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[[Category:XMPP扩展]]
[[Category:翻译中]]


'''本文的英文原文来自[http://xmpp.org/extensions/xep-0004.html XEP-0004]'''

'''XEP-0004: 数据表单'''

摘要: 本文定义了一个XMPP扩展协议用于数据表单，可以用于worklows如服务配置以及特定应用的数据描述和报告。这个协议包括表单处理的轻量级语义(如请求,响应,提交和取消),定义了几种常见的字段类型(布尔、单个或多个选择的列表选项、单行或多行的文本,单个或多个JabberID、隐藏字段,等等),为以后的数据类型提供扩展性,可以用在广泛的应用中。该协议并不是要提供完整的表格处理功能（由W3C XForms技术提供），而是提供这种功能的基本子集给XMPP使用。

作者:	Ryan Eatmon, Joe Hildebrand, Jeremie Miller, Thomas Muldowney, Peter Saint-Andre

XMPP扩展协议的版权(1999-2008)归XMPP标准化基金会(XSF)所有

版权:	© 1999 - 2010 XMPP标准化基金会(XSF). 参见[[XEP-0004#法律通告|法律通告]].

状态: 最终

类型: 标准跟踪

版本: 2.9

最后更新日期: 2007-08-13

注意: 这里定义的协议是XMPP标准化基金会的一个最终标准.对于实现和布署来说可以被认为是一个稳定技术.

==绪论==

几个现有的Jabber/XMPP的协议包含用户和应用程序之间的结构数据交换，为常用的任务，如注册（[http://xmpp.org/extensions/xep-0077.html In-Band Registration][[XEP-0004#附录G:备注|1]]）和搜索（[http://xmpp.org/extensions/xep-0055.html Jabber Search] [[XEP-0004#附录G:备注|2]]）。不幸的是，这些早期的协议是“硬编码”，因此很大的限制了可交换信息的范围。此外，其他协议(如，[http://xmpp.org/extensions/xep-0045.html Multi-User Chat] [[XEP-0004#附录G:备注|3]])可能需要以交换数据为目的，例如配置，但是配置选项可能根据具体实施或部署不同。最后，开发人员可能要以灵活的方式扩展其他协议(如, [http://xmpp.org/extensions/xep-0030.html Service Discovery][[XEP-0004#附录G:备注|4]])，以提供在基本协议没有定义的信息。在所有这些情况下，这将有助于使用一个通用的数据描述格式，可以用于动态表单生成和各种情况下的数据“建模”。

一个例子可能会有帮助。试想一下，当用户创建一个文本会议服务的多用户聊天室，该服务允许用户以各种方式配置房间。虽然大多数实现可能提供了一个较为常见的可配置功能集（讨论记录，房间拥有者的最大数量，等等）。还会有一些分歧：也许一个实现允许把房间日志以各种文件类型（XML，HTML，PDF等格式）和各种时间周期（每小时，每天，每周等）保存。而另一个实现，可能只存在登录的开/关选择一种格式（如，在HTML保存每日日志）。很明显，第一个实现比第二个实现有更多的配置选项。而不像“硬编码”每个选项通过不同的XML元素（如，<room_logging_period/>），一个好的设计应该包含更多灵活的格式。

此处所描述的'jabber:x:data'协议为Jabber/XMPP实体的使用定义了灵活的格式，控制在“名称值”对的简单和[http://www.w3.org/TR/xforms/ XForms 1.0] [[XEP-0004#附录G:备注|5]]（当这个协议被设计时才开始发展的）的复杂之间。在很多方面，'jabber:x:data' 与[http://www.w3.org/TR/xhtml1/ XHTML 1.0][[XEP-0004#附录G:备注|6]]的表单模块类似。但它提供一些Jabber特有的数据类型，允许应用程序请求数据字段，更自然地集成到IQ节的“workflow”语义中。而且它可以作为现有的Jabber/XMPP协议的扩展，而当这个协议被开发出来时，XHTML的表单模块却不能（尤其是当时并没有[http://www.w3.org/TR/2004/WD-xhtml-modularization-20040218/ Modularization of XHTML] [[XEP-0004#附录G:备注|7]]）。

==需求==

本文档涉及下列需求:

# '''数据收集''' -- 该协议应允许表单处理实体（通常是一个服务器，服务，或bot）从表单提交实体（通常是一个由用户控制的客户端）收集数据。应该是通过不同的数据字段来做，每个都可以是不同的数据“类型”，而且允许自由格式的输入或多个选项的选择（就像HTML表单一样）。
# '''数据报告''' -- 该协议应允许表单处理的实体向表单提交的实体报告数据，再通过不同的数据字段。 
# '''可移植性''' -- 协议应该尽量只定义普通数据格式和基本的数据类型。提示应该在相关的用户界面提供，但应该仅仅是提示，而不是严格的要求。 
# '''简单''' -- 协议在客户端的实施应该简单，并且大多数复杂的工作（如，数据有效性和处理）应由服务器和组件去完成，而不是客户端。 
# '''灵活性''' -- 协议应该具有灵活性和可扩展性，而不像“硬编码”。
# '''兼容性''' -- 协议应该为已有的Jabber/XMPP协议定义一个扩展，而且不破坏已有的实现，除非绝对必要。

==协议==

'jabber:x:data' 命名空间的基本语法如下（正式的描述可以在下面的XML节中找到）:

<source lang="xml">
<x xmlns='jabber:x:data' 
   type='{form-type}'> 
  <title/> 
  <instructions/> 
  <field var='field-name' 
         type='{field-type}' 
         label='description'> 
    <desc/> 
    <required/> 
    <value>field-value</value> 
    <option label='option-label'><value>option-value</value></option> 
    <option label='option-label'><value>option-value</value></option> 
  </field> 
</x> 
</source>

受'jabber:x:data' 命名空间限制的<x/>元素，应该包括直接作为<message/>节第一级子元素或作为<iq/> 节（其中第一级子元素是由一个"wrapper"命名空间限制的）的第二级子节。参见下文列举的限制。

可选项<title/>和<instructions/>元素，允许表单处理实体把表单标记为一个整体并指定自然语言指令，后面跟着表单提交实体。这些元素的XML字符数据不应包含换行符（\n和\r字符），而任何换行符操作（如，在用户界面显示）在这里不是特指的。但<instructions/>元素的多个实体可以被包括在内。

===表单类型===

'jabber:x:data'表单中数据的收集或提供可以位于不同的上下文。例子包括一个需要填写的空表单，填好的表单，一个提交结果，一个搜索结果，或仅仅是用'jabber:x:data'命名空间封装的一组数据。完整的数据上下文由3个条件提供：

# "wrapper"协议（即，以<iq/>节直接子元素为根元素的命名空间和受'jabber:x:data' 命名空间限制的<x/>元素的父元素）。
# 一个包含事务（如，一个IQ "set"或"result"）或会话结构（如，一个消息<thread/>）的表单的位置。
# 表单中<x/>根元素的类型属性

前面2件上下文信息有其他协议提供，而表单类型见下表描述。

:'''表1：表单类型'''

{|border="1" cellspacing="0" 
! 类型 !! 描述
|-
|表单 || 表单处理实体请求表单提交实体去完成表单。
|-
|提交 || 表单提交实体提交数据给表单处理实体。提交信息可以包含不是空表单提供的字段，但表单处理实体必须忽略任何无法识别的字段。
|-
|取消 || 表单提交实体取消给表单处理实体提交的数据。
|-
|结果 || 单处理实体返回数据（如查询结果）给表单提交实体，或数据是一个通用的数据集。
|}




为了维护表单类型中获取的数据的上下文，必须遵守以下规则:

:* 对于<iq/>节，受"wrapper" 命名空间限制的根元素，以"form" 或"submit"的一种形式，必须以一种"result"形式的表单返回。受'jabber:x:data'命名空间限制的<x/>元素，必须是"wrapper"命名空间根元素的子元素。根据XMPP Core [8]所定义， 'id' 属性必须在IQ结果中被复制。对于表单类型为"form" 或 "result",<iq/>节应该是"result"类型。对于表单类型为"submit" 或"cancel"，  <iq/>节应该是"set"类型。

:* 对于<message/>节，如果提供的话，<thread/>应该在回复中被复制。受'jabber:x:data'命名空间限制的<x/>元素，必须是<message/>节的子元素。

===字段元素===

一个"form"，"submit"，或 "result"类型的数据表单应该包含至少一个<field/>元素。一个"cancel"类型的表单，不应该包含任何<field/>元素。


<field/>元素可以包含以下任何子元素:

:'''<desc/>'''
:该元素的XML字符数据提供了该字段一个自然语言的描述，为了在用户代理中介绍（如，作为一个"tool-tip"，帮助按钮，或在字段附近的文本标记）。<desc/>元素不应包含换行符（\n和\r字符），因为布局负责用户代理，任何换行的处理（如，在用户界面演示）在这里是未指明的。（注意：提供一个字段的描述，使用<desc/>元素是被推荐的，而不是一个单独的"fixed"类型的<field/>元素。）
 
:'''<required/>'''
:该元素必须为空，标记所需的字段，为了被表单识别为有效字段。
 
:'''<value/>'''
:该元素的XML字符数据定义了在"form"类型数据表单中的字段（根据表单处理实体）的默认值，在"submit"类型数据表单中由表单提交实体提供的数据，或在"result"类型数据表单中的数据结果。在"form"类型数据表单中，如果表单处理实体通过<value/>元素提供了一个默认值，表单提交实体就不应该尝试去执行一个不同的默认值。
 
:'''<option/>'''
:在"list-single"或"list-multi"字段类型中的一个选项。<value/>子元素的XML字符定义了选项的值，而且标签属性为选项定义了一个人们易读的名称。<option/>元素必须且只能包含一个<value/>子元素。如果字段类型不是"list-single"或"list-multi"，就一定不能包含<option/>元素。
 
如果<field/>元素类型是其他的而不是“fixed”（见下文），它必须拥有一个'var'属性在表单中唯一标识字段（如果是“fixed”，可以拥有一个'var'属性）。<field/>元素可以拥有一个标签属性，为字段定义一个人们易读的名称。对于“form”类型的数据表单，每个<field/>元素应该拥有'type'属性，它定义了字段数据的数据 "type"（如果没有'type'被指定，则默认为"text-single"）。在其他表单类型的上下文中提供的字段，也可以拥有一个'type'属性。对于"submit"类型的数据表单，'type'中包含的属性是可选的，因为表单处理实体被假定知道它处理的表单的数据类型。

如果字段出现在用户页面上（如，问卷中的项或表单结果），在XML中的字段元素的顺序，应该决定出现在用户处的项目的顺序。

===字段类型===
The following field types represent data "types" that are commonly exchanged between Jabber/XMPP entities. These field types are not intended to be as comprehensive as the datatypes defined in, for example, XML Schema Part 2 [9], nor do they define user interface elements.

Table 2: Field Types

Type Description 
boolean The field enables an entity to gather or provide an either-or choice between two options. The default value is "false". [10] 
fixed The field is intended for data description (e.g., human-readable text such as "section" headers) rather than data gathering or provision. The <value/> child SHOULD NOT contain newlines (the \n and \r characters); instead an application SHOULD generate multiple fixed fields, each with one <value/> child. 
hidden The field is not shown to the form-submitting entity, but instead is returned with the form. The form-submitting entity SHOULD NOT modify the value of a hidden field, but MAY do so if such behavior is defined for the "using protocol". 
jid-multi The field enables an entity to gather or provide multiple Jabber IDs. Each provided JID SHOULD be unique (as determined by comparison that includes application of the Nodeprep, Nameprep, and Resourceprep profiles of Stringprep as specified in XMPP Core), and duplicate JIDs MUST be ignored. * 
jid-single The field enables an entity to gather or provide a single Jabber ID. * 
list-multi The field enables an entity to gather or provide one or more options from among many. A form-submitting entity chooses one or more items from among the options presented by the form-processing entity and MUST NOT insert new options. The form-submitting entity MUST NOT modify the order of items as received from the form-processing entity, since the order of items MAY be significant.** 
list-single The field enables an entity to gather or provide one option from among many. A form-submitting entity chooses one item from among the options presented by the form-processing entity and MUST NOT insert new options. ** 
text-multi The field enables an entity to gather or provide multiple lines of text. *** 
text-private The field enables an entity to gather or provide a single line or word of text, which shall be obscured in an interface (e.g., with multiple instances of the asterisk character). 
text-single The field enables an entity to gather or provide a single line or word of text, which may be shown in an interface. This field type is the default and MUST be assumed if a form-submitting entity receives a field type it does not understand. 

* Note: Data provided for fields of type "jid-single" or "jid-multi" MUST contain one or more valid Jabber IDs, where validity is determined by the addressing rules defined in XMPP Core (see the Data Validation section below).

** Note: The <option/> elements in list-multi and list-single fields MUST be unique, where uniqueness is determined by the value of the 'label' attribute and the XML character data of the <value/> element (i.e., both must be unique).

*** Note: Data provided for fields of type "text-multi" SHOULD NOT contain any newlines (the \n and \r characters). Instead, the application SHOULD split the data into multiple strings (based on the newlines inserted by the platform), then specify each string as the XML character data of a distinct <value/> element. Similarly, an application that receives multiple <value/> elements for a field of type "text-multi" SHOULD merge the XML character data of the value elements into one text block for presentation to a user, with each string separated by a newline character as appropriate for that platform.

===表单结果中的多个项目===
In some contexts (e.g., the results of a search request), it may be necessary to communicate multiple items. Therefore, a data form of type "result" MAY contain two child elements not described in the basic syntax above:

One and only <reported/> element, which can be understood as a "table header" describing the data to follow. 
Zero or more <item/> elements, which can be understood as "table cells" containing data (if any) that matches the request. 
The syntax is as follows:


<x xmlns='jabber:x:data' 
   type='result'> 
  <reported> 
    <field var='field-name' label='description' type='{field-type}'/> 
  </reported> 
  <item> 
    <field var='field-name'> 
      <value>field-value</value> 
    </field> 
  </item> 
  <item> 
    <field var='field-name'> 
      <value>field-value</value> 
    </field> 
  </item> 
  . 
  . 
  . 
</x> 
    Each of these elements MUST contain one or more <field/> children. The <reported/> element defines the data format for the result items by specifying the fields to be expected for each item; for this reason, the <field/> elements SHOULD possess a 'type' attribute and 'label' attribute in addition to the 'var' attribute, and SHOULD NOT contain a <value/> element. Each <item/> element defines one item in the result set, and MUST contain each field specified in the <reported/> element (although the XML character data of the <value/> element MAY be null).

==数据有效性==

Data validation is the responsibility of the form-processing entity (commonly a server, service, or bot) rather than the form-submitting entity (commonly a client controlled by a human user). This helps to meet the requirement for keeping client implementations simple. If the form-processing entity determines that the data provided is not valid, it SHOULD return a "Not Acceptable" error, optionally providing a textual explanation in the XMPP <text/> element or an application-specific child element that identifies the problem (see Error Condition Mappings [11] for information about mappings and formats).

==例子==

For the sake of the following examples, let us suppose that there exists a bot hosting service on the Jabber network, located at <botster.shakespeare.lit>. This service enables registered users to create and configure new bots, find and interact with existing bots, and so on. We will assume that these interactions occur using the Ad-Hoc Commands [12] protocol, which is used as a "wrapper" protocol for data forms qualified by the 'jabber:x:data' namespace. The examples in the sections that follow show most of the features of the data forms protocol described above.

Note: Additional examples can be found in the specifications for various "using protocols", such as XEP-0045: Multi-User Chat and XEP-0055: Jabber Search.

===配置===

The first step is for a user to create a new bot on the hosting service. We will assume that this is done by sending a "create" command to the desired bot:

Example 1. User Requests Bot Creation

<iq from='romeo@montague.net/home' 
    to='joogle@botster.shakespeare.lit' 
    type='get' 
    xml:lang='en' 
    id='create1'> 
  <command xmlns='http://jabber.org/protocol/commands'  
           node='create' 
           action='execute'/> 
</iq> 
    The hosting service then returns a data form to the user:

Example 2. Service Returns Bot Creation Form

<iq from='joogle@botster.shakespeare.lit' 
    to='romeo@montague.net/home' 
    type='result' 
    xml:lang='en' 
    id='create1'> 
  <command xmlns='http://jabber.org/protocol/commands' 
           node='create' 
           sessionid='create:20040408T0128Z' 
           status='executing'> 
    <x xmlns='jabber:x:data' type='form'> 
      <title>Bot Configuration</title> 
      <instructions>Fill out this form to configure your new bot!</instructions> 
      <field type='hidden' 
             var='FORM_TYPE'> 
        <value>jabber:bot</value> 
      </field> 
      <field type='fixed'><value>Section 1: Bot Info</value></field> 
      <field type='text-single' 
             label='The name of your bot' 
             var='botname'/> 
      <field type='text-multi' 
             label='Helpful description of your bot' 
             var='description'/> 
      <field type='boolean' 
             label='Public bot?' 
             var='public'> 
        <required/> 
      </field> 
      <field type='text-private' 
             label='Password for special access' 
             var='password'/> 
      <field type='fixed'><value>Section 2: Features</value></field> 
      <field type='list-multi' 
             label='What features will the bot support?' 
             var='features'> 
        <option label='Contests'><value>contests</value></option> 
        <option label='News'><value>news</value></option> 
        <option label='Polls'><value>polls</value></option> 
        <option label='Reminders'><value>reminders</value></option> 
        <option label='Search'><value>search</value></option> 
        <value>news</value> 
        <value>search</value> 
      </field> 
      <field type='fixed'><value>Section 3: Subscriber List</value></field> 
      <field type='list-single' 
             label='Maximum number of subscribers' 
             var='maxsubs'> 
        <value>20</value> 
        <option label='10'><value>10</value></option> 
        <option label='20'><value>20</value></option> 
        <option label='30'><value>30</value></option> 
        <option label='50'><value>50</value></option> 
        <option label='100'><value>100</value></option> 
        <option label='None'><value>none</value></option> 
      </field> 
      <field type='fixed'><value>Section 4: Invitations</value></field> 
      <field type='jid-multi' 
             label='People to invite' 
             var='invitelist'> 
        <desc>Tell all your friends about your new bot!</desc> 
      </field> 
    </x> 
  </command> 
</iq> 
    The user then submits the configuration form:

Example 3. User Submits Bot Creation Form

<iq from='romeo@montague.net/home' 
    to='joogle@botster.shakespeare.lit' 
    type='set' 
    xml:lang='en' 
    id='create2'> 
  <command xmlns='http://jabber.org/protocol/commands' 
           node='create' 
           sessionid='create:20040408T0128Z'> 
    <x xmlns='jabber:x:data' type='submit'> 
      <field type='hidden' var='FORM_TYPE'> 
        <value>jabber:bot</value> 
      </field> 
      <field type='text-single' var='botname'> 
        <value>The Jabber Google Bot</value> 
      </field> 
      <field type='text-multi' var='description'> 
        <value>This bot enables you to send requests to</value> 
        <value>Google and receive the search results right</value> 
        <value>in your Jabber client. It&apos; really cool!</value> 
        <value>It even supports Google News!</value> 
      </field> 
      <field type='boolean' var='public'> 
        <value>0</value> 
      </field> 
      <field type='text-private' var='password'> 
        <value>v3r0na</value> 
      </field> 
      <field type='list-multi' var='features'> 
        <value>news</value> 
        <value>search</value> 
      </field> 
      <field type='list-single' var='maxsubs'> 
        <value>50</value> 
      </field> 
      <field type='jid-multi' var='invitelist'> 
        <value>juliet@capulet.com</value> 
        <value>benvolio@montague.net</value> 
      </field> 
    </x> 
  </command> 
</iq> 
    The service then returns the results to the user:

Example 4. Service Returns Bot Creation Result

<iq from='joogle@botster.shakespeare.lit' 
    to='romeo@montague.net/home' 
    type='result' 
    xml:lang='en' 
    id='create2'> 
  <command xmlns='http://jabber.org/protocol/commands' 
           node='create' 
           sessionid='create:20040408T0128Z' 
           status='completed'> 
    <x xmlns='jabber:x:data' type='result'> 
      <field type='hidden' var='FORM_TYPE'> 
        <value>jabber:bot</value> 
      </field> 
      <field type='text-single' var='botname'> 
        <value>The Jabber Google Bot</value> 
      </field> 
      <field type='boolean' var='public'> 
        <value>0</value> 
      </field> 
      <field type='text-private' var='password'> 
        <value>v3r0na</value> 
      </field> 
      <field type='list-multi' var='features'> 
        <value>news</value> 
        <value>search</value> 
      </field> 
      <field type='list-single' var='maxsubs'> 
        <value>50</value> 
      </field> 
      <field type='jid-multi' var='invitelist'> 
        <value>juliet@capulet.com</value> 
        <value>benvolio@montague.net</value> 
      </field> 
    </x> 
  </command> 
</iq> 
    
===搜索===

Now that the user has created this search bot, let us suppose that one of the friends he has invited decides to try it out by sending a search request:

Example 5. User Requests Search Form

<iq from='juliet@capulet.com/chamber' 
    to='joogle@botster.shakespeare.lit' 
    type='get' 
    xml:lang='en' 
    id='search1'> 
  <command xmlns='http://jabber.org/protocol/commands'  
           node='search' 
           action='execute'/> 
</iq> 
    Example 6. Service Returns Search Form

<iq from='joogle@botster.shakespeare.lit' 
    to='juliet@capulet.com/chamber' 
    type='result' 
    xml:lang='en' 
    id='search1'> 
  <command xmlns='http://jabber.org/protocol/commands'  
           node='search' 
           status='executing'> 
    <x xmlns='jabber:x:data' type='form'> 
      <title>Joogle Search</title> 
      <instructions>Fill out this form to search for information!</instructions> 
      <field type='text-single' 
             var='search_request'> 
        <required/> 
      </field> 
    </x> 
  </command> 
</iq> 
    Example 7. User Submits Search Form

<iq from='juliet@capulet.com/chamber' 
    to='joogle@botster.shakespeare.lit' 
    type='get' 
    xml:lang='en' 
    id='search2'> 
  <command xmlns='http://jabber.org/protocol/commands'  
           node='search'> 
    <x xmlns='jabber:x:data' type='submit'> 
      <field type='text-single' var='search_request'> 
        <value>verona</value> 
      </field> 
    </x> 
  </command> 
</iq> 
    Example 8. Service Returns Search Results

<iq from='joogle@botster.shakespeare.lit' 
    to='juliet@capulet.com/chamber' 
    type='result' 
    xml:lang='en' 
    id='search2'> 
  <command xmlns='http://jabber.org/protocol/commands'  
           node='search' 
           status='completed'> 
    <x xmlns='jabber:x:data' type='result'> 
      <title>Joogle Search: verona</title> 
      <reported> 
        <field var='name'/> 
        <field var='url'/> 
      </reported> 
      <item> 
        <field var='name'> 
          <value>Comune di Verona - Benvenuti nel sito ufficiale</value> 
        </field> 
        <field var='url'> 
          <value>http://www.comune.verona.it/</value> 
        </field> 
      </item> 
      <item> 
        <field var='name'> 
          <value>benvenuto!</value> 
        </field> 
        <field var='url'> 
          <value>http://www.hellasverona.it/</value> 
        </field> 
      </item> 
      <item> 
        <field var='name'> 
          <value>Universita degli Studi di Verona - Home Page</value> 
        </field> 
        <field var='url'> 
          <value>http://www.univr.it/</value> 
        </field> 
      </item> 
      <item> 
        <field var='name'> 
          <value>Aeroporti del Garda</value> 
        </field> 
        <field var='url'> 
          <value>http://www.aeroportoverona.it/</value> 
        </field> 
      </item> 
      <item> 
        <field var='name'> 
          <value>Veronafiere - fiera di Verona</value> 
        </field> 
        <field var='url'> 
          <value>http://www.veronafiere.it/</value> 
        </field> 
      </item> 
    </x> 
  </command> 
</iq> 
  
==服务发现==

If an entity supports inclusion of the <x/> element qualified by the 'jabber:x:data' namespace as a direct child of the <message/> stanza type, it MUST report support by including a service discovery feature of "jabber:x:data" (see Protocol Namespaces regarding issuance of one or more permanent namespaces) in response to a Service Discovery information request:

Example 9. Service Discovery information request

<iq type='get' 
    from='romeo@montague.net/orchard' 
    to='juliet@capulet.com/balcony' 
    id='disco1'> 
  <query xmlns='http://jabber.org/protocol/disco#info'/> 
</iq> 
  Example 10. Service Discovery information response

<iq type='result' 
    from='juliet@capulet.com/balcony' 
    to='romeo@montague.net/orchard' 
    id='disco1'> 
  <query xmlns='http://jabber.org/protocol/disco#info'> 
    ... 
    <feature var='jabber:x:data'/> 
    ... 
  </query> 
</iq> 
  If an entity supports data forms indirectly through inclusion of data forms in a wrapper namespace (rather than directly within a <message/> stanza), it MUST NOT advertise support for the 'jabber:x:data' namespace, since support is implicit in support for the wrapper protocol.

==安全性考虑==

There are no security concerns related to this specification above and beyond those described in the relevant section of XMPP Core.

==IANA考虑==
This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [13].

==XMPP注册考虑==

===协议命名空间===
The XMPP Registrar [14] includes the 'jabber:x:data' namespace in its registry of protocol namespaces.

===参数值===

The XMPP Registrar maintains a registry of parameter values related to the 'jabber:x:data' namespace, specifically as defined in Field Standardization for Data Forms [15]; the registry is located at <http://xmpp.org/registrar/formtypes.html>.

==XML 架构==

This schema is descriptive, not normative.


<?xml version='1.0' encoding='UTF-8'?> 
 
<xs:schema 
    xmlns:xs='http://www.w3.org/2001/XMLSchema' 
    targetNamespace='jabber:x:data' 
    xmlns='jabber:x:data' 
    elementFormDefault='qualified'> 
 
  <xs:annotation> 
    <xs:documentation> 
      The protocol documented by this schema is defined in 
      XEP-0004: http://www.xmpp.org/extensions/xep-0004.html 
    </xs:documentation> 
  </xs:annotation> 
 
  <xs:element name='x'> 
    <xs:complexType> 
      <xs:sequence> 
        <xs:element name='instructions'  
                    minOccurs='0'  
                    maxOccurs='unbounded'  
                    type='xs:string'/> 
        <xs:element name='title' minOccurs='0' type='xs:string'/> 
        <xs:element ref='field' minOccurs='0' maxOccurs='unbounded'/> 
        <xs:element ref='reported' minOccurs='0' maxOccurs='1'/> 
        <xs:element ref='item' minOccurs='0' maxOccurs='unbounded'/> 
      </xs:sequence> 
      <xs:attribute name='type' use='required'> 
        <xs:simpleType> 
          <xs:restriction base='xs:NCName'> 
            <xs:enumeration value='cancel'/> 
            <xs:enumeration value='form'/> 
            <xs:enumeration value='result'/> 
            <xs:enumeration value='submit'/> 
          </xs:restriction> 
        </xs:simpleType> 
      </xs:attribute> 
    </xs:complexType> 
  </xs:element> 
 
  <xs:element name='field'> 
    <xs:complexType> 
      <xs:sequence> 
        <xs:element name='desc' minOccurs='0' type='xs:string'/> 
        <xs:element name='required' minOccurs='0' type='empty'/> 
        <xs:element ref='value' minOccurs='0' maxOccurs='unbounded'/> 
        <xs:element ref='option' minOccurs='0' maxOccurs='unbounded'/> 
      </xs:sequence> 
      <xs:attribute name='label' type='xs:string' use='optional'/> 
      <xs:attribute name='type' use='optional'> 
        <xs:simpleType> 
          <xs:restriction base='xs:NCName'> 
            <xs:enumeration value='boolean'/> 
            <xs:enumeration value='fixed'/> 
            <xs:enumeration value='hidden'/> 
            <xs:enumeration value='jid-multi'/> 
            <xs:enumeration value='jid-single'/> 
            <xs:enumeration value='list-multi'/> 
            <xs:enumeration value='list-single'/> 
            <xs:enumeration value='text-multi'/> 
            <xs:enumeration value='text-private'/> 
            <xs:enumeration value='text-single'/> 
          </xs:restriction> 
        </xs:simpleType> 
      </xs:attribute> 
      <xs:attribute name='var' type='xs:string' use='optional'/> 
    </xs:complexType> 
  </xs:element> 
 
  <xs:element name='option'> 
    <xs:complexType> 
      <xs:sequence> 
        <xs:element ref='value'/> 
      </xs:sequence> 
      <xs:attribute name='label' type='xs:string' use='optional'/> 
    </xs:complexType> 
  </xs:element> 
 
  <xs:element name='value' type='xs:string'/> 
 
  <xs:element name='reported'> 
    <xs:annotation> 
      <xs:documentation> 
        When contained in a "reported" element, the "field" element 
        SHOULD NOT contain a "value" child. 
      </xs:documentation> 
    </xs:annotation> 
    <xs:complexType> 
      <xs:sequence> 
        <xs:element ref='field' maxOccurs='unbounded'/> 
      </xs:sequence> 
    </xs:complexType> 
  </xs:element> 
 
  <xs:element name='item'> 
    <xs:complexType> 
      <xs:sequence> 
        <xs:element ref='field' maxOccurs='unbounded'/> 
      </xs:sequence> 
    </xs:complexType> 
  </xs:element> 
 
  <xs:simpleType name='empty'> 
    <xs:restriction base='xs:string'> 
      <xs:enumeration value=''/> 
    </xs:restriction> 
  </xs:simpleType> 
 
</xs:schema> 
  11. Changes in Final State
The following substantive protocol changes have been made while this specification has been in the Final state:

Specified that the 'var' attribute is required for all field types except "fixed", for which the 'var' attribute is optional. 
Specified when to advertise support via service discovery. 
Removed references to <presence/> stanzas. 
12. Changes in Draft State
The following substantive protocol changes were made while this specification was in the Draft state:

The <x/> element MAY be included directly in <message/> and <presence/> stanzas. 
The <x/> element MAY contain a <title/> child for forms and results. 
The <x/> element MUST possess a 'type' attribute. 
A <field/> element MAY be of type='jid-single'. 
Results MAY be reported back in <item/> tags. 
Results MAY contain a <reported/> element with result set. 
The <reported/> fields MAY possess a 'type' attribute to provide hints about how to interact with the data (type='jid-single' being the most useful). 

==最终状态的修改==

当本规范已经是最终状态时，下面的实体协议已经做了修改：

* 指定的'var'属性是所有字段类型所必须的，除了"fixed", 因为'var'属性是可选的。

* 通过服务搜索指定何时去通知支持。
  
* 移除引用<presence/>节。

==草稿状态的修改==

当本规范在草稿状态时，下面的实体协议已经做了修改：

* <x/>元素可能直接包含在<message/>和<presence/>节中。
* <x/>元素可能包含一个<title/>子元素，在表单或结果中。
* <x/>元素必须拥有一个‘类型’属性。
* <field/>元素可能是类型='jid-single'。
* 结果可能以<item/>标签的方式返回报告。
* 结果可能包含一个<reported/>元素的结果集。
* <reported/>字段可能拥有一个‘类型’属性，提供如何与数据交互的提示（类型='jid-single'是最有用的）。

==附录==
===附录A:文档信息===

系列：[http://xmpp.org/extensions/ XEP]

序号：0004

发布者：[http://xmpp.org/xsf/ XMPP标准基金会]

状态：[http://www.xmpp.org/extensions/xep-0001.html#states-Final 终结版]

类型：[http://www.xmpp.org/extensions/xep-0001.html#types-Standards%20Track 标准跟踪]

版本：2.9

最后更新：2007-07-13

批准机构：[http://xmpp.org/council/ XMPP理事会]

依赖标准：[[RFC3920|XMPP Core]]

替代标准：无

被替代标准：无

缩略名：x-data

XML架构:<http://www.xmpp.org/schemas/x-data.xsd>

原文控制： [http://svn.xmpp.org:18080/browse/XMPP/trunk/extensions/xep-0004.xml HTML] [http://svn.xmpp.org:18080//changelog/~rss/XMPP/trunk/extensions/xep-0004.xml/rss.xml RSS]

本文的其它格式： [http://xmpp.org/extensions/xep-0004.xml XML] [http://xmpp.org/extensions/xep-0004.pdf PDF]


===附录B:作者信息===

'''Ryan Eatmon'''

Email: [mailto:reatmon@jabber.org reatmon@jabber.org]

JabberID: reatmon@jabber.org


'''Joe Hildebrand'''

Email: [mailto:jhildebr@cisco.com jhildebr@cisco.com]

JabberID: hildjj@jabber.org


'''Jeremie Miller'''

Email: [mailto:jer@jabber.org jer@jabber.org]

JabberID: jer@jabber.org


'''Thomas Muldowney'''

Email: [mailto:temas@jabber.org temas@jabber.org]

JabberID: temas@jabber.org


'''Peter Saint-Andre'''

Email: [mailto:stpeter@jabber.org stpeter@jabber.org]

JabberID: stpeter@jabber.org

URI: https://stpeter.im/

{{Template:XEP附录CDEF}}

===附录G:备注===
#XEP-0077: In-Band Registration <http://xmpp.org/extensions/xep-0077.html>.
#XEP-0055: Jabber Search <http://xmpp.org/extensions/xep-0055.html>.
#XEP-0045: Multi-User Chat <http://xmpp.org/extensions/xep-0045.html>.
#XEP-0030: Service Discovery <http://xmpp.org/extensions/xep-0030.html>.
#XForms 1.0 <http://www.w3.org/TR/xforms>.
#XHTML 1.0 <http://www.w3.org/TR/xhtml1>.
#Modularization of XHTML <http://www.w3.org/TR/2004/WD-xhtml-modularization-20040218/>.
#RFC 3920: Extensible Messaging and Presence Protocol (XMPP): Core <http://tools.ietf.org/html/rfc3920>.
#XML Schema Part 2: Datatypes <http://www.w3.org/TR/xmlschema-2/>.
#In accordance with Section 3.2.2.1 of XML Schema Part 2: Datatypes, the allowable lexical representations for the xs:boolean datatype are the strings "0" and "false" for the concept 'false' and the strings "1" and "true" for the concept 'true'; implementations MUST support both styles of lexical representation.
#XEP-0086: Error Condition Mappings <http://xmpp.org/extensions/xep-0086.html>.
#XEP-0050: Ad-Hoc Commands <http://xmpp.org/extensions/xep-0050.html>.
#The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.
#The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://xmpp.org/registrar/>.
#XEP-0068: Field Data Standardization for Data Forms <http://xmpp.org/extensions/xep-0068.html>.

===附录H:修订历史===

注意: 

'''版本 2.9 (2007-08-13)'''



(psa)

'''版本 2.8 (2007-05-21)'''



(psa)