commenthol / xml-vs-js

Convert XML/ HTML to Javascript and vice versa

xml-vs-js

Convert XML/ HTML to Javascript and vice versa

Features:

• Uses htmlparser2 to convert from xml to js.
• Processes html as well as xml - default is xmlMode=true.
• Respects order of elements with _elems array.
• Intented for manipulating/ parsing feeds or xml files where a full DOM is not required.
• Usage of plain JSON object for easy storage.
• Handles different xml namespaces.

Why another xml to js converter?

xml-js uses sax for xml conversion which requires valid xml as input. For manipulation of xml files where input and output is xml, the compact format does not respect the correct order of elements. Non-compact mode on the other hand is cumbersome for access of nodes. I wanted to have same JSON format for in- and output.

For syntax of the Js Object please refer to the test fixtures in ./test/fixtures

Table of Contents

• Conversion from XML to Js
  • Example toJs
  • Promises API
• Conversion from Js to XML
  • Example toXml
  • Promises API
  • Example toXml with order of elems
• Simplify object
• License
• References

Conversion from XML to Js

toJs(xml, opts, (err, obj) => {})

• see https://github.com/fb55/htmlparser2/wiki/Parser-options
• {String} xml
• {Object} [opts] - htmlparser2 options
• {Object} [opts.xmlMode=true] - xmlMode is set by default; Set to false for html
• {Object} [opts.decodeEntities=false] - decode entities
• {Object} [opts.recognizeSelfClosing=true] - recognize self closing tags in html
• {Object} [opts.recognizeCDATA=true] - recognize CDATA tags in html
• {Boolean} [opts.elems] - set to false if output shall not contain _elems fields; order of xml elements is not guarateed any longer.
• {Boolean} [opts.attrs] - set to false if output shall not contain any attributes _attrs fields;
• {Boolean} [opts.ns] - set to false if output shall not contain any namespace _ns fields;
• {Function} cb - callback(err, obj)

Example toJs

const {toJs} = require('xml-vs-js')

const xml = `
<?xml version="1.0" encoding=utf-8 ?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <title>Example Feed</title>
  <entry>
    <title>Entry</title>
    <link href="http://example.org/2003/12/13/atom03" />
    <link rel="alternate" type="text/html" href="http://example.org/2003/12/13/atom03.html"/>
  </entry>
  <entry>
    <title>Update</title>
  </entry>
</feed>
`

toJs(xml, (err, obj) => {
  console.log(obj)
  /*
  {
    _elems: ['_PROCESSING', 'feed'],
    _PROCESSING: {
      _text: '?xml version="1.0" encoding=utf-8 ?'
    },
    feed: {
      _attrs: {
        xmlns: 'http://www.w3.org/2005/Atom'
      },
      _elems: ['title', 'entry', 'entry'],
      title: {
        _elems: ['_text'],
        _text: 'Example Feed'
      },
      entry: [{
        _elems: ['title', 'link', 'link'],
        title: {
          _elems: ['_text'],
          _text: 'Entry'
        },
        link: [{
          _attrs: {
            href: 'http://example.org/2003/12/13/atom03'
          }
        }, {
          _attrs: {
            rel: 'alternate',
            type: 'text/html',
            href: 'http://example.org/2003/12/13/atom03.html'
          }
        }]
      }, {
        _elems: ['title'],
        title: {
          _elems: ['_text'],
          _text: 'Update'
        }
      }]
    }
  }
*/    
})

Promises API

const {toJs} = require('xml-vs-js/promises')

const obj = await toJs(xml, opts)

Conversion from Js to XML

toXml(obj, opts, (err, xml) => {})

• {Object} obj - the object to convert to xml
• {Object} [opts] - options
• {Boolean} [opts.xmlMode=true] - xmlMode is set by default; Set to false for html
• {Boolean} [opts.encodeEntities=false] - encode entities

Example toXml

Note: _elems are optional. In case the field is missing the order of elements returned with Object.keys() is used.

const {toXml} = require('xml-vs-js')

const obj = {
  root: {
    _COMMENT: ' example wo order of elements ',
    section: {
      _attrs: { class: 'blue' },
      span: ['one', 'four'],
      _text: 'three',
      strong: 'two'
    }
  }
}
toXml(obj, (err, xml) => {
  console.log(xml)
  // <root>
  //  <!-- example wo order of elements -->
  //  <section class="blue">
  //  <span>one</span><span>four</span>three<strong>two</strong>
  //  </section>
  // </root>
})

Promises API

const {toXml} = require('xml-vs-js/promises')

const xml = await toXml(obj, opts)

Example toXml with order of elems

const {toXml} = require('xml-vs-js')

const obj = {
  _PROCESSING: {
    _text: '?xml version="1.0" encoding="utf-8"?'
  },
  root: {
    section: {
      _elems: ['span', 'strong', '_text', 'span'],
      span: ['one', 'four'],
      _text: 'three',
      strong: 'two'
    }
  }
}
toXml(obj, (err, xml) => {
  console.log(xml)
  // <?xml version="1.0" encoding="utf-8"?>
  // <root>
  //  <section>
  //  <span>one</span><strong>two</strong>three<span>four</span>
  //  </section>
  // </root>
})

Simplify object

toObj(obj, opts)

• {Object} obj - the object to simplify
• {Object} [opts] - options
• {Boolean} [opts.elems] - if false remove all _elems props
• {Boolean} [opts.attrs] - if false remove all _attrs props
• {Boolean} [opts.ns] - if false remove all _ns props

To further simplify the object structure from toJS use the toObj method:

const {toJs, toObj} = require('../promises.js')

const xml = `
<feed xmlns="http://www.w3.org/2005/Atom">
  <title>Example Feed</title>
  <entry>
    <title>Entry</title>
    <link href="http://example.org/2003/12/13/atom03" />
    <link rel="alternate" type="text/html" href="http://example.org/2003/12/13/atom03.html"/>
  </entry>
  <entry>
    <title>Update</title>
  </entry>
</feed>
`

const obj = await toJs(xml)
const simple = toObj(obj, {elems: false, attrs: true})
console.log(simple)
/*
{
  feed: {
    _attrs: { xmlns: 'http://www.w3.org/2005/Atom' },
    title: 'Example Feed',
    entry: [
      {
        title: 'Entry',
        link: [
          { _attrs: { href: 'http://example.org/2003/12/13/atom03' } },
          {
            _attrs: {
              rel: 'alternate',
              type: 'text/html',
              href: 'http://example.org/2003/12/13/atom03.html'
            }
          }
        ]
      },
      { title: 'Update' }
    ]
  }
}
*/

License

Unlicense https://unlicense.org

References

• htmlparser2
• xml-js