XJSLT - An XSLT compiler in TypeScript

XJSLT is an XSLT 2.0 compiler (targeting JavaScript) written in TypeScript, depending on fontoxpath for an XPath implementation.

XJSLT works by compiling stylesheets to runnable JavaScript. These compiled stylesheets can be used immediately in the command line, or they can be save for later use in the command line. They can also be used programmatically either in the browser or in another JavaScript runtime.

Tested with node 20 and in Chrome and Firefox.

Getting started

Installation:

npm install && npm run build

Command line invocation:

xjslt jats-html.xsl <(curl -s https://jats.nlm.nih.gov/publishing/tag-library/1.1/FullArticleSamples/bmj_sample.xml)

Compilation examples

XJSLT can compile XSLT stylesheets into executable JavaScript code, which can then be deployed to various platforms that support JavaScript, including the browser, NodeJS, and potentially other JavaScript runtimes. The following are some examples of how to do this for the browser, google cloud functions, and cloudflare edge functions. Note that this compiled .js may need to be recompiled if the xjslt version changes.

In the browser

xjslt compile --web jats-html.xsl examples/html/transform.js
Open examples/html/example.html (will load the generated transform.js file)

For reuse in the command line

xjslt compile jats-html.xsl
xjslt transform.js <(curl -s https://jats.nlm.nih.gov/publishing/tag-library/1.1/FullArticleSamples/bmj_sample.xml)

In a google cloud function

xjslt compile --standalone jats-html.xsl examples/google-cloud/transform.js
cd examples/google-cloud
npm install
npx @google-cloud/functions-framework --target=transform
Visit http://localhost:8080/?url=https://jats.nlm.nih.gov/publishing/tag-library/1.1/FullArticleSamples/bmj_sample.xml

In a cloudflare edge function

xjslt compile --standalone jats-html.xsl examples/cloudflare/src/transform.js
cd examples/cloudflare
npm install
npm run start
Visit http://localhost:8787/?url=https://jats.nlm.nih.gov/publishing/tag-library/1.1/FullArticleSamples/bmj_sample.xml

Supported features

if/choose/when/otherwise - conditional evaluation
template
apply-templates/for-each - recursive evaluation
element/attribute/value-of - dynamic elements, attributes, and text
literal text and xml element output
variable
namespaces
sort
include/import
result-document
2108 passing tests in the XSLT test suite (https://github.com/w3c/xslt30-test) (2528 not passing)

Incompletely supported features

for-each-group (only group-by supported)
function basically working, with better typing TBD
output not all options supported

TODO (not yet implemented)

attribute-set
number
tunneled parameters
… (probably other things I’m not aware of or forgot)