markdown-it/lib/rules_block/html_block.js

// HTML block

'use strict';


var block_names = require('../common/html_blocks');
var HTML_OPEN_CLOSE_TAG_RE = require('../common/html_re').HTML_OPEN_CLOSE_TAG_RE;

// An array of opening and corresponding closing sequences for html tags,
// last argument defines whether it can terminate a paragraph or not
//
var HTML_SEQUENCES = [
  [ /^<(script|pre|style|textarea)(?=(\s|>|$))/i, /<\/(script|pre|style|textarea)>/i, true ],
  [ /^<!--/,        /-->/,   true ],
  [ /^<\?/,         /\?>/,   true ],
  [ /^<![A-Z]/,     />/,     true ],
  [ /^<!\[CDATA\[/, /\]\]>/, true ],
  [ new RegExp('^</?(' + block_names.join('|') + ')(?=(\\s|/?>|$))', 'i'), /^$/, true ],
  [ new RegExp(HTML_OPEN_CLOSE_TAG_RE.source + '\\s*$'),  /^$/, false ]
];


module.exports = function html_block(state, startLine, endLine, silent) {
  var i, nextLine, token, lineText,
      pos = state.bMarks[startLine] + state.tShift[startLine],
      max = state.eMarks[startLine];

  // if it's indented more than 3 spaces, it should be a code block
  if (state.sCount[startLine] - state.blkIndent >= 4) { return false; }

  if (!state.md.options.html) { return false; }

  if (state.src.charCodeAt(pos) !== 0x3C/* < */) { return false; }

  lineText = state.src.slice(pos, max);

  for (i = 0; i < HTML_SEQUENCES.length; i++) {
    if (HTML_SEQUENCES[i][0].test(lineText)) { break; }
  }

  if (i === HTML_SEQUENCES.length) { return false; }

  if (silent) {
    // true if this sequence can be a terminator, false otherwise
    return HTML_SEQUENCES[i][2];
  }

  nextLine = startLine + 1;

  // If we are here - we detected HTML block.
  // Let's roll down till block end.
  if (!HTML_SEQUENCES[i][1].test(lineText)) {
    for (; nextLine < endLine; nextLine++) {
      if (state.sCount[nextLine] < state.blkIndent) { break; }

      pos = state.bMarks[nextLine] + state.tShift[nextLine];
      max = state.eMarks[nextLine];
      lineText = state.src.slice(pos, max);

      if (HTML_SEQUENCES[i][1].test(lineText)) {
        if (lineText.length !== 0) { nextLine++; }
        break;
      }
    }
  }

  state.line = nextLine;

  token         = state.push('html_block', '', 0);
  token.map     = [ startLine, nextLine ];
  token.content = state.getLines(startLine, nextLine, state.blkIndent, true);

  return true;
};