XML hierarchical linear pipeline (XHLP)

XHLP Description

The XML hierarchical linear pipeline (XHLP) is suite of JavaScript functions to enable XML processing with XSLT in the browser.

A XHLP pipeline consists of a list of processing steps, which transform an input XML document to either XML or text. Processing steps are either one of

• a relative URL ending with .xsl: The document will be loaded and an XSLT transformation will be performed
• a relative URL ending with .xml: The document will be loaded, a list of steps will be extracted from it and and a XHLP transformation will be performed (hence the name hierachical)
• any other string will be evaluated with eval, to produce a function, which will be applied
• a function(in, done), which will be applied and which must call done with the result

XHLP is asynchronous and uses callback functions to return the processing result. XHLP is asynchronous because it automatically loads XSL stylesheets and XML pipeline definitions in the background, from a URL prefix that is set for each pipeline.

Input to XHLP can be either parsed XML documents, using transform, or XML markup, which will be parsed on the fly by transformTxt.

XHLP works in all major webbrowsers and can be used to paper over minor differences in the browser implementations of XSLT processing.

XHLP install

Distribute ./js/xlp.js from your server and include it in your HTML content:

<script src="/static/js/xlp.js" type="text/javascript"></script>

In order to use the hierarchical processing feature, the XSLT ./xsl/xlp-get-steps.xsl must also be served, for example from the URL /static/xsl/xlp-get-steps.xsl. The URL prefix can be configured using the variable xlp.base.

XHLP usage

Create a XHLP pipeline using the function xlp.mkXLP, giving it a list of stylesheet URLs and a base URL from where to download the stylesheets.

var viewTransform = xlp.mkXLP(['xsl/filter1.xsl', 'xsl/filter2.xsl'], '/static/')
viewTransform.transform(document.documentElement.outerHTML, function(result) {
   document.documentElement.outerHTML = result.documentElement.outerHTML
})

Create a XHLP pipeline using the function xlp.mkXLP, giving it a list of stylesheet URLs and a base URL from where to download the stylesheets.

var viewTransform = xlp.mkXLP(['xml/xhlp-pipeline.xml'], '/static/')
viewTransform.transform(document.documentElement.outerHTML, function(result) {
   document.documentElement.outerHTML = result.documentElement.outerHTML
})

If you want to produce text output, set the second argument toDoc to false:

viewTransform.transform(document.documentElement.outerHTML, true, function(result) {
   document.querySelector('#textbox').value = result.textContent
})