p:uuid (3.0) 

Summary

<p:declare-step type="p:uuid">
  <input port="source" primary="true" content-types="xml html" sequence="false"/>
  <output port="result" primary="true" content-types="text xml html" sequence="false"/>
  <option name="match" as="xs:string" required="false" select="'/*'"/>
  <option name="version" as="xs:integer?" required="false" select="()"/>
</p:declare-step>

The p:uuid step takes the document appearing on its source port and replaces nodes matching the match option with a UUID.

Ports:

Options:

Description

UUID stands for Universally Unique Identifier. It is also known as GUID, which stands for Globally Unique Identifier. A UUID is a 128-bit value that is, for all practical purposes, worldwide unique. It is usually written as a 32-character hexadecimal value in a pattern using hyphens, for example f81d4fae-7dec-11d0-a765-00a0c91e6bf6. The Wikipedia page about UUIDs is here.

The p:uuid step does the following:

• It computes a single UUID, using the version option. This UUID is used for all replacements (so all replacements get the same value).

• It takes the document appearing on its source port and holds the XSLT selection pattern in the match option against this.

• For all matched nodes:

  • If the matched node is an attribute, the value of the attribute is replaced with the UUID.

  • If the document-node is matched, the full document will be replaced by UUID (and the result will therefore be a text document).

  • In all other cases, the full node is replaced by the UUID.

Examples

<thing>
   <uuid>UUID</uuid>
   <uuid>UUID</uuid>
</thing>

<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">

  <p:input port="source"/>
  <p:output port="result"/>

  <p:uuid match="/thing/uuid/text()"/>

</p:declare-step>

<thing>
   <uuid>d5c23f1e-36f1-469f-8ac1-959e63050d5b</uuid>
   <uuid>d5c23f1e-36f1-469f-8ac1-959e63050d5b</uuid>
</thing>

<thing uuid=""/>

<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">

  <p:input port="source"/>
  <p:output port="result"/>

  <p:uuid match="/thing/@uuid"/>

</p:declare-step>

<thing uuid="811862e2-942f-4390-b604-7828810ca0a4"/>

Additional details

• p:uuid preserves all document-properties of the document(s) appearing on its source port.

  There is one exception: if the resulting document contains only text, the content-type document-property is changed to text/plain and the serialization document-property is removed.

• If an attribute called xml:base is added or changed, the base URI of the element is updated accordingly. See also category Base URI related.

Errors raised

Reference information

This description of the p:uuid step is for XProc version: 3.0. This is a required step (an XProc 3.0 processor must support this).

The formal specification for the p:uuid step can be found here.

The p:uuid step is part of categories:

• Standard XProc steps

• Basic XML manipulation

• Miscellaneous

The p:uuid step is also present in version: 3.1.