INTERNET-DRAFT Chris Kaler, Microsoft, Editor draft-ietf-webdav-versioning-01.txt Jim Amsden, IBM Goeff Clemm, Rational Bruce Cragun, Novell David Durand, BU Bradley Sergeant, Microfocus Jim Whitehead, UC Irvine Expires June 20, 1999 January 20, 1999 Versioning Extensions to WebDAV Status of this Memo This document is an Internet draft. Internet drafts are working documents of the Internet Engineering Task Force (IETF), its areas and its working groups. Note that other groups may also distribute working information as Internet drafts. Internet Drafts are draft documents valid for a maximum of six months and can be updated, replaced or obsoleted by other documents at any time. It is inappropriate to use Internet drafts as reference material or to cite them as other than as "work in progress". To learn the current status of any Internet draft please check the "lid-abstracts.txt" listing contained in the Internet drafts shadow directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ftp.isi.edu (US East coast) or ftp.isi.edu (US West coast). Further information about the IETF can be found at URL: http://www.ietf.org/ Distribution of this document is unlimited. Please send comments to the mailing list at <ietf-dav-versioning@w3.org>, which may be joined by sending a message with subject "subscribe" to <ietf-dav- versioning-request@w3.org>. Discussions of the list are archived at <URL:http://www.w3.org/Archives/Public/ietf-dav-versioning/>. Abstract This document specifies a set of methods, headers, and content- types composing DAV Versioning extensions, an application of the HTTP/1.1 protocol to version DAV resources. Kaler, et. al. [Page 1]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Table of Contents VERSIONING EXTENSIONS TO WEBDAV ...........................1 TABLE OF CONTENTS .........................................2 1. INTRODUCTION ..........................................4 1.1.DAV Versioning ........................................4 1.2.Relationship to DAV ...................................4 1.3.Terms .................................................4 1.4.Definitions ...........................................4 1.5.Notational Conventions ................................5 2. BASIC VERSIONING ......................................5 2.1.Discovery .............................................6 2.2.Immutable and Mutable Properties ......................7 2.3.Versioning a Resource .................................8 2.4.Immutable and Mutable Revisions .......................8 2.5.Versioning and COPY/MOVE ..............................9 2.6.Sharing ...............................................9 2.7.Default Revision .....................................10 2.8.Collection Versioning ................................11 2.9.Basic Revision Properties ............................11 2.10. Basic Versioning Headers ...........................13 2.10.1. Revision-Id .....................................13 2.10.2. Branch-Id .......................................14 2.10.3. Override-Checkin ................................14 2.10.4. Revision-Path ...................................14 3. CHECKING OUT/IN RESOURCES ............................15 3.1.Checkout .............................................15 3.2.Checkin ..............................................17 3.3.Cancelling Checkout ..................................17 3.4.Enumeration ..........................................18 4. BRANCHING RESOURCES ..................................18 5. RESOURCE REPORTS .....................................19 5.1.Available Reports ....................................20 5.2.Default History ......................................21 5.3.Active Checkouts .....................................22 5.4.Direct Lineage .......................................23 5.5.Full Lineage .........................................24 6. CONFIGURATION BASICS .................................26 6.1.Discovery ............................................27 6.2.Creating Configurations ..............................28 6.3.Access Using Configurations ..........................30 6.4.Deleting Configurations ..............................30 6.5.Resolution Queues ....................................30 6.6.Configuration Properties .............................31 6.7.Headers ..............................................32 7. CONFIGURATION REPORTS ................................33 Kaler, et. al. [Page 2]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 7.1.Configuration Derivation .............................33 7.2.Configuration Merge Graph ............................34 8. DYNAMIC CONFIGURATIONS ...............................35 9. WORKSPACE CONFIGURATIONS .............................37 9.1.Managing Configuration Content .......................37 9.2.Default Workspace Configurations .....................38 10. CHECKIN SETS .........................................38 11. VERSION MAPPING ......................................39 11.1. Discovery ..........................................40 11.2. Mapping Configurations .............................41 11.3. Mapping Resource Versions ..........................41 12. THE DAV VERSIONING GRAMMAR ...........................42 13. INTERNATIONALIZATION CONSIDERATIONS ..................42 14. SECURITY CONSIDERATIONS ..............................43 15. SCALABILITY ..........................................43 16. AUTHENTICATION .......................................43 17. IANA CONSIDERATIONS ..................................43 18. COPYRIGHT ............................................43 19. INTELLECTUAL PROPERTY ................................43 20. REFERENCES ...........................................43 21. AUTHOR'S ADDRESSES ...................................44 22. OPEN ISSUES ..........................................44 23. CHANGE HISTORY .......................................45 Kaler, et. al. [Page 3]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 1. INTRODUCTION 1.1. DAV Versioning This document defines DAV Versioning extensions, an application of HTTP/1.1 for handling resource versioning in a DAV environment. [DAVVERREQ] describes the motivation and requirements for DAV Versioning. DAV Versioning will minimize the complexity of clients so as to facilitate widespread deployment of applications capable of utilizing the DAV services. As well, DAV Versioning supports a rich level of versioning options for versioning-aware clients. DAV Versioning consists of: - Automatic versioning support for HTTP/1.1-based clients, - Basic versioning for DAV Versioning-aware clients, - File branching for basic parallel development, and - Configuration support for sophisticated parallel development. 1.2. Relationship to DAV DAV Versioning relies on the resource and property model defined by [WebDAV]. DAV Versioning does not alter this model. Instead, DAV Versioning allows clients to version and access DAV-modeled resources and histories. 1.3. Terms This draft uses the terms defined in [RFC2068], [WebDAV], and [DAVVERREQ]. 1.4. Definitions The section defines several terms that are used throughout the document specific to DAV versioning. Versioned Resource - This refers to a resource that is subject to versioning (independent of any specific version) Revision - This refers to a specific version of a versioned resource Revision History - This refers to the set of changes to a versioned resource Kaler, et. al. [Page 4]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Working Resource - This refers to a resource that is an intermediate revision of a versioned resource. That is, the versioned resource has been "checked out" and this is where changes are made until it is ready to be "checked in". Note that working resources are not versioned. Revision Thread - This refers to a sequence of revisions that have been branched for a specific purpose. Line of Descent - This refers to the sequence of revisions that have occurred from the initial revision to a specified revision. 1.5. Notational Conventions The augmented BNF used by this document to describe protocol elements is exactly the same as the one described in Section 2.1 of [RFC2068]. Because this augmented BNF uses the basic production rules provided in Section 2.2 of [RFC2068], those rules apply to this document as well. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2. BASIC VERSIONING The base level of versioning support defined by this specification includes both automatic versioning and the basic versioning properties defined for all resources. To support basic versioning, resources MUST allow for versioning to occur automatically on selected resources whenever immutable aspects are changed, and support the properties defined in this section. Resources that support DAV:versioning MUST also provide additional versioning semantics for versioning-aware clients. This section describes these new semantics which include enhancements to existing DAV methods, new headers, and new versioning-specific methods. Although the semantics can vary, most versioning systems support the notion of indicating intent to modify a document (check-out) and then submission of the modified version (check-in). Typically this involves some form of locking (either shared or exclusive). As well, many systems support the ability to cancel a check-out or undo a recent check-in. These options are available to the owner or to the Administrator. Users can generally enumerate the current check-outs although they may not be able to determine the user in all cases. Likewise, users can review check-ins to see the change history. Most systems allow users to select different versions from the change history and present a comparison of the versions. Kaler, et. al. [Page 5]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Note that locks are not covered in this specification as they are addressed by [WebDAV]. 2.1. Discovery The OPTIONS method allows the client to discover if a resource supports versioning. The presence of Versioning in the response header indicates support for DAV versioning. This header indicates the level of support. The following defines the BNF for the Versioning header: Versioning := "Versioning" ":" URI The valid values of the URI are: - DAV:basicversioning - TBD This example shows that the /somefolder resource supports versioning. >> Request OPTIONS /somefolder/ HTTP/1.1 Host: foobar.com Content-Length: 0 >> Response HTTP/1.1 200 OK Date: Tue, 20 Jan 1998 20:52:29 GMT Connection: close Accept-Ranges: none Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Public: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Versioning: DAV:basicversioning Content-Length: 0 Since some aspects of DAV versioning require clients to know additional information, clients can include a request body that specifies that DAV versioning information is desired. The information is returned in the response body, formatted in XML. Kaler, et. al. [Page 6]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 >> Request OPTIONS /somefolder/ HTTP/1.1 Host: foobar.com Content-Length: xxx Content-Type: text/xml <?xml version="1.0" encoding="utf-8" ?> <D:options xmlns:D="DAV:"> <D:verinfo/> </D:options> >> Response HTTP/1.1 200 OK Date: Tue, 20 Jan 1998 20:52:29 GMT Connection: close Accept-Ranges: none Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Public: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Versioning: DAV:basicversioning Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:options xmlns:D="DAV:"> <D:verinfo> ... </D:verinfo> </D:options> The details of the tags returned are described throughout this specification. 2.2. Immutable and Mutable Properties An immutable property is defined as a property that, when changed, causes a new revision of a versioned resource to be created. Likewise, a mutable property is a property that can be changed without having a new revision created. Resources can support both mutable and immutable properties although there MAY be restrictions that the mutability is consistent across all resources. This specification doesn't cover the discovery or management of property mutability. Kaler, et. al. [Page 7]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 2.3. Versioning a Resource By default, a resource may not be subject to versioning. This can be discovered by examining the DAV:isversioned property. To place a non-versioned resource under version control, clients use the VERSION method and specify the URI of the resource to version. Note that if the specified resource is a collection, then the Depth header is used to identify the scope of the operation. A depth of infinity is assumed by default. The DAV:isautoversioned property indicates if a resource is automatically versioned when any immutable aspect of it is changed. Resources with automatic versioning allow HTTP/1.1 clients to have changes versioned without explicit versioning commands. This applies to any method that modifies a resource (e.g., PUT, MKCOL, COPY, MOVE, DELETE, PROPPATCH, ...) Using the DAV:versioningenabled and DAV:autoversioning tags, clients can establish the versioning policy. >> Request VERSION /somefolder/ HTTP/1.1 Host: foobar.com Depth: infinity Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:versioning xmlns:D="DAV:"> <D:versioningenabled>On</D:versioningenabled> <D:autoversioning>On</D:autoversioning> </D:versioning> >> Response HTTP/1.1 200 OK Content-Length: 0 2.4. Immutable and Mutable Revisions By default, the contents of a revision are immutable. That is, once a revision is created, it cannot be altered. However, in many document management systems this is not the case. To address these scenarios, the THAW/FREEZE methods are introduced. Note that support for THAW and FREEZE are optional, but these operations MUST fail if not supported. The THAW method specifies that the indicated revision should be made mutable so that subsequent methods can alter the immutable aspects of the resource. The FREEZE method indicates that all changes have been made and the revision should be marked immutable again. Kaler, et. al. [Page 8]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 The DAV:canthaw property indicates if a revision can be thawed. Similarly, the DAV:hasthawed property indicates if a revision has ever been thawed. Finally, the DAV:isthawed property specifies if the revision is currently thawed (frozen if not). The following example shows the use of THAW and FREEZE. >>Request THAW /foo/bar.htm HTTP/1.1 Revision-Id: VER:FHF45409 Host: www.foobar.com Content-Length: 0 ... PUT /foo/bar.htm HTTP/1.1 Revision-Id: VER:FHF45409 Host: www.foobar.com Content-Length: xxx ... FREEZE /foo/bar.htm HTTP/1.1 Revision-Id: VER:FHF45409 Host: www.foobar.com Content-Length: 0 ... 2.5. Versioning and COPY/MOVE When a COPY method is issued against a versioned resource or revision, only the "current" revision of the versioned resource or the specified revision is copied to the specified destination. That is, the entire history is NOT copied. When a MOVE method is issued against a versioned resource the "move" SHOULD be represented in the revision history. That is, a MOVE operation CANNOT be represented as a delete and an add. A MOVE operation cannot be issued against a specific revision. 2.6. Sharing Many versioning systems today provide the ability to have a given resource visible in multiple parts of the namespace. In these situations, a resource is shared. That is, changes to the resource are visible to all versions. The WebDAV Advanced Collections working group addresses this need with direct referential members. Support for direct referential members is required for DAV versioning. Kaler, et. al. [Page 9]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 2.7. Default Revision If a Revision-Id (or Branch-Id) header is not specified when referring to a resource, then the tip (latest) revision (from the primary branch) is used, unless a default revision has been identified. To mark a specified revision as the default revision, clients use the SETDEFAULT method. Note that PUT or CHECKIN will remove any default version. Also note that branching a resource has no effect on the default revision of the resource, even if the default revision is branched. If the default is removed, the default revision is the tip revision of the initial (primary) branch of the versioned resource. Setting the default revision to DAV:none cancels the default revision. >>Request SETDEFAULT /foo/bar.htm HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:setdefault xmlns:D="DAV:"> <D:href>VER:HT58GHDW49</D:href> </D:setdefault> >>Response HTTP/1.1 200 OK Content-Length: 0 >>Request SETDEFAULT /foo/bar.htm HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:setdefault xmlns:D="DAV:"> <D:none/> </D:setdefault> >>Response HTTP/1.1 200 OK Content-Length: 0 If a resource is shared, servers MUST support the ability to set different default revisions at each point of the share. Kaler, et. al. [Page 10]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Clients can determine the default revision by examining the DAV:revisionid from the default revision. >>Request PROPFIND /foo/bar.htm HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:prop> <D:revisionid/> </D:prop> </D:propfind> 2.8. Collection Versioning Collections can be versioned just like non-collection resources, however, they are only versioned when a direct change is made to the collection. It is up to each collection resource to determine if it supports default versions. If it doesn't, then SETDEFAULT requests MUST fail. The Revision-Path header is used to identify specific revisions that are part of the "path" to the resource. This header servers as an alternative to "URL munging". This header can be specified on all methods and qualifies the resource named in the method. 2.9. Basic Revision Properties For resources that support versioning, they MUST support the following properties using the "DAV:" namespace. Note that 0/1 is used as a FALSE (0) / TRUE (1) indicator. DAV:isversioned - 0/1 to indicate if the resource is versionable. Note that this can be implemented as a read-only property. DAV:autoversion - 0/1 to indicate if the resource is automatically versioned when modified. Note that this can be implemented this as a read-only property. DAV:revisionid - This is a read-only property that returns a server determined id for this specific revision of the resource. Every revision of a resource will have a unique DAV:revisionid. A revision id may be a URL or it may be an arbitrary server-defined string. However, it cannot contain the "," character. Because it is not required to be a URL, the DAV:revisionurl property is required to obtain a URI for the specific revision of the resource. Kaler, et. al. [Page 11]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 DAV:vresourceid - This is a read-only property that returns a server determined id for the versioned resource. That is, all revisions of the resource have the same DAV:vresourceid. This MUST be preserved over MOVE requests and should be globally unique. DAV:previousrevisionids - This is a read-only property that returns the server defined id for the previous revision of the resource. An empty value indicates that there are no previous revisions. Note that there could be multiple previous versions. If there are multiple revisions, they are returned as a comma-separated list. Note that this property returns previous revisions that the server determines. That is, this does not include user identified merged revisions. DAV:distinguishedpredecessorid - This read-only property indicates the primary predecessor for a revision in the event they are multiple predecessors. DAV:nextrevisionids - This is a read-only property that returns the server defined id for the next revision of the resource. An empty value indicates that there is no subsequent revision. Note that there could be multiple next revisions. If there are multiple revisions, they are returned as a comma-separated list. Note that this property returns successor revisions that the server determines. That is, this does not include user identified merged revisions. DAV:revisionurl - This is a read-only property that returns a URL for this specific revision. DAV:revisionlabel - This property allows the specification of textual names that refer to this version of the resource. If there are multiple labels, they are returned as a comma separated list. Labels MUST be unique for the versioned resource. That is, no two revisions of the same versioned resource can have the same DAV:revisionlabel. As well, DAV:revisionlabel and DAV:revisionid properties share the same namespace and there can be no duplicates. Servers MAY reserve specific portions of this namespace and return an error if a client uses a reserved name as a revision label. This property MUST be mutable. DAV:mergedfrom - This property specifies a comma separated list of revision ids from which this revision is purported to be derived. This information is provided and managed by the client. This is a mutable property. DAV:mergedto - This property specifies a comma separated list of revision ids from which this revision is purported to be merged into. This information is provided and managed by the client. This is a mutable property. DAV:mergedfromunion - This read-only property specified a comma separated list of revision ids from which this revision is derived. Kaler, et. al. [Page 12]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 This is a union of the DAV:mergedfrom and DAV:previousrevisionids properties. DAV:revisioncomment - This property contains a client-defined property associated with the revision. This as a mutable property. This is a mutable property. DAV:author - The creator of the revision. This is an arbitrary string. DAV:canthaw - This property indicates if the revision can be THAWed for modification. Servers MAY implement this as read-only. DAV:hasthawed - This read-only property indicates if the revision has ever been thawed. DAV:isthawed - This read-only property indicates if the revision is currently thawed (or frozen if not). DAV:lastcheckin - This read-only property specifies the date this revision was "checked in" in ISO8601 format. 2.10. Basic Versioning Headers The following sub-sections describe the new version headers that MUST be supported for resources that support DAV:versioning. 2.10.1. Revision-Id The Revision-Id header is used to identify a specific revision of a versioned resource. This header can be specified on all methods and qualifies the resource named in the method. As well, this header is included in all replies to indicate the revision of the versioned resource used or created. The BNF for this header is as follows. Revision-Id := "Revision-Id" ":" RID RID := "*" | Time-Ref | ANY Time-Ref := "Time" "(" ISO8601 ")" This property allows the specification of criteria that selects a specific revision of a resource. This includes a DAV:revisionid or any of the DAV:revisionlabel values to refer to a specific revision of the resource. As well, a configuration (described later) can be referenced here to select the default revision associated with the configuration. The use of the Time operator is to select the "current" revision as of the specified time. Kaler, et. al. [Page 13]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 The use of Revision-Id: * is only permitted with PROPFIND to obtain properties across all revisions of a versioned resource. 2.10.2. Branch-Id The Branch-Id header is used to identify a branch (revision thread). The BNF for the header is as follows: Branch-Id := "Branch-Id" ":" ANY The Branch-Id can be used anywhere a revision-id is used. When specified, it indicates that the latest version of the indicated branch is to be selected as the revision to use for the operation. 2.10.3. Override-Checkin It is possible that the check-in operation will detect a conflict. For example, version 5 was checked out shared, and before it is checked back in, version 6 was created. In these situations, the check-in MUST fail indicating a conflict. Clients can choose to branch the resource, merge on the client, or overwrite. To circumvent this check, clients can use the Override-Checkin header. This specifies that the check-in operation SHOULD NOT fail (either the client has merged to resolve the conflict, or desires an overwrite). The BNF is as follows: Override-Checkin := "Override-Checkin" ":" ("Yes" | "No") 2.10.4. Revision-Path The Revision-Path header allows clients to identify specific versions of collections that should be used rather than the default revisions. The BNF for this header is as follows. Revision-Path := "Revision-Path" ":" Path Path := PItem | (Path PItem) PItem := "/" ANY Rev Rev := | (";" RID) RID := "*" | ANY | "(" ANY ")" >>Request GET /foo/bar.htm HTTP/1.1 Host: www.foobar.com Revision-Path: /foo;VER:HT58GHDW49/bar.htm Content-Length: 0 The use of * for a revision is only permitted with PROPFIND to obtain properties across all revisions of a versioned resource. Kaler, et. al. [Page 14]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 3. CHECKING OUT/IN RESOURCES For versioning-aware clients, more advanced requests allow them to perform specific versioning operations. These methods are directed at a specific URI to alter. If a resource supports DAV:versioning then it MUST support the methods defined in this section. 3.1. Checkout Using the CHECKOUT method, clients can request resources to be "checked out". This involves creating a working resource that is not automatically versioned. Checked out resources must be checked in or cancelled. The diagram below illustrates this process: Revisions of foo.htm: V1 Checkout is performed: V1 | +-> Working Resource Checkin is performed: V1 -> V2 The body XML indicates an optional checkout comment, an optional user token, and locking actions. The response indicates the working resource as well as any requested locks. The CHECKOUT method causes the creation of the working copy which is specified by the Location header in the response. Clients can optionally request locks to be taken as part of the CHECKOUT operation. If the locks cannot be obtained, the CHECKOUT operation MUST fail. The following table identifies the different lock options: Lock Tags Used Description Target (DAV: assumed) working wrlocktype, Limits access to the newly created resource wrlockscope working resource revision revisionlockty Blocks CHECKOUT/INs against this pe, revision revisionlocksc ope Kaler, et. al. [Page 15]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 branch branchlocktype Blocks CHECKOUT/INs against , revisions in this branch branchlockscop e versioned vrlocktype, Blocks CHECKOUT/INs against any resource vrlockscope revision of the versioned resource. The semantics of the tags match those of DAV:locktype and DAV:lockscope as specified for the LOCK method. >>Request CHECKOUT /foo/bar HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:checkout xmlns:D="DAV:"> <D:comment>checkout comment</D:comment> <D:owner>client-defined token</D:owner> <D:wrlocktype><D:write/></D:locktype> <D:wrlockscope><D:exclusive/></D:lockscope> </D:checkout> >>Response HTTP/1.1 201 CREATED Location: http://www.foobar.com/tmp/VRJHJWE3493409 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8"?> <D:prop xmlns:D="DAV:"> <D:lockdiscovery> <D:activelock> <D:wrlocktype><D:write/></D:locktype> <D:wrlockscope><D:exclusive/><D:lockscope> <D:owner>client-define token</D:owner> <D:locktoken> <D:href>opaquelocktoken:rejrei-43343-rereffre</D:href> </D:locktoken> </D:activelock> </D:lockdiscovery> </D:prop> Servers MUST fail this operation if a branch is required. Kaler, et. al. [Page 16]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 3.2. Checkin When the client has completed changes to a resource and wishes it to become part of the revision history, the client must check in the resource. This is performed using the CHECKIN method against the working copy. The DAV:keepcheckedout tag can be specified to indicate that the resource should remain checked out. That is, create a new revision, but leave the working copy checked out. Using XML tags in the request body, clients can specify optional checkin information. >>Request CHECKIN /tmp/VRJHJWE3493409 HTTP/1.1 Host: www.foobar.com Lock-Token: <opaquelocktoken:rejrei-43343-rereffre> Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:checkin xmlns:D="DAV:"> <D:comment>checkin comment</D:comment> </D:checkin> >>Response HTTP/1.1 201 CREATED Revision-Id: VER:FREFRI49349 Content-Length: 0 The reply MUST include the Revision-Id of the newly created revision. It is possible that the check-in operation will detect a conflict. Servers MUST fail this operation if a branch is required. The Override-Checkin header is used to resolve these conflicts. 3.3. Cancelling Checkout If a client chooses to cancel a checkout request, the UNCHECKOUT method against the working copy. As well, optional XML body tags can be used to supply additional information. >>Request UNCHECKOUT /tmp/VRJHJWE3493409 HTTP/1.1 Host: www.foobar.com Lock-Token: <opaquelocktoken:rejrei-43343-rereffre> Content-Type: text/xml Content-Length: xxxxx Kaler, et. al. [Page 17]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <?xml version="1.0" encoding="utf-8" ?> <D:uncheckout xmlns:D="DAV:"> <D:comment>cancel checkout comment</D:comment> </D:uncheckout> >>Response HTTP/1.1 200 OK Content-Length: 0 3.4. Enumeration Refer to the Resource Reports section for details on check-out enumeration. 4. BRANCHING RESOURCES For more sophisticated clients, basic resource branching is required. Resource branching means that for a given resource, the history is not linear. That is, there are different lines of descent. The diagram below illustrates this. Revision history V1 -> V2 -> V3 Of foo.htm: | +-> V1.1 -> V1.2 | +-> V1.1.1 Individual resource branching is common in many versioning systems today. Project branching (configurations) are described in a later section. Note that when a collection is branched, the depth of the branch is infinity. There is no way to change this. A revision is branched using the BRANCH method. The resource to be branched is specified as the target URI for the method. As well, clients can specify a branch label to identify a created branch using the DAV:branchlabel tag. The reply MUST include a Branch-Id header specifying a resource defined branch id or the specified branch label if a branch is created. The label or id can be specified in a Branch-Id or Revision-Id header to determine the revision to access. >>Request BRANCH VER:FHHR4959 HTTP/1.1 Host: www.foobar.com Content-Type: text/html Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:branch xmlns:D="DAV:"> Kaler, et. al. [Page 18]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <D:branchlabel>MyBranch</D:branchlabel> <D:comment>branch comment</D:comment> </D:branch> >>Response HTTP/1.1 201 CREATED Branch-Id: MyBranch Revision-Id: VER:REUU48583 Content-Length: 0 When a branch is created, the reply MUST include a Branch-Id header. 5. RESOURCE REPORTS Revision history graphs and other reports of a resource are accessed via PROPFIND. Note that resources MAY support multiple styles of history and reports. To enumerate the supported history graphs and reports, clients use PROPFIND and the <DAV:availablereports> property. The results indicate a list of the different reports which can, themselves, be requested via PROPFIND. For the examples in this section, assume that the resource /foo.htm has the following revision graph: Revision history V1 -> V2 -> V3 Of foo.htm: | +-> V1.1 -> V1.2 | +-> V1.1.1 Clients have specified the following merge annotations: - V1.2 is a merge of V1.1 and V1.1.1 - V3 is a merge of V2 and V1.2 As well, the default revision history (those revisions marked as the default) is as follows: - V1 (the initial revision was created) - V2 (a new revision was created) - V1 (a client changed the default revision) - V3 (an updated revision was created) Also, the following labels have been specified: Kaler, et. al. [Page 19]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 - V2: Test1 - V1.1: Test2, Good - V1.2: Tested Additionally, when the V1.1 branch was created, it was labeled "MyBranch". 5.1. Available Reports Clients can obtain the available reports for a resource by obtaining its DAV:availablereports property. >>Request PROPFIND /foo/bar.htm HTTP/1.1 Host: www.foobar.com Depth: 0 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:prop> <D:availablereports/> </D:prop> </D:propfind> >>Response ... <D:multistatus> <D:response> <D:href>http:/www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:availablereports> <D:report>DAV:defaulthistory</D:report> <D:report>DAV:directlineage</D:report> <D:report>DAV:fulllineage</D:report> </D:availablereports> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> ... Note that the report styles MUST be specified as DAV:href values. Kaler, et. al. [Page 20]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 When clients issue PROPFIND requests to obtain reports, they may include other properties in the request. These properties are returned for each report item. 5.2. Default History Resources MUST support the DAV:defaulthistory report. This enumerates the historical record of revisions that have been visible as the default revision. Clients can specify the limit parameter to limit the number revisions returned. By definition, revisions are returned in reverse chronological order starting with the most recent. >>Request PROPFIND /foo/bar.htm HTTP/1.1 Host: www.foobar.com Depth: 0 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:defaulthistory limit=20/> </D:propfind> >>Response ... <D:multistatus> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V3</D:revision> <D:revisioncomment>Update it</D:comment> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V1</D:revision> <D:revisioncomment>Update it</D:comment> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> Kaler, et. al. [Page 21]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <D:propstat> <D:prop> <D:revisionid>V2</D:revision> <D:revisioncomment>Update it</D:comment> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V1</D:revision> <D:revisioncomment>Update it</D:comment> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> 5.3. Active Checkouts Clients can obtain a list of the active checkouts against a resource using PROPFIND and DAV:activecheckouts. >>Request PROPFIND /foo/bar.htm HTTP/1.1 Host: www.foobar.com Revision-Id: VER:FHRJ494059 Depth: 0 Content-Type: text/xml Content-Length: xxxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:activecheckouts/> </D:propfind> >>Response HTTP/1.1 207 Multi-Status Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:checkout> <D:owner>user-specified</D:owner> <D:revisionid>VER:FHER4949</D:revision> Kaler, et. al. [Page 22]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:workingcopy> <D:href>http://www.foobar.com/tmp/FHFH34949</D:href> </D:workingcopy> </D:checkout> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> 5.4. Direct Lineage Resources SHOULD support the DAV:directlineage report. This enumerates the direct parent revisions of the resource. Clients can request that a report be based on the namespace entry specified, or the associated DAV:vresourceid. Clients use the scope parameter to specify (name or id). Clients can specify the limit parameter to limit the number revisions returned. >>Request PROPFIND /foo/bar.htm HTTP/1.1 Host: www.foobar.com Depth: 0 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:directlineage scope="name"/> </D:propfind> >>Response ... <D:multistatus> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V1</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> Kaler, et. al. [Page 23]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <D:prop> <D:revisionid>V2</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> <D:derivedfrom>V1</D:derivedfrom> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V3</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> <D:derivedfrom>V3</D:derivedfrom> <D:revisionlabel>Test1</D:label> <D:mergedfrom>V2</D:mergedfrom> <D:mergedfrom>V1.2</D:mergedfrom> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> 5.5. Full Lineage Resources SHOULD support the DAV:fulllineage report. This enumerates the full graph of revisions for this resource. Clients can request that a report be based on the namespace entry specified, or the associated DAV:vresourceid. Clients use the scope parameter to specify (name or id). Clients can specify the limit parameter to limit the number revisions returned. >>Request PROPFIND /foo/bar.htm HTTP/1.1 Host: www.foobar.com Depth: 0 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:fulllineage scope="name"/> </D:propfind> >>Response ... Kaler, et. al. [Page 24]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <D:multistatus> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V1</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V2</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> <D:derivedfrom>V1</D:derivedfrom> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V3</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> <D:derivedfrom>V2</D:derivedfrom> <D:revisionlabel>Test1</D:label> <D:mergedfrom>V2</D:mergedfrom> <D:mergedfrom>V1.2</D:mergedfrom> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V1.1</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> <D:derivedfrom>V1</D:derivedfrom> <D:revisionlabel>Test2</D:label> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> Kaler, et. al. [Page 25]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <D:propstat> <D:prop> <D:revisionid>V1.2</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> <D:derivedfrom>V1.1</D:derivedfrom> <D:branchid>MyBranch</D:branchid> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http://www.foobar.com/foo/bar.htm</D:href> <D:propstat> <D:prop> <D:revisionid>V1.1.1</D:revision> <D:vresourceid>VER:FFHJE</D:vresource> <D:revisioncomment>Update it</D:comment> <D:derivedfrom>V1.1</D:derivedfrom> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> 6. CONFIGURATION BASICS Many clients require more sophisticated management and organization of their versioned data. For this reason, configuration support is defined as part of this specification. Configuration management is a large space. This specification addresses several types of configurations: - Dynamic: A dynamic configuration is a collection of specific revisions of selected versioned resources based on selection rules. This can be used for labels, floating labels, etc. - Workspace: A workspace configuration is a mechanism for tracking and managing parallel changes to multiple resources. Configurations provide a mechanism for organizing resources and quick access to specific revisions of resources. Clients can access resources in the context of a configuration. By referencing a configuration, requests are automatically mapped to the correct revision of the versioned resource. This allows configurations to be used as a reference mechanism without breaking URL hyperlinks. A configuration can be derived from another configuration. That is, the new configuration is based on the versions in the "parent" configuration. Optionally, derived configurations can automatically inherit new versions in the parent configuration (assuming there are no conflicts). However, a configuration can be derived from at most one other configuration. Kaler, et. al. [Page 26]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Clients can specify configuration ids wherever a revision id can be specified. This requests that the default revision for the specified configuration be used. Requests that include both a revision id and a configuration id MUST fail if the specified revision is not part of the specified configuration. Typically both a revision id and a configuration id are not needed since the revision URI is unique across all configurations. 6.1. Discovery Configuration support is optional. This example shows that the /somefolder resource supports configurations. >> Request OPTIONS /somefolder/ HTTP/1.1 Host: www.foobar.com Content-Length: xxx Content-Type: text/xml <?xml version="1.0" encoding="utf-8" ?> <D:options xmlns:D="DAV:"> <D:verinfo/> </D:options> >> Response HTTP/1.1 200 OK Date: Tue, 20 Jan 1998 20:52:29 GMT Connection: close Accept-Ranges: none Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Public: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Versioning: DAV:basicversioning Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:options xmlns:D="DAV:"> <D:verinfo> <D:configroot> <D:href>http://www.foobar.com/cfgs/</D:href> </D:configroot> </D:verinfo> </D:options> Kaler, et. al. [Page 27]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 6.2. Creating Configurations Servers maintain configurations in a private portion of the namespace. The root of this namespace is determined by examining the OPTIONS extended reply. All configurations names MUST be unique on a server. Using the configuration namespace, clients can create and manage configurations. Clients create new configurations by issuing the MKCONFIG method against the configuration namespace. This requests the server to create a new configuration. When a configuration is created, special tags can be used to define the characteristics and relationships (e.g. derivations) for the configuration. The following table enumerates these tags. Tag Description <DAV:configurationtype> This tag defines the type of configuration: xxx DAV:Dynamic or </DAV:configurationtype> DAV:Workspace. <DAV:derivedfrom> This tag allows the client "xxx" to specify a URI to </DAV:derivedfrom> identify another configuration from which this new configuration is to be derived. <DAV:inheritancetype> The configuration automatically inherits DAV:Auto changes from its derived- </DAV:inheritancetype> from configuration. Conflicts are recorded in resolution queues (see later section). <DAV:inheritancetype> The configuration inherits changes from its derived- DAV:Manual from configuration, but </DAV:inheritancetype> they are not automatically inserted into the configuration. Instead they are recorded in resolution queues (see Kaler, et. al. [Page 28]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Tag Description later section). <DAV:inheritancetype> snapshot of the current DAV:None versions in the derived- DAV:inheritancetype> from configuration. There The configuration is a is no inheritance of changes. This is the default type if no type is specified. <DAV:basetime>"xxx" The configuration is based </DAV:basetime> on the current versions in the derived-from configuration at the indicated time. Note that use of this tag is incompatible with DAV:Auto inheritance types and usage in this way MUST return an error. When a non-derived configuration is created, it contains no resources. Configurations that are derived from another configuration include the resources in the derived from configuration at the specified time or using the default revisions. The example below illustrates creating a new configuration that is derived from, and auto-inherits another configuration. For this example, the root of the configuration namespace has been determined to be /cfgs. >>Request MKCONFIG /cfgs/ HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:createconfiguration xmlns:D="DAV:"> <D:configurationtype>DAV:Workspace</D:configurationtype> <D:derivedfrom>http://www.foobar.com/cfgs/DDEJRJ445</D:derivedfrom> <D:inherit>Auto</D:inherit> Kaler, et. al. [Page 29]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 </D:createconfiguration> >>Response HTTP/1.1 201 Created Location: http://www.foobar.com/cfgs/RYURUS99009 Content-Length: 0 6.3. Access Using Configurations Configurations are maintained as a special collection. Configurations maintain referential members to all revisions that are part of the configuration. Consequently, one approach to enumerating the contents of a configuration is to use PROPFIND to discover the contents of the collection. Alternatively, clients can request a specific resource from a configuration. This approach allows clients to use the URL they are familiar with. If a client requests a resource that is not part of a configuration, then an error is returned. >>Request GET /foo/bar.htm HTTP/1.1 Host: www.foobar.com Configuration-Id: /cfgs/DFEE2034 Content-Length: 0 6.4. Deleting Configurations To delete a configuration, use the location returned from the configuration creation. Note that configurations SHOULD NOT allow delete if other configurations are derived from them. >>Request DELETE /cfgs/RYURUS99009 HTTP/1.1 Host: www.foobar.com Content-Length: 0 6.5. Resolution Queues There are times when an operation cannot be blocked that will result in a state that requires user action. For example, when configurations inherit, there is the potential for conflicts. Resolution queues provide a mechanism for discovering these conditions. Configurations track and maintain a list of issues that need to be resolved as a result of actions. These lists are referred to as resolution queues. Clients can request the resolution issues and react accordingly. The configuration will continue to report the condition until it is resolved. Kaler, et. al. [Page 30]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 The resolution queue is obtained by obtaining the DAV:resolutionqueue property from the configuration. This property contains all of the identified issues. >>Request PROPFIND /cfgs/FDJE4949 HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:prop> <D:resolutionqueue/> </D:prop> </D:propfind> >>Response HTTP/1.1 207 Multi-Status Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>http://www.foobar.com/cfgs/FDJE4949</D:href> <D:propstat> <D:prop> <D:resolutionqueue> <D:resolutionitem xmlns:D="DAV:"> <D:resolutiontype><D:conflict/></D:resolutiontype> <D:resource>http:/foo/bar.htm</D:resource> <D:newversion>DAV:FDFEE55544</D:newversion> </D:resolutionitem> </D:resolutionqueue> </D:prop> </D:propstat> </D:response> </D:multistatus> Once a client has resolved an issue it will automatically be removed from the resolution queue. 6.6. Configuration Properties The standard PROPFIND and PROPPATCH methods can be used on the configuration resource to get and set properties on a configuration. Configurations MUST provide configuration properties if configurations are supported. The following list identifies pre-defined properties that MUST be supported: Kaler, et. al. [Page 31]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 DAV:configurationtype - The type of the configuration. Configurations can choose to make this a read-only property. DAV:derivedfrom - The configuration from which the configuration is derived. Configurations can choose to make this a read-only property. DAV:inheritancetype - The type of inheritance for the configuration. Configurations can choose to make this a read-only property. DAV:basetime - The base time used to create the configuration. Configurations can choose to make this a read-only property. DAV:defaultconfiguration - This property on the configuration root identifies the default workspace configuration to use if one is not specified. DAV:resolutionqueue - A list of identified issues that require client attention. 6.7. Headers To support configurations, two new headers are introduced that can be used with a variety of the DAV and HTTP methods. The following list identifies these headers: Configuration-Id - This header is used to identify the configuration that is to be used when performing an operation. For workspace configurations, this can be specified to set default revisions per-configuration, enumeration of checkouts/checkins against a specific configuration, or to establish locks specific to a configuration. If a configuration is not specified, the default workspace configuration is used. All servers have a default workspace where resources reside. The configuration "*" can be specified with PROPFIND to locate properties irrespective of configuration. Configuration-Id := "Configuration-Id" ":" (URL | "*") Note that the configuration id can be used in place of a revision id. In this case, the revision selected is the default revision of the versioned resource within the specified configuration. Target-Configuration - This header is used to specify a target configuration when dealing with cross-configuration operations. For example, resources can be copied from one configuration to another using the Configuration-Id and Target-Configuration headers with the COPY method. Note that resources CANNOT be MOVEd from one configuration to another. Kaler, et. al. [Page 32]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Target-Configuration := "Target-Configuration" ":" URL 7. CONFIGURATION REPORTS Revision history and configuration dependency graphs are accessed via PROPFIND. Note that configurations MAY support multiple styles of history and dependency. To enumerate the supported history graphs, clients use PROPFIND and the <DAV:availablereports> property. The results indicate the different graphs and reports, which can, themselves, be requested via PROPFIND. >>Request PROPFIND /cfgs/FHJRH3994 HTTP/1.1 Host: www.foobar.com Depth: 0 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:prop> <D:enumreport/> </D:prop> </D:propfind> >>Response ... <D:multistatus> <D:response> <D:href>http://www.foobar.com/cfgs/FHJRH3994</D:href> <D:propstat> <D:prop> <D:enumreport> <D:report>DAV:configurationderivation</D:report> <D:report>DAV:configurationmerge</D:report> </D:enumreport> </D:prop> </D:propstat> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> ... When clients issue PROPFIND requests to obtain reports, they may include other properties in the request. These properties are returned for each report item. 7.1. Configuration Derivation Configurations MUST support the DAV:configurationderivation report. This enumerates the full derivation of a configuraiton. Note that Kaler, et. al. [Page 33]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 the limit parameter can be specified to limit the number of items returned. By definition the order of the configurations is immediate predecessor. >>Request PROPFIND /cfgs/BHFR59593 HTTP/1.1 Host: www.foobar.com Depth: 0 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:configurationderivation limit=100/> </D:propfind> >>Response ... <D:multistatus> <D:response> <D:href>http:/www.foobar.com/cfgs/234</D:href> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http:/www.foobar.com/cfgs/345</D:href> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> ... 7.2. Configuration Merge Graph Configurations SHOULD support the DAV:configurationmerge report. This enumerates the derivation of a configuration including merges from one configuration to another. >>Request PROPFIND /cfgs/BHFR59593 HTTP/1.1 Host: www.foobar.com Depth: 0 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:configurationmerge/> </D:propfind> >>Response ... Kaler, et. al. [Page 34]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 <D:multistatus> <D:response> <D:href>http:/www.foobar.com/cfgs/234</D:href> <D:status>HTTP/1.1 200 OK</D:status> </D:response> <D:response> <D:href>http:/www.foobar.com/cfgs/3FF</D:href> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus> ... 8. DYNAMIC CONFIGURATIONS Dynamic configurations provide a mechanism to identify all revisions that match specific criteria. For example, "all revisions that have the label Beta1". The dynamic configuration is a view onto the resources and is updated automatically as resources and revisions are created, deleted, and modified. All dynamic configurations support the DAV:rsrtypes property. This identifies the different styles of dynamic configurations to be supported. This specification defines a single common type, DAV:basicrsr. >>Request PROPFIND /cfgs/FHHE49495 HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxxxx <?xml version="1.0" encoding="utf-8" ?> <D:propfind xmlns:D="DAV:"> <D:prop> <D:rsrtypes/> </D:prop> </D:propfind> >>Response HTTP/1.1 207 Multi-Status Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>http://www.foobar.com/cfgs/FHHE49495</D:href> <D:propstat> <D:prop> <D:rsrtypes> <D:basicrsr/> </D:rsrtypes> Kaler, et. al. [Page 35]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 </D:prop> </D:propstat> </D:response> </D:multistatus> Clients establish a selection criteria by setting the DAV:selectionrule property. Once set, the dynamic configuration collection contains references to the matching resources. >>Request PROPPATCH /cfgs/FHHE49495 HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxxxx <?xml version="1.0" encoding="utf-8" ?> <D:propertyupdate xmlns:D="DAV:"> <D:set> <D:prop> <D:selectionrule> <D:basicdynamicconfig> ... </D:basicdynamicconfig> </D:selectionrule> </D:prop> </D:set> </D:propertyupdate> The DAV:basicrsr tag groups the selection criteria that are used to populate the dynamic configuration. The selection criteria is specified as a set of tags where nesting represents the expressional ordering. The following tags are available: - DAV:and - The included tags MUST all be true to select - DAV:or - Any of the included tags MUST be true to select - DAV:not - The include tag should be inverted (logically) - DAV:href - The resource URL MUST be the included URL - DAV:label - A revision MUST have the specified label - DAV:tip - The "tip" revision is selected - DAV:revisionid - The specified revision is selected - DAV:configurationid - The configuration MUST be the specified value - DAV:branchid - The branch MUST be the specified value - DAV:depth - Used with DAV:href to indicate a recursive match Kaler, et. al. [Page 36]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 TBD - provide full DTD The following example illustrates a selection rule that includes all revisions in the /Foo/Bar folder (and below) that have been labeled as "Beta1". <?xml version="1.0" encoding="utf-8" ?> <D:basicrsr xmlns:D="DAV:"> <D:and> <D:href>http:/www.foobar.com/Foo/Bar/<D:depth>infinity</D:depth>< /D:href> <D:label>Beta1</D:label> </D:and> </D:basicrsr> 9. WORKSPACE CONFIGURATIONS Branching provides a mechanism for parallel changes to a resource. A workspace configuration is a mechanism for parallel changes of multiple resources. For example, /MySite/ might contain all of the Web pages for V1 of my companies e-commerce site. These have been put in the V1 workspace. A team responsible for developing V2 of the site would create a new workspace configuration based on V1. The V2 workspace is populated with the V1 versions, but these resources can be versioned independently. Essentially all resources have been "branched" in a coordinated fashion. Since this is a branch, both the V1 and the V2 revisions refer to the same versioned resource. This allows history and reports to be generated across workspaces. 9.1. Managing Configuration Content Clients need to be able to access and manage the contents of a configuration. This is done using several different DAV methods. The COPY method can be used to copy a specific revision of a resource. However, this results in a new versioned resource being created. Resources are added to and removed from workspace configurations using the MKREF and DELREF methods defined by the DAV Advanced Collections Working Group. Note that direct references are required. Clients can obtain the contents of a configuration using PROPFIND to enumerate the hierarchy under the configuation's collection. As well, as stated above, clients can use the Configuration-Id header as described previously. Kaler, et. al. [Page 37]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 9.2. Default Workspace Configurations Clients can establish a default workspace configuration that is to be used, for all clients, if they do not specify a workspace configuration. To do this, use the SETDEFAULT method against the configuration root identifying the default configuration. >>Request SETDEFAULT /cfgs/ HTTP/1.1 Host: www.foobar.com Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:setdefault xmlns:D="DAV:"> <D:href>http://www.foobar.com/cfgs/CHFH49594/</D:href> </D:setdefault> >>Response HTTP/1.1 200 OK Content-Length: 0 10. CHECKIN SETS Clients may desire the ability to track a set of changes as a unit. That is, create a grouping of related changes. This is achieved using the MKCHECKINSET method to create a special collection. Clients refer to the checkin set on all checkin (or change) requests. The server automatically creates a "share" to the newly created revision in the identified collection. Checkin sets are specific to a configuration and are created using the MKCHECKINSET method. The DAV:checkinsetroot property on a configuration specifies the URL of a collection where checkin sets for the configuration exist. This can be used for discovery or creation. If a configuration doesn't support checkin sets, then this property will be empty. Clients create checkin sets using MKCHECKINSET. The response includes the location of the new checkin set. >>Request MKCHECKINSET /cs/244 HTTP/1.1 Host: www.foobar.com Content-Length: 0 >>Response HTTP/1.1 201 CREATED Host: www.foobar.com Location: http://www.foobar.com/cs/244 Kaler, et. al. [Page 38]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Content-Length: 0 The following example illustrates use of checkin sets. >>Request CHECKIN /foo/bar HTTP/1.1 Host: www.foobar.com Lock-Token: <opaquelocktoken:rejrei-43343-rereffre> Checkin-Set: /cs/244 Content-Type: text/html Content-Length: xxxx <D:checkin> ... </D:checkin> The following properties MUST be supported on all checkin set collections: DAV:closed - This is a true (1) / false (0) property that indicates if this checkin set can be referenced in CHECKIN requests. When a checkin set is created, this property is defaulted to 0. Note that resources MAY choose to disallow clients from setting this property to 0 once a client has set it to 1. The following properties MUST be supported on all resources: DAV:checkinid - This read-only property returns the checkin id associated with this revision of the resource. A checkin that references a checkin set MUST be made to the configuration associated with the checkin set. 11. VERSION MAPPING This specification defines headers to specify configurations and resource versions. However, there are times when clients require a single URI for when working against configurations or versions. Version mapping support allows servers to create namespaces that map to configurations and versions. Note that mappings are dynamic. That is, as resources are added, removed, and modified, the changes are reflected in any active maps. To delete a mapping, use DELETE against the URI specified in the MKMAP request. Kaler, et. al. [Page 39]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 11.1. Discovery Mapping support is optional and support is discovered using OPTIONS to verify if the MKMAP method is supported. Using the request body and the DAV:verinfo tag, clients can obtain the supported map styles. This example shows that the /cfgs/DFEE2034 configuration supports mapping to the /map/ root in the namespace. >> Request OPTIONS /cfgs/DFEE2034 HTTP/1.1 Host: foobar.com Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:options xmlns:D="DAV:"> <D:verinfo/> </D:options> >> Response HTTP/1.1 200 OK Date: Tue, 20 Jan 1998 20:52:29 GMT Connection: close Accept-Ranges: none Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Public: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MKREF, FREEZE, THAW, CHECKIN, CHECKOUT, UNCHECKOUT, BRANCH Versioning: DAV:versioning Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:options xmlns:D="DAV:"> <D:verinfo> <D:mapstyles> <D:mapstyle>DAV:detailedmap </D:mapstyle> <D:mapstyle>DAV:branchmap </D:mapstyle> <D:mapstyle>DAV:nestedbranch </D:mapstyle> </D:mapstyles> </D:verinfo> </D:options> Kaler, et. al. [Page 40]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 11.2. Mapping Configurations The MKMAP method is used to create namespaces based on a configuration. When a configuration is mapped to a new namespace, all elements within the configuration can be directly accessed within the namespace without requiring the configuration to be identified in the header. In the example below, a new namespace is created for accessing the contents of the /cfgs/DFEE2034 configuration. >> Request MKMAP /maps/mymap HTTP/1.1 Host: foobar.com Configuration-Id: /cfgs/DFEE2034 Content-Type: text/xml Content-Length: xxxx <?xml version="1.0" encoding="utf-8" ?> <D:configurationmap xmlns:D="DAV:"/> >> Response HTTP/1.1 201 CREATED Context-Length: 0 11.3. Mapping Resource Versions The MKMAP method is also used to create namespaces based on a resource's versions (i.e., its revision graph). When a resource is mapped, its revision history (revision graph) within the configuration is made available without requiring the Revision-Id header. Within the mapped namespace, a hierarchy is created for the revisions. However, there are different ways to map the history. Consider the following revision history of the versioned resource bar.htm: V1 -> V2 -> V3 (primary branch) | +-> V1.1 -> V1.2 ("test" branch) The following diagrams illustrate possible mappings: (DAV:detailedmap) (DAV:branchmap) (DAV:nestedbranchmap) V1 Primary Test Primary | | | | +----+--------+ V1 V1.1 +------ Test Kaler, et. al. [Page 41]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 | | | | | | | V2 bar.htm V1.1 V2 V1.2 V1 V1.1 | | | | | +----+ +-----+ V3 V2 V1.2 | | | | | V3 bar.htm V1.2 bar.htm V3 | | bar.htm bar.htm In the example below, a new namespace is created for accessing the versions of the /foo/bar.htm resource in the /cfgs/DFEE2034 configuration. >> Request MKMAP /maps/mymap2 HTTP/1.1 Host: foobar.com Configuration-Id: /cfgs/DFEE2034 Content-Type: text/xml Content-Length: xxx <?xml version="1.0" encoding="utf-8" ?> <D:revisionmap xmlns:D="DAV:"> <D:href>/foo/bar.htm</D:href> <D:mapstyle>DAV:detailedmap</D:mapstyle> </D:revisionmap> >> Response HTTP/1.1 201 CREATED Context-Length: 0 Note that resources MAY support any mapping styles, however, if they support MKMAP, then it MUST support DAV:detailedmap as illustrated above. 12. THE DAV VERSIONING GRAMMAR To be supplied - Describe and detail the DTDs 13. INTERNATIONALIZATION CONSIDERATIONS To be supplied. Kaler, et. al. [Page 42]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 14. SECURITY CONSIDERATIONS To be supplied. 15. SCALABILITY To be supplied. 16. AUTHENTICATION Authentication mechanisms defined in WebDAV will also apply to DAV Versioning. 17. IANA CONSIDERATIONS This document uses the namespace defined by [WebDAV] for XML elements. All other IANA considerations mentioned in [WebDAV] also applicable to DAV Versioning. 18. COPYRIGHT To be supplied. 19. INTELLECTUAL PROPERTY To be supplied. 20. REFERENCES [DAVVERREQ] TBD, "Requirements for DAV Versioning and Variant Authoring", October 1998, internet-draft, work-in-progress, draft- ietf-webdav-versionreqs-00.txt [Kaler] C. Kaler, "Versioning Extensions for WebDAV", September 1998, internet-draft, work-in-progress, draft-kaler-webdav- versioning-00. [RFC2068] R. Fielding, J. Gettys, J. C. Mogul, H. Frystyk, and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2068, U.C. Irvine, DEC, MIT/LCS, January 1997. [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels." RFC 2119, BCP 14. Harvard University. March, 1997. [WebDAV] Y. Goland, E.J. Whitehead, A. Faizi, S.R. Carter, D. Jenson, "Extensions for Distributed Authoring on the World Wide Kaler, et. al. [Page 43]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 Web", April. 1998, internet-draft, work-in-progress, draft-ietf- webdav-protocol-08. [White] E.J. Whitehead, "A Web Versioning Protocol", June 1998, internet-draft, work-in-progress, draft-whitehead-webdav- versioning-00. 21. AUTHOR'S ADDRESSES Christopher Kaler, Editor Microsoft One Microsoft Way Redmond WA, 9085-6933 Email:ckaler@microsoft.com Jim Amsden IBM Email: jamsden@us.ibm.com Geoff Clemm Rational Email: gclemm@atria.com Bruce Cragun Novell Inc. 1555 N. Technology Way Orem, UT 84097 Email: bcragun@novell.com David Durand Email: dgd@cs.bu.edu Bradley Sergeant MicroFocus Email: bradley_sergeant@intersolv.com E. James Whitehead, Jr. Dept. of Information and Computer Science University of California, Irvine Irvine, CA 92697-3425 Email: ejw@ics.uci.edu 22. OPEN ISSUES The following list identifies key open issues against this document: . Can you checkout a collection? What does it mean? . What tags do we want to use for resource/configuration report results? Kaler, et. al. [Page 44]
INTERNET-DRAFT WebDAV Versioning January 20, 1999 . What structure do we create for maps? . What additional resource branching support is needed? . Schema discovery is an issue. For example, how to discover/change mutable/immutable properties? . There are several missing examples / replies that need to be specified. 23. CHANGE HISTORY Sep 28, 1998 Initial Draft based on [White] and [Kaler]. Oct 24, 1998 Incorporate feedback from October 01-02 working group meeting. Jan 20, 1999 Incorporate feedback from December 1998 working group meeting. Kaler, et. al. [Page 45]
