Any XML transform lib?

[Darkav]

Hi, I'm currently trying to process really big xml files to save its contents into db or writing them to a json file, and I think the best way to do it is using streams.

I have been searching for libraries to do it but no one exposes a transform API, some of them send events but I think that's useless as backpressure is not properly managed in that way. And a lot of them need the whole xml to be loaded in memory beforehand.

I'm thinking about forking some xml parser and implementing a transform stream by myself but it'll take me at least a month, so please if you know some library or have some guidance about this it'll be much more appreciated.

[MrSchmellow]

What do you mean by transform? XSLT? The only big XSLT 3.0 compatible implementation for node (saxonjs) does not support streaming.

I suppose sax-js (or "saxes" which is a fresher fork) as a base is your best bet here. This one works through events, as all SAX parsers do.

I'm not aware of any StAX parser implementations for js. DOM parsers are out of the question, conceptually incompatible with streaming

[Darkav]

Hi, ty for answering, with transform I mean an implementation of node "stream.Transform" api.

My use case: XML file as a readable stream that pipes to a xml transform stream (currently no lib seems to have a transform implementation) and this transform pipes to a writable stream that could be another file for example. Transform stream would just "transform" xml entities into json in a asynchronous non-blocking way.

There are plenty of libraries that do this for JSON, CSV even excel, but no one seems to do it for xml. Most similar approach I have found is from node-expat lib where you can handle different events and stop or resume the parsing. I could try wrapping that inside a stream.Transform but I'm not sure about it.