Removed duplicate section on invalid scopes. Added 2222 comments to some open issues. Closed issues JW25/26, score- 2223 pseudo-property and null-ordering. 2225 January 10, 2003 Issue limit-vs-ordering plus resolution. Closed 2226 issue JW17/JW24b. 2228 January 14, 2003 New issue order-precedence. Started resolution of 2229 DB2/DB7. 2231 January 15, 2003 Started spec of DAV:typed-literal. 2233 January 17, 2003 Fix one DAV:like/DAV:getcontenttype example (add / 2234 to like expression, make case-insensitive). 2236 January 28, 2003 Update issue(s) result-truncation, JW24d. Fixed 2237 response headers in OPTIONS example. Added issue qsd-optional. 2238 Closed issue(s) order-precedence, case-insensitivity-name. 2240 February 07, 2003 Added issue scope-vs-versions. score-pseudo- 2241 property: allow DAV:orderby to explicitly specify DAV:score. 2243 C.6. since draft-reschke-webdav-search-03 2245 April 24, 2003 Fixed two "?" vs "_" issues (not updated in last 2246 draft). 2248 June 13, 2003 Improve index. 2250 C.7. since draft-reschke-webdav-search-04 2251 July 7, 2003 Typo fixed (propstat without status element). 2253 August 11, 2003 Remove superfluous IP and copyright sections. 2255 September 09, 2003 Added issues "2.4-multiple-uris" and "5.1-name- 2256 filtering". 2258 October 06, 2003 Fix misplaced section end in 5.11, add table 2259 formatting. Enhance table formatting in 5.18.3. Updated ACL and 2260 BIND references. Added XPATH reference. Closed issue JW24d by 2261 adding new optional operators. Updated more open issues, added 2262 issues from January meeting. Add K. Wiggen to Acknowledgements. 2263 Add Contributors section for the authors of the original draft. 2264 Close issue "scope-vs-versions" (optional feature added). Close 2265 (new) issue "1.3-import-DTD-terminology". Add issue "1.3-import- 2266 requirements-terminology". 2268 October 07, 2003 Typos fixed. Moved statement about DAV: namespace 2269 usage into separate (sub-)section. Closed "1.3-import- 2270 requirements-terminology". Update I18N Considerations with new 2271 xml:lang support info (see issue JW24d). Close issue "DB2/DB7" 2272 (remaining typing issues are now summarized in issue "typed- 2273 literal"). Fix misplaced section end in section 7. Started 2274 change to use RFC3253-style method definitions and error 2275 marshalling. 2277 October 08, 2003 Remove obsolete language that allowed reporting 2278 invalid scopes and such inside multistatus. Add new issue "5.4.2- 2279 scope-vs-redirects". 2281 C.8. since draft-reschke-webdav-search-05 2283 October 11, 2003 Separate DAV:basicsearch DTD into separate figures 2284 for better maintainability. Update DTD with language-* operators 2285 and typed-literal element (optional). 2287 October 14, 2003 Close issue "5.4.2-multiple-scope". 2289 November 04, 2003 Update reference from CaseMap to UNICODE4, section 2290 5.18. 2292 November 16, 2003 Updated issue "5.1-name-filtering". 2294 November 24, 2003 Reformatted scope description (collection vs. non- 2295 collection). 2297 November 30, 2003 Add issue "5_media_type_match". 2299 February 6, 2004 Updated all references. 2301 C.9. since draft-reschke-webdav-search-06 2303 July 05, 2004 Fix table in Appendix "Three-Valued Logic in DAV: 2304 basicsearch". 2306 September 14, 2004 Fix inconsistent DTD in section 5.2 and 5.4 for 2307 scope element. 2309 September 30, 2004 Rewrite editorial note and abstract. Update 2310 references (remove unneeded XMLNS, update ref to ACL and BIND 2311 specs). 2313 C.10. since draft-reschke-webdav-search-07 2315 October 01, 2004 Fix previous section heading (no change tracking). 2317 October 13, 2004 Fix DTD entry for is-collection. 2319 November 1, 2004 Fix DTD fragment query-schema-discovery. 2321 December 11, 2004 Update BIND reference. 2323 January 01, 2005 Fix DASL and DASLREQ references. 2325 February 06, 2005 Update XS2 reference. 2327 February 11, 2005 Rewrite "like" and "DASL" (response header) 2328 grammar in ABNF. 2330 May 5, 2005 Update references. Close issue "abnf" (only use ABNF 2331 when applicable). 2333 C.11. since draft-reschke-webdav-search-08 2335 May 06, 2005 Fix document title. 2337 September 25, 2005 Update BIND reference. 2339 October 05, 2005 Update RFC4234 reference. 2341 October 22, 2005 Author's address update. 2343 February 12, 2006 Update BIND reference. 2345 March 16, 2006 Add typed literals to QSD. 2347 August 20, 2006 Update XML reference. 2349 August 28, 2006 Add issues "5.3-select-count" (open) and "5.4- 2350 clarify-depth" (resolved). Update BIND reference (again). 2352 C.12. since draft-reschke-webdav-search-09 2354 December 1, 2006 Fix ABNF for DASL header. 2356 December 16, 2006 Close issue "qsd-optional", leave QSD optional. 2357 Close issue "2.4-multiple-uris", suggesting that servers should 2358 only return one response element per resource in case of multiple 2359 bindings. Add and resolve issues "authentication" and "cleanup- 2360 iana" (adding the header registration for "DASL"). Re-write 2361 rational for using the DAV: namespace, although this is a non-WG 2362 submission. 2364 January 4, 2007 Close issue "JW16b/JW24a", being related to 2365 "language-comparison". Add Appendix B. Close issues "language- 2366 comparison", "5_media_type_match", "5.1-name-filtering" and "5.3- 2367 select-count" as "won't fix", and add appendices accordingly. 2369 January 24, 2007 Update BIND reference. Close issue "5.4.2-scope- 2370 vs-redirects". Close issue "typed-literal": specify in terms of 2371 the XPATH 2.9 casting mechanism. Close issue "1.3-apply- 2372 condition-code-terminology" (no changes). 2374 C.13. since draft-reschke-webdav-search-10 2376 January 29, 2007 Issue "result-truncation": Add appendix describing 2377 the open issue of Result Paging. Describe the mechanism of 2378 marshalling truncated results in a new normative subsection (leave 2379 the actual example where it was). Add and resolve issues 2380 "rfc2606-compliance" and "response-format". Update contact 2381 information for Alan Babich, Jim Davis and Surendra Reddy (no 2382 change tracking). 2384 February 8, 2007 Update BIND reference. 2386 Appendix D. Resolved issues (to be removed by RFC Editor before 2387 publication) 2389 Issues that were either rejected or resolved in this version of this 2390 document. 2392 D.1. rfc2606-compliance 2394 Type: edit 2396 julian.reschke@greenbytes.de (2007-01-28): Make sure domain names in 2397 examples use the names allowed bc RFC2606. 2399 Resolution (2007-01-28): Done. 2401 D.2. response-format 2403 Type: edit 2405 julian.reschke@greenbytes.de (2007-01-28): Use proper RFC2518 2406 compliant DAV:response elements. 2408 Resolution (2007-01-28): Done. 2410 D.3. result-truncation 2412 Type: change 2414 2417 ldusseault@xythos.com (2002-03-29): I believe the same response body 2418 that contains the first N elements should also contain 2419 a *different* element stating that the results were incomplete and 2420 the result set was truncated by the server. There may also be a need 2421 to report that the results were incomplete and the result set was 2422 truncated at the choice of the client (isn't there a limit set in the 2423 client request?) That's important so the client knows the difference 2424 between receiving 10 results because there were >10 but only 10 were 2425 asked for, and receiving 10 results because there were only exactly 2426 10 results and it just happens that 10 were asked for. 2428 jrd3@alum.mit.edu (2002-05-28): I agree that this could be useful, 2429 but I think this issue should be consolidated with issue JW5 (see 2430 below), which proposes that DASL basicsearch ought to have a way for 2431 client to request additional result sets. It should be moved because 2432 there is little or no value in allowing a client to distinguish 2433 between the case where "N results were requested, and there are 2434 exactly N available" and "N results were requested, and there are 2435 more than N available" if there is no way for client to get the next 2436 batch of results. 2438 julian.reschke@greenbytes.de (2003-01-28): Feedback from interim WG 2439 meeting: agreement that marshalling should be rewritten and backwards 2440 compatibility is not important. Proposal: extend DAV:multistatus by 2441 a new child element that indicates (1) the range that was returned, 2442 (2) the total number of results and (3) a URI identifying the result 2443 (for resubmission when getting the "next" results). Such as 2444 ...identifier for 2445 result set... <-- number of results --> 2446 <-- 1-based index of 1st result --> <-- size 2447 of result set returned --> <-- indicates 2448 that this is a partial result --> ...response 2449 elements for search results... The example below would 2450 then translate to: HTTP/1.1 207 Multistatus Content-Type: text/xml; 2451 charset="utf-8" Content-Length: xxx 2453 2454 http://www.example.net/sounds/unbrokenchain.au 2455 HTTP/1.1 200 OK 2456 2457 http://tech.mit.test/archive96/photos/Lesh1.jpg 2458 HTTP/1.1 200 OK 2459 Q: do we need all 2460 elements, in particular start and length? 2462 julian.reschke@greenbytes.de (2003-10-07): Related: if this is 2463 supposed to be normative to DAV:basicsearch, it can't stay in an 2464 "example" sub-section. 2466 Resolution (2007-01-28): Move the explanation of Result Set 2467 Truncation into a normative section, and just leave the actual 2468 example in the "Example" subsection. Leave the reminder as-is, and 2469 not the missing result paging feature in an appendix. 2471 Appendix E. Open issues (to be removed by RFC Editor prior to 2472 publication) 2474 E.1. edit 2476 Type: edit 2478 julian.reschke@greenbytes.de (2004-07-05): Umbrella issue for 2479 editorial fixes/enhancements. 2481 Index 2483 C 2484 caseless attribute 27, 33 2485 Condition Names 2486 DAV:search-grammar-discovery-supported (pre) 9 2487 DAV:search-grammar-supported (pre) 9 2488 DAV:search-multiple-scope-supported (pre) 9 2489 DAV:search-scope-valid (pre) 9 2490 Criteria 5 2492 D 2493 DAV:and 26 2494 DAV:ascending 26 2495 DAV:contains 31 2496 DAV:depth 23 2497 DAV:descending 26 2498 DAV:eq 27 2499 caseless attribute 27 2500 DAV:from 23 2501 DAV:gt 27 2502 DAV:gte 27 2503 DAV:include-versions 23 2504 DAV:is-collection 29 2505 DAV:is-defined 30 2506 DAV:language-defined 29 2507 DAV:language-matches 29 2508 DAV:like 30 2509 DAV:limit 33 2510 DAV:literal 27 2511 DAV:lt 27 2512 DAV:lte 27 2513 DAV:not 26 2514 DAV:nresults 33 2515 DAV:or 26 2516 DAV:orderby 26 2517 DAV:scope 23 2518 DAV:score 32 2519 relationship to DAV:orderby 33 2520 DAV:search-grammar-discovery-supported precondition 9 2521 DAV:search-grammar-supported precondition 9 2522 DAV:search-multiple-scope-supported precondition 9 2523 DAV:search-scope-valid precondition 9 2524 DAV:select 23 2525 DAV:supported-query-grammar-set property 14 2526 DAV:typed-literal 27 2527 DAV:where 24 2529 M 2530 Methods 2531 SEARCH 8 2533 O 2534 OPTIONS method 13 2535 DASL response header 14 2537 P 2538 Properties 2539 DAV:supported-query-grammar-set 14 2541 Q 2542 Query Grammar Discovery 13 2543 using live property 14 2544 using OPTIONS 13 2545 Query Grammar 6 2546 Query Schema 6 2547 Query 6 2549 R 2550 Result Record Definition 6 2551 Result Record 6 2552 Result Set Truncation 2553 Example 10 2554 Result Set 6 2555 Result 6 2557 S 2558 Scope 6 2559 SEARCH method 8 2560 Search Modifier 6 2561 Sort Specification 7 2563 Authors' Addresses 2565 Julian F. Reschke (editor) 2566 greenbytes GmbH 2567 Hafenweg 16 2568 Muenster, NW 48155 2569 Germany 2571 Phone: +49 251 2807760 2572 Email: julian.reschke@greenbytes.de 2573 URI: http://greenbytes.de/tech/webdav/ 2574 Surendra Reddy 2575 Optena Corporation 2576 2860 Zanker Road, Suite 201 2577 San Jose, CA 95134 2578 U.S.A. 2580 Phone: +1 408 321 9006 2581 Email: skreddy@optena.com 2583 Jim Davis 2584 27 Borden Street 2585 Toronto, Ontario M5S 2M8 2586 Canada 2588 Phone: +1 416 929 5854 2589 Email: jrd3@alum.mit.edu 2590 URI: http://www.econetwork.net/~jdavis 2592 Alan Babich 2593 Filenet, an IBM company 2594 3565 Harbor Blvd. 2595 Costa Mesa, CA 92626 2596 U.S.A. 2598 Phone: +1 714 327 3403 2599 Email: ababich@us.ibm.com 2601 Full Copyright Statement 2603 Copyright (C) The IETF Trust (2007). 2605 This document is subject to the rights, licenses and restrictions 2606 contained in BCP 78, and except as set forth therein, the authors 2607 retain all their rights. 2609 This document and the information contained herein are provided on an 2610 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 2611 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND 2612 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS 2613 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 2614 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 2615 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 2617 Intellectual Property 2619 The IETF takes no position regarding the validity or scope of any 2620 Intellectual Property Rights or other rights that might be claimed to 2621 pertain to the implementation or use of the technology described in 2622 this document or the extent to which any license under such rights 2623 might or might not be available; nor does it represent that it has 2624 made any independent effort to identify any such rights. 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