xmlvalidate.js

Validates XML documents against a W3C XML Schema (XSD) from the comfort of your browser.

Dependency

Emscripten

Building

On POSIX

git submodule update --init --recursive
./emmake.sh

On other OSs

This is what emmake.sh does for you on POSIX:

1. copy xmlvalidate.c into the ./libxml2 directory

2. change working directory to ./libxml2

3. patch Makefile.am to include xmlvalidate.c in its libxml2_la_SOURCES

4. emconfigure ./autogen.sh --with-minimum --with-schemas --disable-shared

   If your system does not provide a Bourne shell, consider using autoreconf --install in place of ./autogen.sh and crossing your fingers.

5. emmake make

6. compile the new object file xmlvalidate.o to xmlvalidate.js:

   OBJECTS="SAX.o entities.o encoding.o error.o parserInternals.o  \
       parser.o tree.o hash.o list.o xmlIO.o xmlmemory.o uri.o  \
       valid.o xlink.o HTMLparser.o HTMLtree.o debugXML.o xpath.o  \
       xpointer.o xinclude.o nanohttp.o nanoftp.o \
       catalog.o globals.o threads.o c14n.o xmlstring.o buf.o \
       xmlregexp.o xmlschemas.o xmlschemastypes.o xmlunicode.o \
       xmlreader.o relaxng.o dict.o SAX2.o \
       xmlwriter.o legacy.o chvalid.o pattern.o xmlsave.o \
       xmlmodule.o schematron.o xzlib.o"
   
   emcc -Os xmlvalidate.o $OBJECTS -o xmlvalidate.js \
   -s ALLOW_MEMORY_GROWTH=1 \
   -s EXPORTED_FUNCTIONS='["_validate", "_init"]' \
   -s EXPORTED_RUNTIME_METHODS='["cwrap"]' \
   -s 'ENVIRONMENT=worker' \
   --pre-js ../pre.js --post-js ../post.js

7. move the resulting xmlvalidate.wasm and xlvalidate.js to ../dist/

8. change working directory to ..

Replicate these steps manually in order to compile xmlvalidate.js on a non-POSIX-compliant operating system.

Usage

Instantiate a WebWorker for validating against your schemas like so:

if (window.Worker) {
  const worker = new Worker('worker.js');
  worker.postMessage({ content: xsd_content, name: "filename.xsd" });
  // a filename ending in ".xsd" tells the worker to load the schema
  worker.onmessage = e => {
    if (e.data.file === "filename.xsd" && e.data.loaded) {
      // our schema has been parsed and loaded
      worker.postMessage({ content: xml_content, name: "filename.xml" });
      // a filename not ending in ".xsd" tells the worker to validate
    } else if (e.data.file === "filename.xml") { // respond to errors
      console.log(e.data);
    }
  };
}

License

Apache 2.0

© 2020 OMICRON electronics GmbH