expat-wasm

An XML parser based on expat.

The approach taken here was to compile to WASM with
emscripten, and ship the WASM binary in the NPM
package. This means you get a real, battle-tested XML parser, with 0 runtime
dependencies.

To install:

npm install --save expat-wasm

To use:

``js
import {XmlParser} from 'expat-wasm'

parser = new XmlParser()
parser.on('startElement', (name, attributes) => ...)
parser.parse('')
parser.destroy()
`

You may enable expansion of external entity references, if you are very
careful about not allowing access to unwanted files.

`js
parser = new XmlParser({
systemEntity(base, sysId, pubId) {
// Check the new URL to ensure it is "safe", for your local definition of "safe".
return {
base: new URL(sysId, base).toString(),
data: Buffer.from(''),
}
},
})
`

The systemEntity function MUST be synchronous, due to limitations of expat.
If you need to read from the network asynchronously, one approach might be to
call parser.stop()`, wait until you've got all of the needed data, then try
parsing again.

There are docs.

Requires nodejs 16 or higher, and works in a modern browser using WebPack. See
the webpack-demo
directory for simple WebPack example.

Note that expat currently only supports XML 1.0, edition 4.

See an online demo here.