jsonml.js/lib/dom.js

JsonML-related tools for losslessly converting between XML/HTML and JSON, including mixed-mode XML. http://jsonml.org

/*
 jsonml-dom.js
 HTML to JsonML utility

 Created: 2007-02-15-2235

 Copyright (c)2006-2012 Stephen M. McKamey
 Distributed under The MIT License: http://jsonml.org/license
*/


'use strict';

const jsdom = require('jsdom').jsdom;

var addChildren = function(/*DOM*/ elem, /*function*/ filter, /*JsonML*/ jml) {
  if (elem.hasChildNodes()) {
    for (var i=0; i<elem.childNodes.length; i++) {
      var child = elem.childNodes[i];
      child = fromHTML(child, filter);
      if (child) {
	jml.push(child);
      }
    }
    return true;
  }
  return false;
};

/**
 * @param {Node} elem
 * @param {function} filter
 * @return {array} JsonML
 */
var fromHTML = exports.fromHTML = function(elem, filter) {
  if (!elem || !elem.nodeType) {
    // free references
    return (elem = null);
  }

  var i, jml;
  switch (elem.nodeType) {
  case 1:  // element
  case 9:  // document
  case 11: // documentFragment
    jml = [elem.tagName.toLowerCase()||''];

    var attr = elem.attributes,
	props = {},
	hasAttrib = false;

    for (i=0; attr && i<attr.length; i++) {
      if (attr[i].specified) {
	if (attr[i].name === 'style') {
	  props.style = elem.style.cssText || attr[i].value;
	} else if ('string' === typeof attr[i].value) {
	  props[attr[i].name] = attr[i].value;
	}
	hasAttrib = true;
      }
    }
    if (hasAttrib) {
      jml.push(props);
    }

    var child;
    switch (jml[0].toLowerCase()) {
    case 'frame':
    case 'iframe':
      try {
	if ('undefined' !== typeof elem.contentDocument) {
	  // W3C
	  child = elem.contentDocument;
	} else if ('undefined' !== typeof elem.contentWindow) {
	  // Microsoft
	  child = elem.contentWindow.document;
	} else if ('undefined' !== typeof elem.document) {
	  // deprecated
	  child = elem.document;
	}
	
	child = fromHTML(child, filter);
	if (child) {
	  jml.push(child);
	}
      } catch (ex) {}
      break;
    case 'style':
      child = elem.styleSheet && elem.styleSheet.cssText;
      if (child && 'string' === typeof child) {
	// unwrap comment blocks
	child = child.replace('<!--', '').replace('-->', '');
	jml.push(child);
      } else if (elem.hasChildNodes()) {
	for (i=0; i<elem.childNodes.length; i++) {
	  child = elem.childNodes[i];
	  child = fromHTML(child, filter);
	  if (child && 'string' === typeof child) {
	    // unwrap comment blocks
	    child = child.replace('<!--', '').replace('-->', '');
	    jml.push(child);
	  }
	}
      }
      break;
    case 'input':
      addChildren(elem, filter, jml);
      child = (elem.type !== 'password') && elem.value;
      if (child) {
	if (!hasAttrib) {
	  // need to add an attribute object
	  jml.shift();
	  props = {};
	  jml.unshift(props);
	  jml.unshift(elem.tagName.toLowerCase()||'');
	}
	props.value = child;
      }
      break;
    case 'textarea':
      if (!addChildren(elem, filter, jml)) {
	child = elem.value || elem.innerHTML;
	if (child && 'string' === typeof child) {
	  jml.push(child);
	}
      }
      break;
    default:
      addChildren(elem, filter, jml);
      break;
    }

    // filter result
    if ('function' === typeof filter) {
      jml = filter(jml, elem);
    }

    // free references
    elem = null;
    return jml;
  case 3: // text node
  case 4: // CDATA node
    var str = String(elem.nodeValue);
    // free references
    elem = null;
    return /^(\n|\s)+$/.test(str) ? null : str;
  case 10: // doctype
    jml = ['!'];

    var type = ['DOCTYPE', (elem.name || 'html').toLowerCase()];

    if (elem.publicId) {
      type.push('PUBLIC', '"' + elem.publicId + '"');
    }

    if (elem.systemId) {
      type.push('"' + elem.systemId + '"');
    }

    jml.push(type.join(' '));

    // filter result
    if ('function' === typeof filter) {
      jml = filter(jml, elem);
    }

    // free references
    elem = null;
    return jml;
  case 8: // comment node
    if ((elem.nodeValue||'').indexOf('DOCTYPE') !== 0) {
      // free references
      elem = null;
      return null;
    }

    jml = ['!',
	   elem.nodeValue];

    // filter result
    if ('function' === typeof filter) {
      jml = filter(jml, elem);
    }

    // free references
    elem = null;
    return jml;
  default: // etc.
    // free references
    return (elem = null);
  }
};

const doc = typeof document === 'undefined' ?
      jsdom(undefined, {}) :
      document;

/**
 * @param {string} html HTML text
 * @param {function} filter
 * @return {array} JsonML
 */
exports.fromHTMLText = function(html, filter) {
  var elem = doc.createElement('div');
  elem.innerHTML = html;

  var jml = fromHTML(elem, filter);

  // free references
  elem = null;

  if (jml.length === 2) {
    return jml[1];
  }

  // make wrapper a document fragment
  jml[0] = '';
  return jml;
};