pethessa / xml_to_json

xml_to_json(xml, indent) function

xml_to_json

Implementation of xml_to_json(xml, indent) function.

xml_to_json(xml, indent) takes two arguments:

• xml - XML string UTF-8 encoded
• indent - Indent for pretty printed JSON or -1 for minified JSON

The input XML is not validated prior to conversion.

TOC

• WebAssembly
  • Compile
  • Usage example:
• SQLite3
  • Compile
  • Usage examples
• Implementation Method
• TODO

WebAssembly

Demo

jakethaw.com/xml_to_json

Compile

To compile with Emscripten as a WebAssembly function:

emcc -Oz xml_to_json.c -o xml_to_json.js -s EXPORTED_FUNCTIONS='["_xml_to_json", "_free"]' -s 'EXTRA_EXPORTED_RUNTIME_METHODS=["allocate", "intArrayFromString", "ALLOC_NORMAL", "UTF8ToString"]'

Usage example:

var xml = allocate(intArrayFromString("<x>hello world</x>"), 'i8', ALLOC_NORMAL);
var indent = 2;

var json = _xml_to_json(xml, indent);
console.log(UTF8ToString(json, 5000));

_free(xml);
_free(json);

{
  "x": "hello world"
}

SQLite3

Implementation of an SQLite3 xml_to_json(X, N) function.

xml_to_json(X, N) takes one or two arguments:

• X - XML string UTF-8 encoded
• N - Optional indent for pretty printed JSON or -1 for minified JSON

The input XML is not validated prior to conversion.

Compile

To compile with gcc as a run-time loadable extension:

UNIX-like : gcc -g -O3 -fPIC -shared xml_to_json.c -o xml_to_json.so -DSQLITE
Mac       : gcc -g -O3 -fPIC -dynamiclib xml_to_json.c -o xml_to_json.dylib -DSQLITE
Windows   : gcc -g -O3 -shared xml_to_json.c -o xml_to_json.dll -DSQLITE

Add the -DDEBUG option to print debug information to stdout.

E.g.

gcc -g -O3 -fPIC -shared xml_to_json.c -o xml_to_json.so -DDEBUG

Usage examples

SELECT xml_to_json('<x>hello world</x>', 2);

{
  "x": "hello world"
}

---

SELECT xml_to_json('<x>a<y/>b</x>', 2);

{
  "x": {
    "#text": [
      "a",
      "b"
    ],
    "y": null
  }
}

---

SELECT xml_to_json('<x><y>abc</y><y>def</y></x>', 2);

{
  "x": {
    "y": [
      "abc",
      "def"
    ]
  }
}

---

SELECT xml_to_json('<x>hello<y>abc</y>world<y>def</y>xyz</x>', 2);

{
  "x": {
    "#text": [
      "hello",
      "world",
      "xyz"
    ],
    "y": [
      "abc",
      "def"
    ]
  }
}

---

SELECT xml_to_json('<x attr1="attr val 1" attr2="attr val 2">&amp; &gt; &lt; &#39;</x>', 2);

{
  "x": {
    "@attr1": "attr val 1",
    "@attr2": "attr val 2",
    "#text": "& > < '"
  }
}

Implementation Method

This implementation does not support the full XML 1.0 Specification. The following explaination is designed to describe what is currently supported.

TODO

TODO

• Improve readme
• Add test cases
• Benchmark