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Checking references for intended status: Experimental ---------------------------------------------------------------------------- ** 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) -- No information found for draft-dasl-requirements - is the name correct? Summary: 4 errors (**), 0 flaws (~~), 2 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: May 18, 2008 Optena 6 J. Davis 8 A. Babich 9 Filenet 10 November 15, 2007 12 Web Distributed Authoring and Versioning (WebDAV) SEARCH 13 draft-reschke-webdav-search-14 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 May 18, 2008. 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 . . . . . . . . 9 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 . . . . . . . . 10 81 2.3.4. Example: Result Set Truncation . . . . . . . . . . . . 11 82 2.4. Unsuccessful Responses . . . . . . . . . . . . . . . . . . 12 83 2.4.1. Example of an Invalid Scope . . . . . . . . . . . . . 12 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 . . . . . . . . . . . . . . . . 14 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 C.14. since draft-reschke-webdav-search-11 . . . . . . . . . . . 52 178 C.15. since draft-reschke-webdav-search-12 . . . . . . . . . . . 53 179 C.16. since draft-reschke-webdav-search-13 . . . . . . . . . . . 53 180 Appendix D. Resolved issues (to be removed by RFC Editor 181 before publication) . . . . . . . . . . . . . . . . . 53 182 D.1. qsd-req-validity . . . . . . . . . . . . . . . . . . . . . 53 183 Appendix E. Open issues (to be removed by RFC Editor prior to 184 publication) . . . . . . . . . . . . . . . . . . . . 53 185 E.1. edit . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 186 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 187 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 55 188 Intellectual Property and Copyright Statements . . . . . . . . . . 57 190 1. Introduction 192 1.1. DASL 194 This document defines Web Distributed Authoring and Versioning 195 (WebDAV) SEARCH, an application of HTTP/1.1 forming a lightweight 196 search protocol to transport queries and result sets that allows 197 clients to make use of server-side search facilities. It is based on 198 the expired internet draft for DAV Searching & Locating [DASL]. 199 [DASLREQ] describes the motivation for DASL. In this specification, 200 the terms "WebDAV SEARCH" and "DASL" are used interchangeably. 202 DASL minimizes the complexity of clients so as to facilitate 203 widespread deployment of applications capable of utilizing the DASL 204 search mechanisms. 206 DASL consists of: 208 o the SEARCH method and the request/response formats defined for it 209 (Section 2), 211 o feature discovery through the "DASL" response header and the 212 optional DAV:supported-grammar-set property (Section 3), 214 o optional grammar schema discovery (Section 4) and 216 o one mandatory grammar: DAV:basicsearch (Section 5). 218 1.2. Relationship to DAV 220 DASL relies on the resource and property model defined by [RFC4918]. 221 DASL does not alter this model. Instead, DASL allows clients to 222 access DAV-modeled resources through server-side search. 224 1.3. Terms 226 This document uses the terms defined in [RFC2616], in [RFC4918], in 227 [RFC3253] and in this section. 229 Criteria 231 An expression against which each resource in the search scope is 232 evaluated. 234 Query 236 A query is a combination of a search scope, search criteria, 237 result record definition, sort specification, and a search 238 modifier. 240 Query Grammar 242 A set of definitions of XML elements, attributes, and constraints 243 on their relations and values that defines a set of queries and 244 the intended semantics. 246 Query Schema 248 A listing, for any given grammar and scope, of the properties and 249 operators that may be used in a query with that grammar and scope. 251 Result 253 A result is a result set, optionally augmented with other 254 information describing the search as a whole. 256 Result Record 258 A description of a resource. A result record is a set of 259 properties, and possibly other descriptive information. 261 Result Record Definition 263 A specification of the set of properties to be returned in the 264 result record. 266 Result Set 268 A set of records, one for each resource for which the search 269 criteria evaluated to True. 271 Scope 273 A set of resources to be searched. 275 Search Modifier 277 An instruction that governs the execution of the query but is not 278 part of the search scope, result record definition, the search 279 criteria, or the sort specification. An example of a search 280 modifier is one that controls how much time the server can spend 281 on the query before giving a response. 283 Sort Specification 284 A specification of an ordering on the result records in the result 285 set. 287 1.4. Notational Conventions 289 This specification uses the Augmented Backus-Naur Form (ABNF) 290 notation of [RFC4234], unless explicitly stated otherwise. 292 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 293 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 294 document are to be interpreted as described in [RFC2119]. 296 This document uses XML DTD fragments as a purely notational 297 convention. WebDAV request and response bodies can not be validated 298 due to the specific extensibility rules defined in Section 17 of 299 [RFC4918] and due to the fact that all XML elements defined by this 300 specification use the XML namespace name "DAV:". In particular: 302 1. element names use the "DAV:" namespace, 304 2. element ordering is irrelevant unless explicitly stated, 306 3. extension elements (elements not already defined as valid child 307 elements) may be added anywhere, except when explicitly stated 308 otherwise, 310 4. extension attributes (attributes not already defined as valid for 311 this element) may be added anywhere, except when explicitly 312 stated otherwise. 314 When an XML element type in the "DAV:" namespace is referenced in 315 this document outside of the context of an XML fragment, the string 316 "DAV:" will be prefixed to the element type. 318 Similarly, when an XML element type in the namespace 319 "http://www.w3.org/2001/XMLSchema" is referenced in this document 320 outside of the context of an XML fragment, the string "xs:" will be 321 prefixed to the element type. 323 1.5. Note on Usage of 'DAV:' XML Namespace 325 This specification defines elements, properties and condition names 326 in the XML namespace "DAV:". In general, only specifications 327 authored by IETF working groups are supposed to do this. In this 328 case an exception was made, because WebDAV SEARCH started its life in 329 the IETF DASL working group (, and at 330 the time the working group closed down there was already significant 331 deployment of this specification. 333 1.6. An Overview of DASL at Work 335 One can express the basic usage of DASL in the following steps: 337 o The client constructs a query using the DAV:basicsearch grammar. 339 o The client invokes the SEARCH method on a resource that will 340 perform the search (the search arbiter) and includes a text/xml or 341 application/xml request entity that contains the query. 343 o The search arbiter performs the query. 345 o The search arbiter sends the results of the query back to the 346 client in the response. The server MUST send an entity that 347 matches the WebDAV multistatus format ([RFC4918], Section 13). 349 2. The SEARCH Method 351 2.1. Overview 353 The client invokes the SEARCH method to initiate a server-side 354 search. The body of the request defines the query. The server MUST 355 emit an entity matching the WebDAV multistatus format ([RFC4918], 356 Section 13). 358 The SEARCH method plays the role of transport mechanism for the query 359 and the result set. It does not define the semantics of the query. 360 The type of the query defines the semantics. 362 2.2. The Request 364 The client invokes the SEARCH method on the resource named by the 365 Request-URI. 367 2.2.1. The Request-URI 369 The Request-URI identifies the search arbiter. Any HTTP resource may 370 function as search arbiter. It is not a new type of resource (in the 371 sense of DAV:resourcetype as defined in [RFC4918], Section 15.9), nor 372 does it have to be a WebDAV-compliant resource. 374 The SEARCH method defines no relationship between the arbiter and the 375 scope of the search, rather the particular query grammar used in the 376 query defines the relationship. For example, a query grammar may 377 force the Request-URI to correspond exactly to the search scope. 379 2.2.2. The Request Body 381 The server MUST process a text/xml or application/xml request body, 382 and MAY process request bodies in other formats. See [RFC3023] for 383 guidance on packaging XML in requests. 385 Marshalling: 387 If a request body with content type text/xml or application/xml is 388 included, it MUST be either a DAV:searchrequest or a DAV:query- 389 schema-discovery XML element. Its single child element identifies 390 the query grammar. 392 For DAV:searchrequest, the definition of search criteria, the 393 result record, and any other details needed to perform the search 394 depend on the individual search grammar. 396 For DAV:query-schema-discovery, the semantics is defined in 397 Section 4. 399 Preconditions: 401 (DAV:search-grammar-discovery-supported): when an XML request body 402 is present and has a DAV:query-schema-discovery document element, 403 the server MUST support the query schema discovery mechanism 404 described in Section 4. 406 (DAV:search-grammar-supported): when an XML request body is 407 present, the search grammar identified by the document element's 408 child element must be a supported search grammar. 410 (DAV:search-multiple-scope-supported): if the SEARCH request 411 specified multiple scopes, the server MUST support this optional 412 feature. 414 (DAV:search-scope-valid): the supplied search scope must be valid. 415 There can be various reasons for a search scope to be invalid, 416 including unsupported URI schemes and communication problems. 417 Servers MAY add [RFC4918] compliant DAV:response elements as 418 content to the condition element indicating the precise reason for 419 the failure. 421 2.3. The Successful 207 (Multistatus) Response 423 If the server returns 207 (Multistatus), then the search proceeded 424 successfully and the response MUST use the WebDAV multistatus format 425 ([RFC4918], Section 13). The results of this method SHOULD NOT be 426 cached. 428 There MUST be one DAV:response for each resource that matched the 429 search criteria. For each such response, the DAV:href element 430 contains the URI of the resource, and the response MUST include a 431 DAV:propstat element. 433 Note: the WebDAV multistatus format requires at least one DAV: 434 response child element. This specification relaxes that 435 restriction so that empty results can be represented. 437 Note that for each matching resource found there may be multiple URIs 438 within the search scope mapped to it. In this case, a server SHOULD 439 report only one of these URIs. Clients can use the live property 440 DAV:resource-id defined in Section 3.1 of [draft-ietf-webdav-bind] to 441 identify possible duplicates. 443 2.3.1. Result Set Truncation 445 A server MAY limit the number of resources in a reply, for example to 446 limit the amount of resources expended in processing a query. If it 447 does so, the reply MUST use status code 207, return a DAV:multistatus 448 response body and indicate a status of 507 (Insufficient Storage) for 449 the search arbiter URI. It SHOULD include the partial results. 451 When a result set is truncated, there may be many more resources that 452 satisfy the search criteria but that were not examined. 454 If partial results are included and the client requested an ordered 455 result set in the original request, then any partial results that are 456 returned MUST be ordered as the client directed. 458 Note that the partial results returned MAY be any subset of the 459 result set that would have satisfied the original query. 461 2.3.2. Extending the PROPFIND Response 463 A response MAY include more information than PROPFIND defines so long 464 as the extra information does not invalidate the PROPFIND response. 465 Query grammars SHOULD define how the response matches the PROPFIND 466 response. 468 2.3.3. Example: A Simple Request and Response 470 This example demonstrates the request and response framework. The 471 following XML document shows a simple (hypothetical) natural language 472 query. The name of the query element is natural-language-query in 473 the XML namespace "http://example.com/foo". The actual query is 474 "Find the locations of good Thai restaurants in Los Angeles". For 475 this hypothetical query, the arbiter returns two properties for each 476 selected resource. 478 >> Request: 480 SEARCH / HTTP/1.1 481 Host: example.org 482 Content-Type: application/xml 483 Content-Length: xxx 485 486 487 488 Find the locations of good Thai restaurants in Los Angeles 489 490 492 >> Response: 494 HTTP/1.1 207 Multi-Status 495 Content-Type: text/xml; charset="utf-8" 496 Content-Length: xxx 498 499 501 502 http://siamiam.example/ 503 504 505 259 W. Hollywood 506 4 507 508 HTTP/1.1 200 OK 509 510 511 513 2.3.4. Example: Result Set Truncation 515 In the example below, the server returns just two results, and then 516 indicates that the result is truncated by adding a DAV:response 517 element for the search arbiter resource with 507 (Insufficient 518 Storage) status. 520 >> Request: 522 SEARCH / HTTP/1.1 523 Host: example.net 524 Content-Type: text/xml; charset="utf-8" 525 Content-Length: xxx 527 ... the query goes here ... 529 >> Response: 531 HTTP/1.1 207 Multistatus 532 Content-Type: text/xml; charset="utf-8" 533 Content-Length: xxx 535 536 537 538 http://www.example.net/sounds/unbrokenchain.au 539 HTTP/1.1 200 OK 540 541 542 http://tech.mit.example/archive96/photos/Lesh1.jpg 543 HTTP/1.1 200 OK 544 545 546 http://example.net 547 HTTP/1.1 507 Insufficient Storage 548 549 Only first two matching records were returned 550 551 552 554 2.4. Unsuccessful Responses 556 If a SEARCH request could not be executed or the attempt to execute 557 it resulted in an error, the server MUST indicate the failure with an 558 appropriate status code and SHOULD add a response body as defined in 559 [RFC3253], Section 1.6. Unless otherwise stated, condition elements 560 are empty, however specific conditions element MAY include additional 561 child elements that describe the error condition in more detail. 563 2.4.1. Example of an Invalid Scope 565 In the example below, a request failed because the scope identifies a 566 HTTP resource that was not found. 568 >> Response: 570 HTTP/1.1 409 Conflict 571 Content-Type: text/xml; charset="utf-8" 572 Content-Length: xxx 574 575 576 577 578 http://www.example.com/X 579 HTTP/1.1 404 Object Not Found 580 581 582 584 3. Discovery of Supported Query Grammars 586 Servers MUST support discovery of the query grammars supported by a 587 search arbiter resource. 589 Clients can determine which query grammars are supported by an 590 arbiter by invoking OPTIONS on the search arbiter. If the resource 591 supports SEARCH, then the DASL response header will appear in the 592 response. The DASL response header lists the supported grammars. 594 Servers supporting the WebDAV extensions [RFC3253] and/or [RFC3744] 595 MUST also 597 o report SEARCH in the live property DAV:supported-method-set for 598 all search arbiter resources and 600 o support the live property DAV:supported-query-grammar-set as 601 defined in Section 3.3. 603 3.1. The OPTIONS Method 605 The OPTIONS method allows the client to discover if a resource 606 supports the SEARCH method and to determine the list of search 607 grammars supported for that resource. 609 The client issues the OPTIONS method against a resource named by the 610 Request-URI. This is a normal invocation of OPTIONS as defined in 611 Section 9.2 of [RFC2616]. 613 If a resource supports the SEARCH method, then the server MUST list 614 SEARCH in the Allow header defined in Section 14.7 of [RFC2616]. 616 DASL servers MUST include the DASL header in the OPTIONS response. 617 This header identifies the search grammars supported by that 618 resource. 620 3.2. The DASL Response Header 622 DASLHeader = "DASL" ":" 1#Coded-URL 623 Coded-URL = 625 (This grammar uses the augmented BNF format defined in Section 2.1 of 626 [RFC2616]) 628 The DASL response header indicates server support for a query grammar 629 in the OPTIONS method. The value is a URI that indicates the type of 630 grammar. Note that although the URI can be used to identify each 631 supported search grammar, there is not necessarily a direct 632 relationship between the URI and the XML element name that can be 633 used in XML based SEARCH requests (the element name itself is 634 identified by its namespace name (a URI reference) and the element's 635 local name). 637 This header MAY be repeated. 639 For example: 641 DASL: 642 DASL: 643 DASL: 644 DASL: 646 3.3. DAV:supported-query-grammar-set (protected) 648 This WebDAV property is required for any server supporting either 649 [RFC3253] and/or [RFC3744] and identifies the XML based query 650 grammars that are supported by the search arbiter resource. 652 653 654 656 ANY value: a query grammar element type 658 3.4. Example: Grammar Discovery 660 This example shows that the server supports search on the /somefolder 661 resource with the query grammars: DAV:basicsearch, 662 http://foobar.example/syntax1 and http://akuma.example/syntax2. Note 663 that every server MUST support DAV:basicsearch. 665 >> Request: 667 OPTIONS /somefolder HTTP/1.1 668 Host: example.org 670 >> Response: 672 HTTP/1.1 200 OK 673 Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE 674 Allow: MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, SEARCH 675 DASL: 676 DASL: 677 DASL: 679 This example shows the equivalent taking advantage of a server's 680 support for DAV:supported-method-set and DAV:supported-query-grammar- 681 set. 683 >> Request: 685 PROPFIND /somefolder HTTP/1.1 686 Host: example.org 687 Depth: 0 688 Content-Type: text/xml; charset="utf-8" 689 Content-Length: xxx 691 692 693 694 695 696 697 698 >> Response: 700 HTTP/1.1 207 Multi-Status 701 Content-Type: text/xml; charset="utf-8" 702 Content-Length: xxx 704 705 706 707 http://example.org/somefolder 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 HTTP/1.1 200 OK 740 741 742 744 Note that the query grammar element names marshalled as part of the 745 DAV:supported-query-grammar-set can be directly used as element names 746 in an XML based query. 748 4. Query Schema Discovery: QSD 750 Servers MAY support the discovery of the schema for a query grammar. 752 The DASL response header and the DAV:supported-query-grammar-set 753 property provide means for clients to discover the set of query 754 grammars supported by a resource. This alone is not sufficient 755 information for a client to generate a query. For example, the DAV: 756 basicsearch grammar defines a set of queries consisting of a set of 757 operators applied to a set of properties and values, but the grammar 758 itself does not specify which properties may be used in the query. 759 QSD for the DAV:basicsearch grammar allows a client to discover the 760 set of properties that are searchable, selectable, and sortable. 761 Moreover, although the DAV:basicsearch grammar defines a minimal set 762 of operators, it is possible that a resource might support additional 763 operators in a query. For example, a resource might support a 764 optional operator that can be used to express content-based queries 765 in a proprietary syntax. QSD allows a client to discover these 766 operators and their syntax. The set of discoverable quantities will 767 differ from grammar to grammar, but each grammar can define a means 768 for a client to discover what can be discovered. 770 In general, the schema for a given query grammar depends on both the 771 resource (the arbiter) and the scope. A given resource might have 772 access to one set of properties for one potential scope, and another 773 set for a different scope. For example, consider a server able to 774 search two distinct collections, one holding cooking recipes, the 775 other design documents for nuclear weapons. While both collections 776 might support properties such as author, title, and date, the first 777 might also define properties such as calories and preparation time, 778 while the second defined properties such as yield and applicable 779 patents. Two distinct arbiters indexing the same collection might 780 also have access to different properties. For example, the recipe 781 collection mentioned above might also indexed by a value-added server 782 that also stored the names of chefs who had tested the recipe. Note 783 also that the available query schema might also depend on other 784 factors, such as the identity of the principal conducting the search, 785 but these factors are not exposed in this protocol. 787 4.1. Additional SEARCH Semantics 789 Each query grammar supported by DASL defines its own syntax for 790 expressing the possible query schema. A client retrieves the schema 791 for a given query grammar on an arbiter resource with a given scope 792 by invoking the SEARCH method on that arbiter with that grammar and 793 scope and with a root element of DAV:query-schema-discovery rather 794 than DAV:searchrequest. 796 Marshalling: 798 The request body MUST be a DAV:query-schema-discovery element. 800 801 804 The response body takes the form of a DAV:multistatus element 805 ([RFC4918], Section 13), where DAV:response is extended to hold 806 the returned query grammar inside a DAV:query-schema container 807 element. 809 811 813 The content of this container is an XML element whose name and syntax 814 depend upon the grammar, and whose value may (and likely will) vary 815 depending upon the grammar, arbiter, and scope. 817 4.1.1. Example of Query Schema Discovery 819 In this example, the arbiter is recipes.example, the grammar is DAV: 820 basicsearch, the scope is also recipes.example. 822 >> Request: 824 SEARCH / HTTP/1.1 825 Host: recipes.example 826 Content-Type: application/xml 827 Content-Length: xxx 829 830 831 832 833 834 http://recipes.example 835 infinity 836 837 838 839 840 >> Response: 842 HTTP/1.1 207 Multistatus 843 Content-Type: application/xml 844 Content-Length: xxx 846 847 848 849 http://recipes.example 850 HTTP/1.1 200 OK 851 852 853 855 856 857 858 860 The query schema for DAV:basicsearch is defined in Section 5.19. 862 5. The DAV:basicsearch Grammar 864 5.1. Introduction 866 DAV:basicsearch uses an extensible XML syntax that allows clients to 867 express search requests that are generally useful for WebDAV 868 scenarios. DASL-extended servers MUST accept this grammar, and MAY 869 accept other grammars. 871 DAV:basicsearch has several components: 873 o DAV:select provides the result record definition. 875 o DAV:from defines the scope. 877 o DAV:where defines the criteria. 879 o DAV:orderby defines the sort order of the result set. 881 o DAV:limit provides constraints on the query as a whole. 883 5.2. The DAV:basicsearch DTD 885 887 889 891 893 895 896 897 899 900 901 902 904 905 907 910 912 914 916 918 919 921 922 924 925 927 928 930 931 933 934 935 937 938 940 941 943 944 946 947 949 950 952 953 955 957 958 960 5.2.1. Example Query 962 This query retrieves the content length values for all resources 963 located under the server's "/container1/" URI namespace whose length 964 exceeds 10000. 966 967 968 969 970 971 972 973 /container1/ 974 infinity 975 976 977 978 979 980 10000 981 982 983 984 985 986 987 988 989 990 992 5.3. DAV:select 994 DAV:select defines the result record, which is a set of properties 995 and values. This document defines two possible values: DAV:allprop 996 and DAV:prop, both defined in Section 14 of [RFC4918]. 998 5.4. DAV:from 1000 1001 1003 DAV:from defines the query scope. This contains one or more DAV: 1004 scope elements. Support for multiple scope elements is optional, 1005 however servers MUST fail a request specifying multiple DAV:scope 1006 elements if they can't support it (see Section 2.2.2, precondition 1007 DAV:search-multiple-scope-supported). The scope element contains 1008 mandatory DAV:href and DAV:depth elements. 1010 DAV:href indicates the URI to use as a scope. 1012 When the scope is a collection, if DAV:depth is "0", the search 1013 includes only the collection. When it is "1", the search includes 1014 the collection and its immediate children. When it is "infinity", it 1015 includes the collection and all its progeny. 1017 When the scope is not a collection, the depth is ignored and the 1018 search applies just to the resource itself. 1020 If the search includes a redirect reference resource (see [RFC4437]), 1021 it applies only to that resource, not to its target. 1023 When the child element DAV:include-versions is present, the search 1024 scope will include all versions (see [RFC3253], Section 2.2.1) of all 1025 version-controlled resources in scope. Servers that do support 1026 versioning but do not support the DAV:include-versions feature MUST 1027 signal an error if it is used in a query. 1029 5.4.1. Relationship to the Request-URI 1031 If the DAV:scope element is an absolute URI, the scope is exactly 1032 that URI. 1034 If the DAV:scope element is is an absolute URI reference, the scope 1035 is taken to be relative to the Request-URI. 1037 5.4.2. Scope 1039 A Scope can be an arbitrary URI. 1041 Servers, of course, may support only particular scopes. This may 1042 include limitations for particular schemes such as "http:" or "ftp:" 1043 or certain URI namespaces. 1045 5.5. DAV:where 1047 The DAV:where element defines the search condition for inclusion of 1048 resources in the result set. The value of this element is an XML 1049 element that defines a search operator that evaluates to one of the 1050 Boolean truth values TRUE, FALSE, or UNKNOWN. The search operator 1051 contained by DAV:where may itself contain and evaluate additional 1052 search operators as operands, which in turn may contain and evaluate 1053 additional search operators as operands, etc. recursively. 1055 5.5.1. Use of Three-Valued Logic in Queries 1057 Each operator defined for use in the where clause that returns a 1058 Boolean value MUST evaluate to TRUE, FALSE, or UNKNOWN. The resource 1059 under scan is included as a member of the result set if and only if 1060 the search condition evaluates to TRUE. 1062 Consult Appendix A for details on the application of three-valued 1063 logic in query expressions. 1065 5.5.2. Handling Optional Operators 1067 If a query contains an operator that is not supported by the server, 1068 then the server MUST respond with a 422 (Unprocessable Entity) status 1069 code. 1071 5.5.3. Treatment of NULL Values 1073 If a PROPFIND for a property value would yield a non-2xx (see 1074 [RFC2616], Section 10.2) response for that property, then that 1075 property is considered NULL. 1077 NULL values are "less than" all other values in comparisons. 1079 Empty strings (zero length strings) are not NULL values. An empty 1080 string is "less than" a string with length greater than zero. 1082 The DAV:is-defined operator is defined to test if the value of a 1083 property is NULL. 1085 5.5.4. Treatment of Properties with mixed/element Content 1087 Comparisons of properties that do not have simple types (text-only 1088 content) is out-of-scope for the standard operators defined for DAV: 1089 basicsearch and therefore is defined to be UNKNOWN (as per 1090 Appendix A). For querying the DAV:resourcetype property, see 1091 Section 5.13. 1093 5.5.5. Example: Testing for Equality 1095 The example shows a single operator (DAV:eq) applied in the criteria. 1097 1098 1099 1100 1101 1102 100 1103 1104 1106 5.5.6. Example: Relative Comparisons 1108 The example shows a more complex operation involving several 1109 operators (DAV:and, DAV:eq, DAV:gt) applied in the criteria. This 1110 DAV:where expression matches those resources that are "image/gifs" 1111 over 4K in size. 1113 1114 1115 1116 1117 1118 1119 image/gif 1120 1121 1122 1123 1124 1125 4096 1126 1127 1128 1130 5.6. DAV:orderby 1132 The DAV:orderby element specifies the ordering of the result set. It 1133 contains one or more DAV:order elements, each of which specifies a 1134 comparison between two items in the result set. Informally, a 1135 comparison specifies a test that determines whether one resource 1136 appears before another in the result set. Comparisons are applied in 1137 the order they occur in the DAV:orderby element, earlier comparisons 1138 being more significant. 1140 The comparisons defined here use only a single property from each 1141 resource, compared using the same ordering as the DAV:lt operator 1142 (ascending) or DAV:gt operator (descending). If neither direction is 1143 specified, the default is DAV:ascending. 1145 In the context of the DAV:orderby element, null values are considered 1146 to collate before any actual (i.e., non null) value, including 1147 strings of zero length (this is compatible with [SQL99]). 1149 The "caseless" attribute may be used to indicate case-sensitivity for 1150 comparisons. 1152 5.6.1. Example of Sorting 1154 This sort orders first by last name of the author, and then by size, 1155 in descending order, so that for each author, the largest works 1156 appear first. 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1169 5.7. Boolean Operators: DAV:and, DAV:or, and DAV:not 1171 The DAV:and operator performs a logical AND operation on the 1172 expressions it contains. 1174 The DAV:or operator performs a logical OR operation on the values it 1175 contains. 1177 The DAV:not operator performs a logical NOT operation on the values 1178 it contains. 1180 5.8. DAV:eq 1182 The DAV:eq operator provides simple equality matching on property 1183 values. 1185 The "caseless" attribute may be used with this element. 1187 5.9. DAV:lt, DAV:lte, DAV:gt, DAV:gte 1189 The DAV:lt, DAV:lte, DAV:gt, and DAV:gte operators provide 1190 comparisons on property values, using less-than, less-than or equal, 1191 greater-than, and greater-than or equal respectively. The "caseless" 1192 attribute may be used with these elements. 1194 5.10. DAV:literal 1196 DAV:literal allows literal values to be placed in an expression. 1198 White space in literal values is significant in comparisons. For 1199 consistency with [RFC4918], clients SHOULD NOT specify the attribute 1200 "xml:space" (Section 2.10 of [XML]) to override this behavior. 1202 In comparisons, the contents of DAV:literal SHOULD be treated as 1203 string, with the following exceptions: 1205 o when operand for a comparison with a DAV:getcontentlength 1206 property, it SHOULD be treated as an integer value (the behavior 1207 for non-integer values is undefined), 1209 o when operand for a comparison with a DAV:creationdate or DAV: 1210 getlastmodified property, it SHOULD be treated as a date value in 1211 the ISO-8601 subset defined for the DAV:creationdate property 1212 ([RFC4918], Section 15.1). 1214 o when operand for a comparison with a property for which the type 1215 is known, it MAY be treated according to this type. 1217 5.11. DAV:typed-literal (optional) 1219 There are situations in which a client may want to force a comparison 1220 not to be string-based (as defined for DAV:literal). In these cases, 1221 a typed comparison can be enforced by using DAV:typed-literal 1222 instead. 1224 1225 The data type is specified using the xsi:type attribute defined in 1226 [XS1], Section 2.6.1. If the type is not specified, it defaults to 1227 "xs:string". 1229 A server MUST reject a request with an unknown type. 1231 The comparison evaluates to UNDEFINED if the property value can not 1232 be cast to the specified datatype (see [XPATHFUNC], Section 17). 1234 5.11.1. Example for Typed Numerical Comparison 1236 Consider a set of resources with the dead property "edits" in the 1237 namespace "http://ns.example.org": 1239 +-----+----------------+ 1240 | URI | property value | 1241 +-----+----------------+ 1242 | /a | "-1" | 1243 | /b | "01" | 1244 | /c | "3" | 1245 | /d | "test" | 1246 | /e | (undefined) | 1247 +-----+----------------+ 1249 The expression 1251 1254 1255 3 1256 1258 will evaluate to TRUE for the resources "/a" and "/b" (their property 1259 values can be parsed as type xs:number, and the numerical comparison 1260 evaluates to true), to FALSE for "/c" (property value is compatible, 1261 but numerical comparison evaluates to false) and UNKNOWN for "/d" and 1262 "/e" (the property either is undefined, or its value can not be 1263 parsed as xs:number). 1265 5.12. Support for Matching xml:lang Attributes on Properties 1267 The following two optional operators can be used to express 1268 conditions on the language of a property value (as expressed using 1269 the xml:lang attribute). 1271 5.12.1. DAV:language-defined (optional) 1273 1275 This operator evaluates to TRUE if the language for the value of the 1276 given property is known, FALSE if it isn't and UNKNOWN if the 1277 property itself is not defined. 1279 5.12.2. DAV:language-matches (optional) 1281 1283 This operator evaluates to TRUE if the language for the value of the 1284 given property is known and matches the language name given in the 1285 element, FALSE if it doesn't match and UNKNOWN if the 1286 property itself is not defined. 1288 Languages are considered to match if they are the same, or if the 1289 language of the property value is a sublanguage of the language 1290 specified in the element (see [XPATH], Section 4.3, "lang 1291 function"). 1293 5.12.3. Example of Language-Aware Matching 1295 The expression below will evaluate to TRUE if the property "foobar" 1296 exists and its language is either unknown, English or a sublanguage 1297 of English. 1299 1300 1301 1302 1303 1304 1305 1306 1307 en 1308 1309 1311 5.13. DAV:is-collection 1313 The DAV:is-collection operator allows clients to determine whether a 1314 resource is a collection (that is, whether its DAV:resourcetype 1315 element contains the element DAV:collection). 1317 Rationale: This operator is provided in lieu of defining generic 1318 structure queries, which would suffice for this and for many more 1319 powerful queries, but seems inappropriate to standardize at this 1320 time. 1322 5.13.1. Example of DAV:is-collection 1324 This example shows a search criterion that picks out all and only the 1325 resources in the scope that are collections. 1327 1328 1329 1331 5.14. DAV:is-defined 1333 The DAV:is-defined operator allows clients to determine whether a 1334 property is defined on a resource. The meaning of "defined on a 1335 resource" is found in Section 5.5.3. 1337 Example: 1339 1340 1341 1343 5.15. DAV:like 1345 The DAV:like is an optional operator intended to give simple 1346 wildcard-based pattern matching ability to clients. 1348 The operator takes two arguments. 1350 The first argument is a DAV:prop element identifying a single 1351 property to evaluate. 1353 The second argument is a DAV:literal element that gives the pattern 1354 matching string. 1356 5.15.1. Syntax for the Literal Pattern 1358 pattern = [wildcard] 0*( text [wildcard] ) 1360 wildcard = exactlyone / zeroormore 1361 text = 1*( character / escapeseq ) 1363 exactlyone = "_" 1364 zeroormore = "%" 1365 escapechar = "\" 1366 escapeseq = "\" ( exactlyone / zeroormore / escapechar ) 1368 ; character: see [XML], Section 2.2, minus wildcard / escapechar 1369 character = HTAB / LF / CR ; whitespace 1370 character =/ %x20-24 / %x26-5B / %x5D-5E / %x60-D7FF 1371 character =/ %xE000-FFFD / %x10000-10FFFF 1373 The value for the literal is composed of wildcards separated by 1374 segments of text. Wildcards may begin or end the literal. 1376 The "_" wildcard matches exactly one character. 1378 The "%" wildcard matches zero or more characters 1380 The "\" character is an escape sequence so that the literal can 1381 include "_" and "%". To include the "\" character in the pattern, 1382 the escape sequence "\\" is used. 1384 5.15.2. Example of DAV:like 1386 This example shows how a client might use DAV:like to identify those 1387 resources whose content type was a subtype of image. 1389 1390 1391 1392 image/% 1393 1394 1396 5.16. DAV:contains 1398 The DAV:contains operator is an optional operator that provides 1399 content-based search capability. This operator implicitly searches 1400 against the text content of a resource, not against content of 1401 properties. The DAV:contains operator is intentionally not overly 1402 constrained, in order to allow the server to do the best job it can 1403 in performing the search. 1405 The DAV:contains operator evaluates to a Boolean value. It evaluates 1406 to TRUE if the content of the resource satisfies the search. 1407 Otherwise, it evaluates to FALSE. 1409 Within the DAV:contains XML element, the client provides a phrase: a 1410 single word or whitespace delimited sequence of words. Servers MAY 1411 ignore punctuation in a phrase. Case-sensitivity is left to the 1412 server. 1414 The following things may or may not be done as part of the search: 1415 Phonetic methods such as "soundex" may or may not be used. Word 1416 stemming may or may not be performed. Thesaurus expansion of words 1417 may or may not be done. Right or left truncation may or may not be 1418 performed. The search may be case insensitive or case sensitive. 1419 The word or words may or may not be interpreted as names. Multiple 1420 words may or may not be required to be adjacent or "near" each other. 1421 Multiple words may or may not be required to occur in the same order. 1422 Multiple words may or may not be treated as a phrase. The search may 1423 or may not be interpreted as a request to find documents "similar" to 1424 the string operand. 1426 5.16.1. Result Scoring (DAV:score Element) 1428 Servers SHOULD indicate scores for the DAV:contains condition by 1429 adding a DAV:score XML element to the DAV:response element. Its 1430 value is defined only in the context of a particular query result. 1431 The value is a string representing the score, an integer from zero to 1432 10000 inclusive, where a higher value indicates a higher score (e.g. 1433 more relevant). 1435 Modified DTD fragment for DAV:propstat: 1437 1439 1441 Clients should note that, in general, it is not meaningful to compare 1442 the numeric values of scores from two different query results unless 1443 both were executed by the same underlying search system on the same 1444 collection of resources. 1446 5.16.2. Ordering by Score 1448 To order search results by their score, the DAV:score element may be 1449 added as child to the DAV:orderby element (in place of a DAV:prop 1450 element). 1452 5.16.3. Examples 1454 The example below shows a search for the phrase "Peter Forsberg". 1456 Depending on its support for content-based searching, a server MAY 1457 treat this as a search for documents that contain the words "Peter" 1458 and "Forsberg". 1460 1461 Peter Forsberg 1462 1464 The example below shows a search for resources that contain "Peter" 1465 and "Forsberg". 1467 1468 1469 Peter 1470 Forsberg 1471 1472 1474 5.17. Limiting the Result Set 1476 1477 ;only digits 1479 The DAV:limit XML element contains requested limits from the client 1480 to limit the size of the reply or amount of effort expended by the 1481 server. The DAV:nresults XML element contains a requested maximum 1482 number of DAV:response elements to be returned in the response body. 1483 The server MAY disregard this limit. The value of this element is an 1484 integer. 1486 5.17.1. Relationship to Result Ordering 1488 If the result set is both limited by DAV:limit and ordered according 1489 to DAV:orderby, the results that are included in the response 1490 document must be those that order highest. 1492 5.18. The 'caseless' XML Attribute 1494 The "caseless" attribute allows clients to specify caseless matching 1495 behavior instead of character-by-character matching for DAV: 1496 basicsearch operators. 1498 The possible values for "caseless" are "yes" or "no". The default 1499 value is server-specified. Caseless matching SHOULD be implemented 1500 as defined in section 5.18 of the Unicode Standard ([UNICODE4]). 1502 Support for the "caseless" attribute is optional. A server should 1503 respond with a status of 422 if it is used but cannot be supported. 1505 5.19. Query Schema for DAV:basicsearch 1507 The DAV:basicsearch grammar defines a search criteria that is a 1508 Boolean-valued expression, and allows for an arbitrary set of 1509 properties to be included in the result record. The result set may 1510 be sorted on a set of property values. Accordingly the DTD for 1511 schema discovery for this grammar allows the server to express: 1513 1. the set of properties that may be either searched, returned, or 1514 used to sort, and a hint about the data type of such properties 1516 2. the set of optional operators defined by the resource. 1518 5.19.1. DTD for DAV:basicsearch QSD 1520 1521 1522 1523 1526 1527 1528 1529 1530 1532 The DAV:properties element holds a list of descriptions of 1533 properties. 1535 The DAV:operators element describes the optional operators that may 1536 be used in a DAV:where element. 1538 5.19.2. DAV:propdesc Element 1540 Each instance of a DAV:propdesc element describes the property or 1541 properties in the DAV:prop element it contains. All subsequent 1542 elements are descriptions that apply to those properties. All 1543 descriptions are optional and may appear in any order. Servers 1544 SHOULD support all the descriptions defined here, and MAY define 1545 others. 1547 DASL defines five descriptions. The first, DAV:datatype, provides a 1548 hint about the type of the property value, and may be useful to a 1549 user interface prompting for a value. The remaining four (DAV: 1550 searchable, DAV:selectable, DAV:sortable, and DAV:caseless) identify 1551 portions of the query (DAV:where, DAV:select, and DAV:orderby, 1552 respectively). If a property has a description for a section, then 1553 the server MUST allow the property to be used in that section. These 1554 descriptions are optional. If a property does not have such a 1555 description, or is not described at all, then the server MAY still 1556 allow the property to be used in the corresponding section. 1558 5.19.2.1. DAV:any-other-property 1560 This element can be used in place of DAV:prop to describe properties 1561 of WebDAV properties not mentioned in any other DAV:prop element. 1562 For instance, this can be used to indicate that all other properties 1563 are searchable and selectable without giving details about their 1564 types (a typical scenario for dead properties). 1566 5.19.3. The DAV:datatype Property Description 1568 The DAV:datatype element contains a single XML element that provides 1569 a hint about the domain of the property, which may be useful to a 1570 user interface prompting for a value to be used in a query. Data 1571 types are identified by an element name. Where appropriate, a server 1572 SHOULD use the simple data types defined in [XS2]. 1574 1576 Examples from [XS2], Section 3: 1578 +----------------+---------------------+ 1579 | Qualified name | Example | 1580 +----------------+---------------------+ 1581 | xs:boolean | true, false, 1, 0 | 1582 | xs:string | Foobar | 1583 | xs:dateTime | 1994-11-05T08:15:5Z | 1584 | xs:float | .314159265358979E+1 | 1585 | xs:integer | -259, 23 | 1586 +----------------+---------------------+ 1588 If the data type of a property is not given, then the data type 1589 defaults to xs:string. 1591 5.19.4. The DAV:searchable Property Description 1593 1595 If this element is present, then the server MUST allow this property 1596 to appear within a DAV:where element where an operator allows a 1597 property. Allowing a search does not mean that the property is 1598 guaranteed to be defined on every resource in the scope, it only 1599 indicates the server's willingness to check. 1601 5.19.5. The DAV:selectable Property Description 1603 1605 This element indicates that the property may appear in the DAV:select 1606 element. 1608 5.19.6. The DAV:sortable Property Description 1610 This element indicates that the property may appear in the DAV: 1611 orderby element. 1613 1615 5.19.7. The DAV:caseless Property Description 1617 This element only applies to properties whose data type is "xs: 1618 string" and derived data types as per the DAV:datatype property 1619 description. Its presence indicates that compares performed for 1620 searches, and the comparisons for ordering results on the string 1621 property will be caseless (the default is character-by-character). 1623 1625 5.19.8. The DAV:operators XML Element 1627 The DAV:operators element describes every optional operator supported 1628 in a query. (Mandatory operators are not listed since they are 1629 mandatory and permit no variation in syntax.). All optional 1630 operators that are supported MUST be listed in the DAV:operators 1631 element. The listing for an operator consists of the operator (as an 1632 empty element), followed by one element for each operand. The 1633 operand MUST be either DAV:operand-property, DAV:operand-literal or 1634 DAV:operand-typed-literal, which indicate that the operand in the 1635 corresponding position is a property, a literal value or a typed 1636 literal value, respectively. If an operator is polymorphic (allows 1637 more than one operand syntax) then each permitted syntax MUST be 1638 listed separately. 1640 1641 1642 1643 1645 1647 5.19.9. Example of Query Schema for DAV:basicsearch 1649 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1677 This response lists four properties. The data type of the last three 1678 properties is not given, so it defaults to xs:string. All are 1679 selectable, and the first three may be searched. All but the last 1680 may be used in a sort. Of the optional DAV operators, DAV:is-defined 1681 and DAV:like are supported. 1683 Note: The schema discovery defined here does not provide for 1684 discovery of supported values of the "caseless" attribute. This may 1685 require that the reply also list the mandatory operators. 1687 6. Internationalization Considerations 1689 Properties may be language-tagged using the xml:lang attribute (see 1690 [RFC4918], Section 4.3). The optional operators DAV:language-defined 1691 (Section 5.12.1) and DAV:language-matches (Section 5.12.2) allow to 1692 express conditions on the language tagging information. 1694 7. Security Considerations 1696 This section is provided to detail issues concerning security 1697 implications of which DASL applications need to be aware. All of the 1698 security considerations of HTTP/1.1 also apply to DASL. In addition, 1699 this section will include security risks inherent in searching and 1700 retrieval of resource properties and content. 1702 A query must not allow one to retrieve information about values or 1703 existence of properties that one could not obtain via PROPFIND. (e.g. 1704 by use in DAV:orderby, or in expressions on properties.) 1706 A server should prepare for denial of service attacks. For example a 1707 client may issue a query for which the result set is expensive to 1708 calculate or transmit because many resources match or must be 1709 evaluated. 1711 7.1. Implications of XML External Entities 1713 XML supports a facility known as "external entities", defined in 1714 Section 4.2.2 of [XML], which instruct an XML processor to retrieve 1715 and perform an inline include of XML located at a particular URI. An 1716 external XML entity can be used to append or modify the document type 1717 declaration (DTD) associated with an XML document. An external XML 1718 entity can also be used to include XML within the content of an XML 1719 document. For non-validating XML, such as the XML used in this 1720 specification, including an external XML entity is not required by 1721 [XML]. However, [XML] does state that an XML processor may, at its 1722 discretion, include the external XML entity. 1724 External XML entities have no inherent trustworthiness and are 1725 subject to all the attacks that are endemic to any HTTP GET request. 1726 Furthermore, it is possible for an external XML entity to modify the 1727 DTD, and hence affect the final form of an XML document, in the worst 1728 case significantly modifying its semantics, or exposing the XML 1729 processor to the security risks discussed in [RFC3023]. Therefore, 1730 implementers must be aware that external XML entities should be 1731 treated as untrustworthy. 1733 There is also the scalability risk that would accompany a widely 1734 deployed application which made use of external XML entities. In 1735 this situation, it is possible that there would be significant 1736 numbers of requests for one external XML entity, potentially 1737 overloading any server which fields requests for the resource 1738 containing the external XML entity. 1740 8. Scalability 1742 Query grammars are identified by URIs. Applications SHOULD not 1743 attempt to retrieve these URIs even if they appear to be retrievable 1744 (for example, those that begin with "http://") 1746 9. IANA Considerations 1748 This document uses the namespace defined in Section 21 of [RFC4918] 1749 for XML elements. 1751 9.1. HTTP Headers 1753 This document specifies the HTTP header listed below, to be added to 1754 the HTTP header registry defined in [RFC3864]. 1756 9.1.1. DASL 1758 Header field name: DASL 1760 Applicable protocol: http 1762 Status: Experimental 1764 Author/Change controller: IETF 1766 Specification document: this specification (Section 3.2) 1768 10. Contributors 1770 This document is based on prior work on the DASL protocol done by the 1771 WebDAV DASL working group until the year 2000 -- namely by Alan 1772 Babich, Jim Davis, Rick Henderson, Dale Lowry, Saveen Reddy and 1773 Surendra Reddy. 1775 11. Acknowledgements 1777 This document has benefited from thoughtful discussion by Lisa 1778 Dusseault, Sung Kim, Elias Sinderson, Martin Wallmer, Keith 1779 Wannamaker, Jim Whitehead and Kevin Wiggen. 1781 12. References 1782 12.1. Normative References 1784 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1785 Requirement Levels", BCP 14, RFC 2119, March 1997. 1787 [RFC2616] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., 1788 Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext 1789 Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. 1791 [RFC3023] Makoto, M., St.Laurent, S., and D. Kohn, "XML Media 1792 Types", RFC 3023, January 2001. 1794 [RFC3253] Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J. 1795 Whitehead, "Versioning Extensions to WebDAV", RFC 3253, 1796 March 2002. 1798 [RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web 1799 Distributed Authoring and Versioning (WebDAV) Access 1800 Control Protocol", RFC 3744, May 2004. 1802 [RFC4234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax 1803 Specifications: ABNF", RFC 4234, October 2005. 1805 [RFC4437] Whitehead, J., Clemm, G., and J. Reschke, Ed., "Web 1806 Distributed Authoring and Versioning (WebDAV) 1807 Redirect Reference Resources", RFC 4437, March 2006. 1809 [RFC4918] Dusseault, L., Ed., "HTTP Extensions for Web Distributed 1810 Authoring and Versioning (WebDAV)", RFC 4918, June 2007. 1812 [XML] Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E., and 1813 F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fourth 1814 Edition)", W3C REC-xml-20060816, August 2006, 1815 . 1817 [XPATH] Clark, J. and S. DeRose, "XML Path Language (XPath) 1818 Version 1.0", W3C REC-xpath-19991116, November 1999, 1819 . 1821 [XPATHFUNC] 1822 Malhotra, A., Melton, J., and N. Walsh, "XQuery 1.0 and 1823 XPath 2.0 Functions and Operators", W3C REC-xpath- 1824 functions-20070123, January 2007, 1825 . 1827 [XS1] Thompson, H., Beech, D., Maloney, M., Mendelsohn, N., and 1828 World Wide Web Consortium, "XML Schema Part 1: 1829 Structures", W3C REC-xmlschema-1-20041028, October 2004, 1830 . 1832 [XS2] Biron, P., Malhotra, A., and World Wide Web Consortium, 1833 "XML Schema Part 2: Datatypes Second Edition", W3C REC- 1834 xmlschema-2-20041028, October 2004, 1835 . 1837 12.2. Informative References 1839 [DASL] Reddy, S., Lowry, D., Reddy, S., Henderson, R., Davis, J., 1840 and A. Babich, "DAV Searching & Locating", 1841 draft-ietf-dasl-protocol-00 (work in progress), July 1999. 1843 [DASLREQ] Davis, J., Reddy, S., and J. Slein, "Requirements for DAV 1844 Searching and Locating", February 1999, . 1848 This is an updated version of the Internet Draft 1849 "draft-ietf-dasl-requirements-00", but obviously never was 1850 submitted to the IETF. 1852 [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration 1853 Procedures for Message Header Fields", BCP 90, RFC 3864, 1854 September 2004. 1856 [RFC4790] Newman, C., Duerst, M., and A. Gulbrandsen, "Internet 1857 Application Protocol Collation Registry", RFC 4790, 1858 March 2007. 1860 [SQL99] Milton, J., "Database Language SQL Part 2: Foundation 1861 (SQL/Foundation)", ISO ISO/IEC 9075-2:1999 (E), July 1999. 1863 [UNICODE4] 1864 The Unicode Consortium, "The Unicode Standard - Version 1865 4.0", Addison-Wesley , August 2003, 1866 . 1868 ISBN 0321185781 [1] 1870 [draft-ietf-webdav-bind] 1871 Clemm, G., Crawford, J., Reschke, J., Ed., and J. 1872 Whitehead, "Binding Extensions to Web Distributed 1873 Authoring and Versioning (WebDAV)", 1874 draft-ietf-webdav-bind-20 (work in progress), 1875 November 2007. 1877 URIs 1879 [1] 1881 Appendix A. Three-Valued Logic in DAV:basicsearch 1883 ANSI standard three valued logic is used when evaluating the search 1884 condition (as defined in the ANSI standard SQL specifications, for 1885 example in ANSI X3.135-1992, section 8.12, pp. 188-189, section 8.2, 1886 p. 169, General Rule 1)a), etc.). 1888 ANSI standard three valued logic is undoubtedly the most widely 1889 practiced method of dealing with the issues of properties in the 1890 search condition not having a value (e.g., being null or not defined) 1891 for the resource under scan, and with undefined expressions in the 1892 search condition (e.g., division by zero, etc.). Three valued logic 1893 works as follows. 1895 Undefined expressions are expressions for which the value of the 1896 expression is not defined. Undefined expressions are a completely 1897 separate concept from the truth value UNKNOWN, which is, in fact, 1898 well defined. Property names and literal constants are considered 1899 expressions for purposes of this section. If a property in the 1900 current resource under scan has not been set to a value, then the 1901 value of that property is undefined for the resource under scan. 1902 DASL 1.0 has no arithmetic division operator, but if it did, division 1903 by zero would be an undefined arithmetic expression. 1905 If any subpart of an arithmetic, string, or datetime subexpression is 1906 undefined, the whole arithmetic, string, or datetime subexpression is 1907 undefined. 1909 There are no manifest constants to explicitly represent undefined 1910 number, string, or datetime values. 1912 Since a Boolean value is ultimately returned by the search condition, 1913 arithmetic, string, and datetime expressions are always arguments to 1914 other operators. Examples of operators that convert arithmetic, 1915 string, and datetime expressions to Boolean values are the six 1916 relational operators ("greater than", "less than", "equals", etc.). 1917 If either or both operands of a relational operator have undefined 1918 values, then the relational operator evaluates to UNKNOWN. 1919 Otherwise, the relational operator evaluates to TRUE or FALSE, 1920 depending upon the outcome of the comparison. 1922 The Boolean operators DAV:and, DAV:or and DAV:not are evaluated 1923 according to the following rules: 1925 not UNKNOWN = UNKNOWN 1926 UNKNOWN and TRUE = UNKNOWN 1928 UNKNOWN and FALSE = FALSE 1930 UNKNOWN and UNKNOWN = UNKNOWN 1932 UNKNOWN or TRUE = TRUE 1934 UNKNOWN or FALSE = UNKNOWN 1936 UNKNOWN or UNKNOWN = UNKNOWN 1938 Appendix B. Unresolved Issues 1940 This Section summarizes issues which have been raised during the 1941 development of this specification, but for which no resolution could 1942 be found with the constraints in place. At the time of this writing, 1943 not resolving these issues and publishing as "Experimental" seemed to 1944 make more sense than not publishing at all. Future revisions of this 1945 specification should revisit these issues, though. 1947 B.1. Collation Support 1949 Matching and sorting of textual data relies on collations. With 1950 respect to WebDAV SEARCH, a combination of various design approaches 1951 could be used: 1953 o Require server support for specific collations. 1955 o Require that the server can advertise which collations it 1956 supports. 1958 o Allow a client to select the collation to be used. 1960 In practice, the current implementations of WebDAV SEARCH usually 1961 rely on backends they do not control, and for which collation 1962 information may not be available. To make things worse, 1963 implementations of the DAV:basicsearch grammar frequently need to 1964 combine data from multiple underlying stores (such as properties and 1965 full text content), and thus collation support may vary based on the 1966 operator or property. 1968 Another open issue is what collation formalism to support. At the 1969 time of this writing, the two specifications below seem to provide 1970 the necessary framework and thus may be the base for future work on 1971 collation support in WebDAV SEARCH: 1973 1. "Internet Application Protocol Collation Registry" ([RFC4790]). 1975 2. "XQuery 1.0 and XPath 2.0 Functions and Operators" ([XPATHFUNC], 1976 Section 7.3.1). 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 instance, 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 C.14. since draft-reschke-webdav-search-11 2388 Update: draft-newman-i18n-comparator-14 is RFC4790. Update: RFC2518 2389 replaced by draft-ietf-webdav-rfc2518bis. Updated BIND reference. 2390 Minor tweaks to intro (document organization and relation to DASL). 2392 C.15. since draft-reschke-webdav-search-12 2394 Update: draft-ietf-webdav-rfc2518bis replaced by RFC4918. Updated 2395 BIND reference. 2397 C.16. since draft-reschke-webdav-search-13 2399 Open and close issue "qsd-req-validity". Updated BIND reference. 2401 Appendix D. Resolved issues (to be removed by RFC Editor before 2402 publication) 2404 Issues that were either rejected or resolved in this version of this 2405 document. 2407 D.1. qsd-req-validity 2409 In Section 4.1: 2411 Type: change 2413 julian.reschke@greenbytes.de (2007-11-09): Raised by Javier Godoy in 2414 private email: the XML child element below DAV:query-schema-discovery 2415 does not need to be a valid query; and the example in 4.1.1 shows 2416 that. 2418 Resolution (2007-11-09): Apply minimal fix to DTD comment. 2420 Appendix E. Open issues (to be removed by RFC Editor prior to 2421 publication) 2423 E.1. edit 2425 Type: edit 2427 julian.reschke@greenbytes.de (2004-07-05): Umbrella issue for 2428 editorial fixes/enhancements. 2430 Index 2432 C 2433 caseless attribute 27, 33 2434 Condition Names 2435 DAV:search-grammar-discovery-supported (pre) 9 2436 DAV:search-grammar-supported (pre) 9 2437 DAV:search-multiple-scope-supported (pre) 9 2438 DAV:search-scope-valid (pre) 9 2439 Criteria 5 2441 D 2442 DAV:and 26 2443 DAV:ascending 26 2444 DAV:contains 31 2445 DAV:depth 23 2446 DAV:descending 26 2447 DAV:eq 27 2448 caseless attribute 27 2449 DAV:from 23 2450 DAV:gt 27 2451 DAV:gte 27 2452 DAV:include-versions 23 2453 DAV:is-collection 29 2454 DAV:is-defined 30 2455 DAV:language-defined 29 2456 DAV:language-matches 29 2457 DAV:like 30 2458 DAV:limit 33 2459 DAV:literal 27 2460 DAV:lt 27 2461 DAV:lte 27 2462 DAV:not 26 2463 DAV:nresults 33 2464 DAV:or 26 2465 DAV:orderby 26 2466 DAV:scope 23 2467 DAV:score 32 2468 relationship to DAV:orderby 33 2469 DAV:search-grammar-discovery-supported precondition 9 2470 DAV:search-grammar-supported precondition 9 2471 DAV:search-multiple-scope-supported precondition 9 2472 DAV:search-scope-valid precondition 9 2473 DAV:select 23 2474 DAV:supported-query-grammar-set property 14 2475 DAV:typed-literal 27 2476 DAV:where 24 2478 M 2479 Methods 2480 SEARCH 8 2482 O 2483 OPTIONS method 13 2484 DASL response header 14 2486 P 2487 Properties 2488 DAV:supported-query-grammar-set 14 2490 Q 2491 Query Grammar Discovery 13 2492 using live property 14 2493 using OPTIONS 13 2494 Query Grammar 6 2495 Query Schema 6 2496 Query 5 2498 R 2499 Result Record Definition 6 2500 Result Record 6 2501 Result Set Truncation 2502 Example 10 2503 Result Set 6 2504 Result 6 2506 S 2507 Scope 6 2508 SEARCH method 8 2509 Search Modifier 6 2510 Sort Specification 6 2512 Authors' Addresses 2514 Julian F. Reschke (editor) 2515 greenbytes GmbH 2516 Hafenweg 16 2517 Muenster, NW 48155 2518 Germany 2520 Phone: +49 251 2807760 2521 Email: julian.reschke@greenbytes.de 2522 URI: http://greenbytes.de/tech/webdav/ 2523 Surendra Reddy 2524 Optena Corporation 2525 2860 Zanker Road, Suite 201 2526 San Jose, CA 95134 2527 U.S.A. 2529 Phone: +1 408 321 9006 2530 Email: skreddy@optena.com 2532 Jim Davis 2533 27 Borden Street 2534 Toronto, Ontario M5S 2M8 2535 Canada 2537 Phone: +1 416 929 5854 2538 Email: jrd3@alum.mit.edu 2539 URI: http://www.econetwork.net/~jdavis 2541 Alan Babich 2542 Filenet, an IBM company 2543 3565 Harbor Blvd. 2544 Costa Mesa, CA 92626 2545 U.S.A. 2547 Phone: +1 714 327 3403 2548 Email: ababich@us.ibm.com 2550 Full Copyright Statement 2552 Copyright (C) The IETF Trust (2007). 2554 This document is subject to the rights, licenses and restrictions 2555 contained in BCP 78, and except as set forth therein, the authors 2556 retain all their rights. 2558 This document and the information contained herein are provided on an 2559 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 2560 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND 2561 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS 2562 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 2563 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 2564 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 2566 Intellectual Property 2568 The IETF takes no position regarding the validity or scope of any 2569 Intellectual Property Rights or other rights that might be claimed to 2570 pertain to the implementation or use of the technology described in 2571 this document or the extent to which any license under such rights 2572 might or might not be available; nor does it represent that it has 2573 made any independent effort to identify any such rights. 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