domador.js

'use strict';

require('string.prototype.repeat');

var replacements = {
  '\\\\': '\\\\',
  '\\[': '\\[',
  '\\]': '\\]',
  '>': '\\>',
  '_': '\\_',
  '\\*': '\\*',
  '`': '\\`',
  '#': '\\#',
  '([0-9])\\.(\\s|$)': '$1\\.$2',
  '\u00a9': '(c)',
  '\u00ae': '(r)',
  '\u2122': '(tm)',
  '\u00a0': ' ',
  '\u00b7': '\\*',
  '\u2002': ' ',
  '\u2003': ' ',
  '\u2009': ' ',
  '\u2018': '\'',
  '\u2019': '\'',
  '\u201c': '"',
  '\u201d': '"',
  '\u2026': '...',
  '\u2013': '--',
  '\u2014': '---'
};
var replacers = Object.keys(replacements).reduce(replacer, {});
var rspaces = /^\s+|\s+$/g;
var rdisplay = /(display|visibility)\s*:\s*[a-z]+/gi;
var rhidden = /(none|hidden)\s*$/i;
var rheading = /^H([1-6])$/;
var shallowTags = [
  'APPLET', 'AREA', 'AUDIO', 'BUTTON', 'CANVAS', 'DATALIST', 'EMBED', 'HEAD', 'INPUT', 'MAP',
  'MENU', 'METER', 'NOFRAMES', 'NOSCRIPT', 'OBJECT', 'OPTGROUP', 'OPTION', 'PARAM', 'PROGRESS',
  'RP', 'RT', 'RUBY', 'SCRIPT', 'SELECT', 'STYLE', 'TEXTAREA', 'TITLE', 'VIDEO'
];
var paragraphTags = [
  'ADDRESS', 'ARTICLE', 'ASIDE', 'DIV', 'FIELDSET', 'FOOTER', 'HEADER', 'NAV', 'P', 'SECTION'
];
var blockTags = [
  'ADDRESS', 'ARTICLE', 'ASIDE', 'DIV', 'FIELDSET', 'FOOTER', 'HEADER', 'NAV', 'P', 'SECTION', 'UL', 'LI', 'BLOCKQUOTE', 'BR'
];
var windowContext = require('./virtualWindowContext');

function replacer (result, key) {
  result[key] = new RegExp(key, 'g'); return result;
}

function many (text, times) {
  return new Array(times + 1).join(text);
}

function padLeft (text, times) {
  return many(' ', times) + text;
}

function trim (text) {
  if (text.trim) {
    return text.trim();
  }
  return text.replace(rspaces, '');
}

function attr (el, prop, direct) {
  var proper = direct === void 0 || direct;
  if (proper || typeof el.getAttribute !== 'function') {
    return el[prop] || '';
  }
  return el.getAttribute(prop) || '';
}

function has (el, prop, direct) {
  var proper = direct === void 0 || direct;
  if (proper || typeof el.hasAttribute !== 'function') {
    return el.hasOwnProperty(prop);
  }
  return el.hasAttribute(prop);
}

function processPlainText (text, tagName) {
  var key;
  var block = paragraphTags.indexOf(tagName) !== -1 || tagName === 'BLOCKQUOTE';
  text = text.replace(/\n([ \t]*\n)+/g, '\n');
  text = text.replace(/\n[ \t]+/g, '\n');
  text = text.replace(/[ \t]+/g, ' ');
  for (key in replacements) {
    text = text.replace(replacers[key], replacements[key]);
  }
  text = text.replace(/(\s*)\\#/g, block ? removeUnnecessaryEscapes : '$1#');
  return text;

  function removeUnnecessaryEscapes (escaped, spaces, i) {
    return i ? spaces + '#' : escaped;
  }
}

function processCode (text) {
  return text.replace(/`/g, '\\`');
}

function outputMapper (fn, tagName) {
  return function bitProcessor (bit) {
    if (bit.marker) {
      return bit.marker;
    }
    if (!fn) {
      return bit.text;
    }
    return fn(bit.text, tagName);
  };
}

function noop () {}

function parse (html, options) {
  return new Domador(html, options).parse();
}

function Domador (html, options) {
  this.html = html || '';
  this.htmlIndex = 0;
  this.options = options || {};
  this.markers = this.options.markers ? this.options.markers.sort(asc) : [];
  this.windowContext = windowContext(this.options);
  this.atLeft = this.noTrailingWhitespace = this.atP = true;
  this.buffer = this.childBuffer = '';
  this.exceptions = [];
  this.order = 1;
  this.listDepth = 0;
  this.inCode = this.inPre = this.inOrderedList = this.inTable = false;
  this.last = null;
  this.left = '\n';
  this.links = [];
  this.linkMap = {};
  this.unhandled = {};
  if (this.options.absolute === void 0) { this.options.absolute = false; }
  if (this.options.fencing === void 0) { this.options.fencing = false; }
  if (this.options.fencinglanguage === void 0) { this.options.fencinglanguage = noop; }
  if (this.options.transform === void 0) { this.options.transform = noop; }
  function asc (a, b) { return a[0] - b[0]; }
}

Domador.prototype.append = function append (text) {
  if (this.last != null) {
    this.buffer += this.last;
  }
  this.childBuffer += text;
  return this.last = text;
};

Domador.prototype.br = function br () {
  this.append('  ' +  this.left);
  return this.atLeft = this.noTrailingWhitespace = true;
};

Domador.prototype.code = function code () {
  var old;
  old = this.inCode;
  this.inCode = true;
  return (function(_this) {
    return function after () {
      return _this.inCode = old;
    };
  })(this);
};

Domador.prototype.li = function li () {
  var result;
  result = this.inOrderedList ? (this.order++) + '. ' : '- ';
  result = padLeft(result, (this.listDepth - 1) * 2);
  return this.append(result);
};

Domador.prototype.td = function td (header) {
  this.noTrailingWhitespace = false;
  this.output(' ');
  this.childBuffer = '';
  this.noTrailingWhitespace = false;
  return function after () {
    var spaces = header ? 0 : Math.max(0, this.tableCols[this.tableCol++] - this.childBuffer.length);
    this.append(' '.repeat(spaces + 1) + '|');
    this.noTrailingWhitespace = true;
  };
};

Domador.prototype.ol = function ol () {
  var inOrderedList, order;
  if (this.listDepth === 0) {
    this.p();
  }
  inOrderedList = this.inOrderedList;
  order = this.order;
  this.inOrderedList = true;
  this.order = 1;
  this.listDepth++;
  return (function(_this) {
    return function after () {
      _this.inOrderedList = inOrderedList;
      _this.order = order;
      return _this.listDepth--;
    };
  })(this);
};

Domador.prototype.ul = function ul () {
  var inOrderedList, order;
  if (this.listDepth === 0) {
    this.p();
  }
  inOrderedList = this.inOrderedList;
  order = this.order;
  this.inOrderedList = false;
  this.order = 1;
  this.listDepth++;
  return (function(_this) {
    return function after () {
      _this.inOrderedList = inOrderedList;
      _this.order = order;
      return _this.listDepth--;
    };
  })(this);
};

Domador.prototype.output = function output (text) {
  if (!text) {
    return;
  }
  if (!this.inPre) {
    text = this.noTrailingWhitespace ? text.replace(/^[ \t\n]+/, '') : /^[ \t]*\n/.test(text) ? text.replace(/^[ \t\n]+/, '\n') : text.replace(/^[ \t]+/, ' ');
  }
  if (text === '') {
    return;
  }
  this.atP = /\n\n$/.test(text);
  this.atLeft = /\n$/.test(text);
  this.noTrailingWhitespace = /[ \t\n]$/.test(text);
  return this.append(text.replace(/\n/g, this.left));
};

Domador.prototype.outputLater = function outputLater (text) {
  return (function(self) {
    return function after () {
      return self.output(text);
    };
  })(this);
};

Domador.prototype.p = function p () {
  if (this.atP) {
    return;
  }
  if (this.startingBlockquote) {
    this.append('\n');
  } else {
    this.append(this.left);
  }
  if (!this.atLeft) {
    this.append(this.left);
    this.atLeft = true;
  }
  return this.noTrailingWhitespace = this.atP = true;
};

Domador.prototype.parse = function parse () {
  var container;
  var i;
  var link;
  var ref;
  this.buffer = '';
  if (!this.html) {
    return this.buffer;
  }
  if (typeof this.html === 'string') {
    container = this.windowContext.document.createElement('div');
    container.innerHTML = this.htmlLeft = this.html;
  } else {
    container = this.html;
    this.html = this.htmlLeft = container.innerHTML;
  }
  this.process(container);
  if (this.links.length) {
    while (this.lastElement.parentElement !== container && this.lastElement.tagName !== 'BLOCKQUOTE') {
      this.lastElement = this.lastElement.parentElement;
    }
    if (this.lastElement.tagName !== 'BLOCKQUOTE') {
      this.append('\n\n');
    }
    ref = this.links;
    for (i = 0; i < ref.length; i++) {
      link = ref[i];
      if (link) {
        this.append('[' + (i + 1) + ']: ' + link + '\n');
      }
    }
  }
  this.append('');
  this.buffer = this.buffer.replace(/\n{3,}/g, '\n\n');
  return this.buffer = trim(this.buffer);
};

Domador.prototype.pre = function pre () {
  var old;
  old = this.inPre;
  this.inPre = true;
  return (function(_this) {
    return function after () {
      return _this.inPre = old;
    };
  })(this);
};

Domador.prototype.htmlTag = function htmlTag (type) {
  this.output('<' + type + '>');
  return this.outputLater('</' + type + '>');
};

Domador.prototype.advanceHtmlIndex = function advanceHtmlIndex (token) {
  if (this.markers.length === 0) {
    return;
  }

  var re = new RegExp(token, 'ig');
  var match = re.exec(this.htmlLeft);
  if (!match) {
    return;
  }
  var diff = re.lastIndex;
  this.htmlIndex += diff;
  this.htmlLeft = this.htmlLeft.slice(diff);
};

Domador.prototype.insertMarkers = function insertMarkers () {
  while (this.markers.length && this.markers[0][0] <= this.htmlIndex) {
    this.append(this.markers.shift()[1]);
  }
};

Domador.prototype.interleaveMarkers = function interleaveMarkers (text) {
  var marker;
  var markerStart;
  var lastMarkerStart = 0;
  var bits = [];
  while (this.markers.length && this.markers[0][0] <= this.htmlIndex + text.length) {
    marker = this.markers.shift();
    markerStart = Math.max(0, marker[0] - this.htmlIndex);
    bits.push(
      { text: text.slice(lastMarkerStart, markerStart) },
      { marker: marker[1] }
    );
    lastMarkerStart = markerStart;
  }
  bits.push({ text: text.slice(lastMarkerStart) });
  return bits;
};

Domador.prototype.process = function process (el) {
  var after;
  var base;
  var href;
  var i;
  var ref;
  var suffix;
  var summary;
  var title;
  var frameSrc;
  var interleaved;

  if (!this.isVisible(el)) {
    return;
  }

  if ((this.inTable || this.inPre) && blockTags.indexOf(el.tagName) !== -1) {
    return this.output(el.outerHTML);
  }

  if (el.nodeType === this.windowContext.Node.TEXT_NODE) {
    if (!this.inPre && el.nodeValue.replace(/\n/g, '').length === 0) {
      return;
    }
    interleaved = this.interleaveMarkers(el.nodeValue);
    if (this.inPre || this.inTable) {
      return this.output(interleaved.map(outputMapper()).join(''));
    }
    if (this.inCode) {
      return this.output(interleaved.map(outputMapper(processCode)).join(''));
    }
    return this.output(interleaved.map(outputMapper(processPlainText, el.parentElement && el.parentElement.tagName)).join(''));
  }

  if (el.nodeType !== this.windowContext.Node.ELEMENT_NODE) {
    return;
  }

  if (this.lastElement) { // i.e not the auto-inserted <div> wrapper
    this.insertMarkers();
    this.advanceHtmlIndex('<' + el.tagName);
    this.advanceHtmlIndex('>');

    var transformed = this.options.transform(el);
    if (transformed !== void 0) {
      return this.output(transformed);
    }
  }
  this.lastElement = el;

  if (shallowTags.indexOf(el.tagName) !== -1) {
    this.advanceHtmlIndex('\\/\\s?>');
    return;
  }

  switch (el.tagName) {
    case 'H1':
    case 'H2':
    case 'H3':
    case 'H4':
    case 'H5':
    case 'H6':
      this.p();
      this.output(many('#', parseInt(el.tagName.match(rheading)[1])) + ' ');
      break;
    case 'ADDRESS':
    case 'ARTICLE':
    case 'ASIDE':
    case 'DIV':
    case 'FIELDSET':
    case 'FOOTER':
    case 'HEADER':
    case 'NAV':
    case 'P':
    case 'SECTION':
      this.p();
      break;
    case 'BODY':
    case 'FORM':
      break;
    case 'DETAILS':
      this.p();
      if (!has(el, 'open', false)) {
        summary = el.getElementsByTagName('summary')[0];
        if (summary) {
          this.process(summary);
        }
        return;
      }
      break;
    case 'BR':
      this.br();
      break;
    case 'HR':
      this.p();
      this.output('---------');
      this.p();
      break;
    case 'CITE':
    case 'DFN':
    case 'EM':
    case 'I':
    case 'U':
    case 'VAR':
      this.output('_');
      this.noTrailingWhitespace = true;
      after = this.outputLater('_');
      break;
    case 'MARK':
      this.output('<mark>');
      after = this.outputLater('</mark>');
      break;
    case 'DT':
    case 'B':
    case 'STRONG':
      if (el.tagName === 'DT') {
        this.p();
      }
      this.output('**');
      this.noTrailingWhitespace = true;
      after = this.outputLater('**');
      break;
    case 'Q':
      this.output('"');
      this.noTrailingWhitespace = true;
      after = this.outputLater('"');
      break;
    case 'OL':
      after = this.ol();
      break;
    case 'UL':
      after = this.ul();
      break;
    case 'LI':
      this.replaceLeft('\n');
      this.li();
      break;
    case 'PRE':
      if (this.options.fencing) {
        this.append('\n\n');
        this.openCodeFence(el);
        after = [this.pre(), this.outputLater('\n```')];
      } else {
        after = [this.pushLeft('    '), this.pre()];
      }
      break;
    case 'CODE':
    case 'SAMP':
      if (this.inPre) {
        break;
      }
      this.output('`');
      after = [this.code(), this.outputLater('`')];
      break;
    case 'BLOCKQUOTE':
    case 'DD':
      this.startingBlockquote = true;
      after = this.pushLeft('> ');
      this.startingBlockquote = false;
      break;
    case 'KBD':
      after = this.htmlTag('kbd');
      break;
    case 'A':
    case 'IMG':
      href = attr(el, el.tagName === 'A' ? 'href' : 'src', this.options.absolute);
      if (!href) {
        break;
      }
      title = attr(el, 'title');
      if (title) {
        href += ' "' + title + '"';
      }
      if (this.options.inline) {
        suffix = '(' + href + ')';
      } else {
        suffix = '[' + ((base = this.linkMap)[href] != null ? base[href] : base[href] = this.links.push(href)) + ']';
      }
      if (el.tagName === 'IMG') {
        this.output('![' + attr(el, 'alt') + ']' + suffix);
        return;
      }
      this.output('[');
      this.noTrailingWhitespace = true;
      after = this.outputLater(']' + suffix);
      break;
    case 'IFRAME':
      try {
        if ((ref = el.contentDocument) != null ? ref.documentElement : void 0) {
          this.process(el.contentDocument.documentElement);
        } else {
          frameSrc = attr(el, 'src');
          if (frameSrc && this.options.allowFrame && this.options.allowFrame(frameSrc)) {
            this.output('<iframe src="' + frameSrc + '"></iframe>');
          }
        }
      } catch (err) {
      }
      return;
  }

  after = this.tables(el) || after;

  for (i = 0; i < el.childNodes.length; i++) {
    this.process(el.childNodes[i]);
  }

  this.advanceHtmlIndex('<\\s?\\/\\s?' + el.tagName + '>');

  if (typeof after === 'function') {
    after = [after];
  }
  while (after && after.length) {
    after.shift().call(this);
  }
};

Domador.prototype.tables = function tables (el) {
  if (this.options.tables === false) {
    return;
  }

  var name = el.tagName;
  if (name === 'TABLE') {
    var oldInTable;
    oldInTable = this.inTable;
    this.inTable = true;
    this.append('\n\n');
    this.tableCols = [];
    return (function(_this) {
      return function after () {
        return _this.inTable = oldInTable;
      };
    })(this);
  }
  if (name === 'THEAD') {
    return function after () {
      return this.append('|' + this.tableCols.reduce(reducer, '') + '\n');
      function reducer (all, thLength) {
        return all + '-'.repeat(thLength + 2) + '|';
      }
    };
  }
  if (name === 'TH') {
    return [function after () {
      this.tableCols.push(this.childBuffer.length);
    }, this.td(true)];
  }
  if (name === 'TR') {
    this.tableCol = 0;
    this.output('|');
    this.noTrailingWhitespace = true;
    return function after () {
      this.append('\n');
    };
  }
  if (name === 'TD') {
    return this.td();
  }
};

Domador.prototype.pushLeft = function pushLeft (text) {
  var old;
  old = this.left;
  this.left += text;
  if (this.atP) {
    this.append(text);
  } else {
    this.p();
  }
  return (function(_this) {
    return function() {
      _this.left = old;
      _this.atLeft = _this.atP = false;
      return _this.p();
    };
  })(this);
};

Domador.prototype.replaceLeft = function replaceLeft (text) {
  if (!this.atLeft) {
    this.append(this.left.replace(/[ ]{2,4}$/, text));
    return this.atLeft = this.noTrailingWhitespace = this.atP = true;
  } else if (this.last) {
    return this.last = this.last.replace(/[ ]{2,4}$/, text);
  }
};

Domador.prototype.isVisible = function isVisible (el) {
  var display;
  var i;
  var property;
  var visibility;
  var visible = true;
  var style = attr(el, 'style', false);
  var properties = style != null ? typeof style.match === 'function' ? style.match(rdisplay) : void 0 : void 0;
  if (properties != null) {
    for (i = 0; i < properties.length; i++) {
      property = properties[i];
      visible = !rhidden.test(property);
    }
  }
  if (visible && typeof this.windowContext.getComputedStyle === 'function') {
    try {
      style = this.windowContext.getComputedStyle(el, null);
      if (typeof (style != null ? style.getPropertyValue : void 0) === 'function') {
        display = style.getPropertyValue('display');
        visibility = style.getPropertyValue('visibility');
        visible = display !== 'none' && visibility !== 'hidden';
      }
    } catch (err) {
    }
  }
  return visible;
};

Domador.prototype.openCodeFence = function openCodeFence (el) {
  var fencinglanguage = this.options.fencinglanguage(el);
  var child = el.childNodes[0];
  if (!fencinglanguage && child && child.tagName === 'CODE') {
    fencinglanguage = this.options.fencinglanguage(el.childNodes[0]);
  }
  this.output('```' + (fencinglanguage || '') + '\n');
};

module.exports = parse;