Type a search term to find related articles by LIMS subject matter experts gathered from the most trusted and dynamic collaboration tools in the laboratory informatics industry.
Filename extension |
.xpl |
---|---|
Internet media type |
application/xproc+xml |
Type of format | Stylesheet language / Scripting language |
Extended from | XML |
Standard | XProc 3.0 |
XProc is an XML transformation language for processing documents in pipelines: chaining conversions and other steps together to achieve the desired results. It can handle documents in XML, HTML, JSON, text and binary.
The current (stable) version is 3.0.[1] While XProc 1.0[2] is a W3C Recommendation, XProc 3.0 is a standard developed by the W3C XProc Next Community Group.[3]
Its main characteristics are:
The following is a (very) simple XProc pipeline:
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:input port="source"/>
<p:output port="result"/>
<p:add-attribute attribute-name="timestamp" attribute-value="{current-dateTime()}"/>
<p:delete match="@data"/>
</p:declare-step>
source
. This is where the original document flows in.result
. This is where the resulting document flows out.source
port automatically flows into the first step of the pipeline. This p:add-attribute
step adds an attribute called timestamp
with the current date and time.p:delete
step that removes all attributes called data
.p:delete
is the last step, the resulting document flows out through the output result
port.So if you supply the following XML document to this pipeline:
<example data="321">
<item data="123">Some data...</item>
</example>
It comes out as:
<example timestamp="2024-09-11T15:05:22.82+02:00">
<item>Some data...</item>
</example>
The exact date and time recorded in the timestamp
attribute is of course dependent on the date and time the pipeline is executed.
The learning page of the XProc website[4] contains links to all the learning and reference materials the XProc community group is aware of. There is a special 101 section with introductory learning materials.
Ideas for something, some programming language, for processing were there right from the beginnings of XML, at the end of the twentieth century. But it was not until the end of 2005 that the W3C started a working group called the XML Processing Model Working Group. this resulted in the recommendation for XProc 1.0 dated May 11, 2010.[2]
There were various attempts to create working XProc 1.0 processors. The only two currently available as open source products that implement the full 1.0 standard are XML Calabash[5] and MorganaXProc.[6]
After the release of version 1.0, the XProc working group continued debating a next version. Ideas were raised for version 2.0. This was based on a non-XML syntax which didn’t raise a lot of support from the community. Engagement in the working grouped waned and in 2016 it ceased to exist.
In June 2017 the XProc Next Community Group[3] was founded and started working on a new version, now completely XML based. Because this was a completely different approach than the 2.0 initiative, the version number was increased to 3.0. A stable version was released on 12 September 2022.[1]
In 2024 the working group started work on a minor update to 3.1.
The following processors support the XProc 3.0 standard:
The following processors support the XProc 1.0 standard. There were several other XProc 1.0 implementations, but these were either incomplete or are not maintained.
This is the logo of XProc. It was created by Bethan Tovey-Walsh. The fish is called Kanava, which is Finnish for pipeline.