dox-draft-js-import-markdown/lib/MarkdownParser.js

DraftJS: Import Markdown to ContentState

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _syntheticDom2 = require('synthetic-dom');

var hasOwnProperty = Object.prototype.hasOwnProperty; /**
                                                       * Ported from:
                                                       *   https://github.com/chjj/marked/blob/49b7eaca/lib/marked.js
                                                       * TODO:
                                                       *   Use ES6 classes
                                                       *   Add flow annotations
                                                       */
/* eslint-disable no-spaced-func */

var assign = Object.assign || function (obj) {
  var i = 1;
  for (; i < arguments.length; i++) {
    var target = arguments[i];
    for (var key in target) {
      if (hasOwnProperty.call(target, key)) {
        obj[key] = target[key];
      }
    }
  }
  return obj;
};

var noop = function noop() {};
noop.exec = noop;

var defaults = {
  gfm: true,
  headings: true,
  underlines: true,
  breaks: false,
  pedantic: false,
  smartLists: false,
  silent: false,
  langPrefix: 'lang-',
  renderer: new Renderer(),
  xhtml: false
};

/**
 * Block-Level Grammar
 */

var block = {
  newline: /^\n+/,
  code: /^( {4}[^\n]+\n*)+/,
  fences: noop,
  hr: /^( *[-*_]){3,} *(?:\n+|$)/,
  heading: /^ *(#{1,6}) *([^\n]+?) *#* *(?:\n+|$)/,
  nptable: noop,
  lheading: /^([^\n]+)\n *(=|-){2,} *(?:\n+|$)/,
  blockquote: /^( *>[^\n]+(\n(?!def)[^\n]+)*\n*)+/,
  list: /^( *)(bull) [\s\S]+?(?:hr|def|\n{2,}(?! )(?!\1bull )\n*|\s*$)/,
  def: /^ *\[([^\]]+)\]: *<?([^\s>]+)>?(?: +["(]([^\n]+)[")])? *(?:\n+|$)/,
  paragraph: /^((?:[^\n]+\n?(?!hr|heading|lheading|blockquote|def))+)\n*/,
  text: /^[^\n]+/
};

block.bullet = /(?:[*+-]|\d+\.)/;
block.item = /^( *)(bull) [^\n]*(?:\n(?!\1bull )[^\n]*)*/;
block.item = replace(block.item, 'gm')(/bull/g, block.bullet)();

block.list = replace(block.list)(/bull/g, block.bullet)('hr', '\\n+(?=\\1?(?:[-*_] *){3,}(?:\\n+|$))')('def', '\\n+(?=' + block.def.source + ')')();

block.blockquote = replace(block.blockquote)('def', block.def)();

block.paragraph = replace(block.paragraph)('hr', block.hr)('heading', block.heading)('lheading', block.lheading)('blockquote', block.blockquote)('def', block.def)();

/**
 * Normal Block Grammar
 */

block.normal = assign({}, block);

/**
 * GFM Block Grammar
 */

block.gfm = assign({}, block.normal, {
  fences: /^ *(`{3,}|~{3,})[ \.]*(\S+)? *\n([\s\S]+?)\s*\1 *(?:\n+|$)/,
  paragraph: /^/,
  heading: /^ *(#{1,6}) +([^\n]+?) *#* *(?:\n+|$)/
});

block.gfm.paragraph = replace(block.paragraph)('(?!', '(?!' + block.gfm.fences.source.replace('\\1', '\\2') + '|' + block.list.source.replace('\\1', '\\3') + '|')();

/**
 * Block Lexer
 */

function Lexer(options) {
  this.tokens = [];
  this.tokens.links = {};
  this.options = assign({}, options || defaults);
  this.rules = block.normal;

  if (this.options.gfm) {
    this.rules = block.gfm;
  }
}

/**
 * Expose Block Rules
 */

Lexer.rules = block;

/**
 * Static Lex Method
 */

Lexer.parse = function (src, options) {
  var lexer = new Lexer(options);
  return lexer.parse(src);
};

/**
 * Preprocessing
 */

Lexer.prototype.parse = function (src) {
  src = src.replace(/\r\n|\r/g, '\n').replace(/\t/g, '    ').replace(/\u00a0/g, ' ').replace(/\u2424/g, '\n');

  return this.token(src, true);
};

/**
 * Lexing
 */

Lexer.prototype.token = function (src, top, bq) {
  var next;
  var loose;
  var cap;
  var bull;
  var b;
  var item;
  var space;
  var i;
  var l;

  src = src.replace(/^ +$/gm, '');

  while (src) {
    // newline
    if (cap = this.rules.newline.exec(src)) {
      src = src.substring(cap[0].length);
      if (cap[0].length > 1) {
        this.tokens.push({
          type: 'space'
        });
      }
    }

    // code
    if (cap = this.rules.code.exec(src)) {
      src = src.substring(cap[0].length);
      cap = cap[0].replace(/^ {4}/gm, '');
      this.tokens.push({
        type: 'code',
        text: !this.options.pedantic ? cap.replace(/\n+$/, '') : cap
      });
      continue;
    }

    // fences (gfm)
    if (cap = this.rules.fences.exec(src)) {
      src = src.substring(cap[0].length);
      this.tokens.push({
        type: 'code',
        lang: cap[2],
        text: cap[3]
      });
      continue;
    }

    // heading
    if (cap = this.rules.heading.exec(src)) {
      src = src.substring(cap[0].length);
      if (this.options.headings) {
        this.tokens.push({
          type: 'heading',
          depth: cap[1].length,
          text: cap[2]
        });
      } else {
        this.tokens.push({
          type: 'paragraph',
          text: cap[0]
        });
      }

      continue;
    }

    // lheading
    if (cap = this.rules.lheading.exec(src)) {
      src = src.substring(cap[0].length);
      this.tokens.push({
        type: 'heading',
        depth: cap[2] === '=' ? 1 : 2,
        text: cap[1]
      });
      continue;
    }

    // hr
    if (cap = this.rules.hr.exec(src)) {
      src = src.substring(cap[0].length);
      this.tokens.push({
        type: 'hr'
      });
      continue;
    }

    // blockquote
    if (cap = this.rules.blockquote.exec(src)) {
      src = src.substring(cap[0].length);

      this.tokens.push({
        type: 'blockquote_start'
      });

      cap = cap[0].replace(/^ *> ?/gm, '');

      // Pass `top` to keep the current
      // "toplevel" state. This is exactly
      // how markdown.pl works.
      this.token(cap, top, true);

      this.tokens.push({
        type: 'blockquote_end'
      });

      continue;
    }

    // list
    if (cap = this.rules.list.exec(src)) {
      src = src.substring(cap[0].length);
      bull = cap[2];

      this.tokens.push({
        type: 'list_start',
        ordered: bull.length > 1
      });

      // Get each top-level item.
      cap = cap[0].match(this.rules.item);

      next = false;
      l = cap.length;
      i = 0;

      for (; i < l; i++) {
        item = cap[i];

        // Remove the list item's bullet
        // so it is seen as the next token.
        space = item.length;
        item = item.replace(/^ *([*+-]|\d+\.) +/, '');

        // Outdent whatever the
        // list item contains. Hacky.
        if (~item.indexOf('\n ')) {
          space -= item.length;
          item = !this.options.pedantic ? item.replace(new RegExp('^ {1,' + space + '}', 'gm'), '') : item.replace(/^ {1,4}/gm, '');
        }

        // Determine whether the next list item belongs here.
        // Backpedal if it does not belong in this list.
        if (this.options.smartLists && i !== l - 1) {
          b = block.bullet.exec(cap[i + 1])[0];
          if (bull !== b && !(bull.length > 1 && b.length > 1)) {
            src = cap.slice(i + 1).join('\n') + src;
            i = l - 1;
          }
        }

        // Determine whether item is loose or not.
        // Use: /(^|\n)(?! )[^\n]+\n\n(?!\s*$)/
        // for discount behavior.
        loose = next || /\n\n(?!\s*$)/.test(item);
        if (i !== l - 1) {
          next = item.charAt(item.length - 1) === '\n';
          if (!loose) {
            loose = next;
          }
        }

        this.tokens.push({
          type: loose ? 'loose_item_start' : 'list_item_start'
        });

        // Recurse.
        this.token(item, false, bq);

        this.tokens.push({
          type: 'list_item_end'
        });
      }

      this.tokens.push({
        type: 'list_end'
      });

      continue;
    }

    // def
    if (!bq && top && (cap = this.rules.def.exec(src))) {
      src = src.substring(cap[0].length);
      this.tokens.links[cap[1].toLowerCase()] = {
        href: cap[2],
        title: cap[3]
      };
      continue;
    }

    // top-level paragraph
    if (top && (cap = this.rules.paragraph.exec(src))) {
      src = src.substring(cap[0].length);
      this.tokens.push({
        type: 'paragraph',
        text: cap[1].charAt(cap[1].length - 1) === '\n' ? cap[1].slice(0, -1) : cap[1]
      });
      continue;
    }

    // text
    if (cap = this.rules.text.exec(src)) {
      // Top-level should never reach here.
      src = src.substring(cap[0].length);
      this.tokens.push({
        type: 'text',
        text: cap[0]
      });
      continue;
    }

    if (src) {
      throw new Error('Infinite loop on byte: ' + src.charCodeAt(0));
    }
  }

  return this.tokens;
};

/**
 * Inline-Level Grammar
 */

var inline = {
  escape: /^\\([\\`*{}\[\]()#+\-.!_>])/,
  link: /^!?\[(inside)\]\(href\)/,
  reflink: /^!?\[(inside)\]\s*\[([^\]]*)\]/,
  nolink: /^!?\[((?:\[[^\]]*\]|[^\[\]])*)\]/,
  strong: /^__([\s\S]+?)__(?!_)|^\*\*([\s\S]+?)\*\*(?!\*)/,
  em: /^\b_((?:__|[\s\S])+?)_\b|^\*((?:\*\*|[\s\S])+?)\*(?!\*)/,
  code: /^(`+)\s*([\s\S]*?[^`])\s*\1(?!`)/,
  br: /^ {2,}\n(?!\s*$)/,
  del: noop,
  ins: noop,
  text: /^[\s\S]+?(?=[\\<!\[_*`]| {2,}\n|$)/
};

inline._inside = /(?:\[[^\]]*\]|[^\[\]]|\](?=[^\[]*\]))*/;
inline._href = /\s*<?([\s\S]*?)>?(?:\s+['"]([\s\S]*?)['"])?\s*/;

inline.link = replace(inline.link)('inside', inline._inside)('href', inline._href)();

inline.reflink = replace(inline.reflink)('inside', inline._inside)();

/**
 * Normal Inline Grammar
 */

inline.normal = assign({}, inline);

/**
 * Pedantic Inline Grammar
 */

inline.pedantic = assign({}, inline.normal, {
  strong: /^__(?=\S)([\s\S]*?\S)__(?!_)|^\*\*(?=\S)([\s\S]*?\S)\*\*(?!\*)/,
  em: /^_(?=\S)([\s\S]*?\S)_(?!_)|^\*(?=\S)([\s\S]*?\S)\*(?!\*)/
});

/**
 * GFM Inline Grammar
 */

inline.gfm = assign({}, inline.normal, {
  escape: replace(inline.escape)('])', '~|])')(),
  del: /^~~(?=\S)([\s\S]*?\S)~~/,
  ins: /^\+\+(?=\S)([\s\S]*?\S)\+\+/,
  text: replace(inline.text)(']|', '~+]|')()
});

/**
 * GFM + Line Breaks Inline Grammar
 */

inline.breaks = assign({}, inline.gfm, {
  br: replace(inline.br)('{2,}', '*')(),
  text: replace(inline.gfm.text)('{2,}', '*')()
});

/**
 * Inline Lexer & Compiler
 */

function InlineLexer(links, options) {
  this.options = assign({}, options || defaults);
  this.links = links;
  this.rules = inline.normal;
  this.renderer = this.options.renderer || new Renderer();
  this.renderer.options = this.options;

  if (!this.links) {
    throw new Error('Tokens array requires a `links` property.');
  }

  if (this.options.gfm) {
    if (this.options.breaks) {
      this.rules = inline.breaks;
    } else {
      this.rules = inline.gfm;
    }
  } else if (this.options.pedantic) {
    this.rules = inline.pedantic;
  }
}

/**
 * Expose Inline Rules
 */

InlineLexer.rules = inline;

/**
 * Static Lexing/Compiling Method
 */

InlineLexer.parse = function (src, links, options) {
  var inline = new InlineLexer(links, options);
  return inline.parse(src);
};

/**
 * Lexing/Compiling
 */

InlineLexer.prototype.parse = function (src) {
  var out = new _syntheticDom2.FragmentNode();
  var link;
  var cap;

  while (src) {
    // escape
    if (cap = this.rules.escape.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(new _syntheticDom2.TextNode(cap[1]));
      continue;
    }

    // link
    if (cap = this.rules.link.exec(src)) {
      src = src.substring(cap[0].length);
      this.inLink = true;
      out.appendChild(this.outputLink(cap, { href: cap[2], title: cap[3] }));
      this.inLink = false;
      continue;
    }

    // reflink, nolink
    if ((cap = this.rules.reflink.exec(src)) || (cap = this.rules.nolink.exec(src))) {
      src = src.substring(cap[0].length);
      link = (cap[2] || cap[1]).replace(/\s+/g, ' ');
      link = this.links[link.toLowerCase()];
      if (!link || !link.href) {
        out.appendChild(new _syntheticDom2.TextNode(cap[0].charAt(0)));
        src = cap[0].substring(1) + src;
        continue;
      }
      this.inLink = true;
      out.appendChild(this.outputLink(cap, link));
      this.inLink = false;
      continue;
    }

    // strong
    if (cap = this.rules.strong.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(this.renderer.strong(this.parse(cap[2] || cap[1])));
      continue;
    }

    // em
    if (cap = this.rules.em.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(this.renderer.em(this.parse(cap[2] || cap[1])));
      continue;
    }

    // code
    if (cap = this.rules.code.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(this.renderer.codespan(cap[2]));
      continue;
    }

    // br
    if (cap = this.rules.br.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(this.renderer.br());
      continue;
    }

    // del (gfm)
    if (cap = this.rules.del.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(this.renderer.del(this.parse(cap[1])));
      continue;
    }

    // ins (gfm extended)
    if (cap = this.rules.ins.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(this.renderer.ins(this.parse(cap[1])));
      continue;
    }

    // text
    if (cap = this.rules.text.exec(src)) {
      src = src.substring(cap[0].length);
      out.appendChild(this.renderer.text(new _syntheticDom2.TextNode(cap[0])));
      continue;
    }

    if (src) {
      throw new Error('Infinite loop on byte: ' + src.charCodeAt(0));
    }
  }

  return out;
};

/**
 * Compile Link
 */

InlineLexer.prototype.outputLink = function (cap, link) {
  var href = link.href;
  var title = link.title;

  return cap[0].charAt(0) !== '!' ? this.renderer.link(href, title, this.parse(cap[1])) : this.renderer.image(href, title, cap[1]);
};

/**
 * Renderer
 */

function Renderer(options) {
  this.options = options || {};
}

Renderer.prototype.code = function (childNode, lang) {
  var attributes = [];
  if (lang) {
    attributes.push({ name: 'class', value: this.options.langPrefix + lang });
  }
  var codeNode = new _syntheticDom2.ElementNode('code', attributes, [childNode]);
  return new _syntheticDom2.ElementNode('pre', [], [codeNode]);
};

Renderer.prototype.blockquote = function (childNode) {
  return new _syntheticDom2.ElementNode('blockquote', [], [childNode]);
};

Renderer.prototype.heading = function (childNode, level) {
  return new _syntheticDom2.ElementNode('h' + level, [], [childNode]);
};

Renderer.prototype.hr = function () {
  return new _syntheticDom2.ElementNode('hr', [], _syntheticDom2.SELF_CLOSING);
};

Renderer.prototype.list = function (childNode, isOrdered) {
  return new _syntheticDom2.ElementNode(isOrdered ? 'ol' : 'ul', [], [childNode]);
};

Renderer.prototype.listitem = function (childNode) {
  return new _syntheticDom2.ElementNode('li', [], [childNode]);
};

Renderer.prototype.paragraph = function (childNode) {
  return new _syntheticDom2.ElementNode('p', [], [childNode]);
};

// span level renderer
Renderer.prototype.strong = function (childNode) {
  return new _syntheticDom2.ElementNode('strong', [], [childNode]);
};

Renderer.prototype.em = function (childNode) {
  return new _syntheticDom2.ElementNode('em', [], [childNode]);
};

Renderer.prototype.codespan = function (text) {
  return new _syntheticDom2.ElementNode('code', [], [new _syntheticDom2.TextNode(text)]);
};

Renderer.prototype.br = function () {
  return new _syntheticDom2.ElementNode('br', [], _syntheticDom2.SELF_CLOSING);
};

Renderer.prototype.del = function (childNode) {
  return new _syntheticDom2.ElementNode('del', [], [childNode]);
};

Renderer.prototype.ins = function (childNode) {
  if (this.options.underlines) {
    return new _syntheticDom.ElementNode('ins', [], [childNode]);
  } else {
    return childNode;
  }
};

Renderer.prototype.link = function (href, title, childNode) {
  var attributes = [{ name: 'href', value: href }];
  if (title) {
    attributes.push({ name: 'title', value: title });
  }
  return new _syntheticDom2.ElementNode('a', attributes, [childNode]);
};

Renderer.prototype.image = function (href, title, alt) {
  var attributes = [{ name: 'src', value: href }];
  if (title) {
    attributes.push({ name: 'title', value: title });
  }
  if (alt) {
    attributes.push({ name: 'alt', value: alt });
  }
  return new _syntheticDom2.ElementNode('img', attributes, _syntheticDom2.SELF_CLOSING);
};

Renderer.prototype.text = function (childNode) {
  return childNode;
};

/**
 * Parsing & Compiling
 */

function Parser(options) {
  this.tokens = [];
  this.token = null;
  this.options = assign({}, options || defaults);
  this.options.renderer = this.options.renderer || new Renderer();
  this.renderer = this.options.renderer;
  this.renderer.options = this.options;
}

/**
 * Static Parse Method
 */

Parser.parse = function (src, options, renderer) {
  var parser = new Parser(options, renderer);
  return parser.parse(src);
};

/**
 * Parse Loop
 */

Parser.prototype.parse = function (src) {
  this.inline = new InlineLexer(src.links, this.options, this.renderer);
  this.tokens = src.slice().reverse();

  var out = new _syntheticDom2.FragmentNode();
  while (this.next()) {
    out.appendChild(this.tok());
  }

  return out;
};

/**
 * Next Token
 */

Parser.prototype.next = function () {
  return this.token = this.tokens.pop();
};

/**
 * Preview Next Token
 */

Parser.prototype.peek = function () {
  return this.tokens[this.tokens.length - 1] || 0;
};

/**
 * Parse Text Tokens
 */

Parser.prototype.parseText = function () {
  var body = this.token.text;

  while (this.peek().type === 'text') {
    body += '\n' + this.next().text;
  }

  return this.inline.parse(body);
};

/**
 * Parse Current Token
 */

Parser.prototype.tok = function () {
  switch (this.token.type) {
    case 'space':
      {
        return new _syntheticDom2.TextNode('');
      }
    case 'hr':
      {
        return this.renderer.hr();
      }
    case 'heading':
      {
        return this.renderer.heading(this.inline.parse(this.token.text), this.token.depth);
      }
    case 'code':
      {
        return this.renderer.code(this.token.text, this.token.lang);
      }
    case 'blockquote_start':
      {
        var body = new _syntheticDom2.FragmentNode();

        while (this.next().type !== 'blockquote_end') {
          body.appendChild(this.tok());
        }

        return this.renderer.blockquote(body);
      }
    case 'list_start':
      {
        var _body = new _syntheticDom2.FragmentNode();
        var ordered = this.token.ordered;

        while (this.next().type !== 'list_end') {
          _body.appendChild(this.tok());
        }

        return this.renderer.list(_body, ordered);
      }
    case 'list_item_start':
      {
        var _body2 = new _syntheticDom2.FragmentNode();

        while (this.next().type !== 'list_item_end') {
          _body2.appendChild(this.token.type === 'text' ? this.parseText() : this.tok());
        }

        return this.renderer.listitem(_body2);
      }
    case 'loose_item_start':
      {
        var _body3 = new _syntheticDom2.FragmentNode();

        while (this.next().type !== 'list_item_end') {
          _body3.appendChild(this.tok());
        }

        return this.renderer.listitem(_body3);
      }
    case 'paragraph':
      {
        return this.renderer.paragraph(this.inline.parse(this.token.text));
      }
    case 'text':
      {
        return this.renderer.paragraph(this.parseText());
      }
  }
};

/**
 * Helpers
 */

function replace(regex, options) {
  regex = regex.source;
  options = options || '';
  return function self(name, val) {
    if (!name) {
      return new RegExp(regex, options);
    }
    val = val.source || val;
    val = val.replace(/(^|[^\[])\^/g, '$1');
    regex = regex.replace(name, val);
    return self;
  };
}

var MarkdownParser = {
  parse: function parse(src, options) {
    options = assign({}, defaults, options);
    try {
      var fragment = Parser.parse(Lexer.parse(src, options), options);
    } catch (e) {
      if (options.silent) {
        fragment = new _syntheticDom2.FragmentNode([new _syntheticDom2.ElementNode('p', [], [new _syntheticDom2.TextNode('An error occured:')]), new _syntheticDom2.ElementNode('pre', [], [new _syntheticDom2.TextNode(e.message)])]);
      } else {
        throw e;
      }
    }
    if (options.getAST) {
      return new _syntheticDom2.ElementNode('body', [], [fragment]);
    } else {
      return fragment.toString(this.options.xhtml);
    }
  }
};

exports.default = MarkdownParser;