index.js

// Process ![test]( x =100x200)
//                    ^^^^^^^^ this size specification

'use strict';

var parseImageSize = require('./helpers/parse_image_size');
var normalizeReference = require('./helpers/normalize_reference.js');

function image_with_size(md) {
  return function(state, silent) {
    var code,
        href,
        label,
        labelEnd,
        labelStart,
        pos,
        ref,
        res,
        title,
        width = '',
        height = '',
        tokens,
        start,
        oldPos = state.pos,
        max = state.posMax;

    if (state.src.charCodeAt(state.pos) !== 0x21/* ! */) { return false; }
    if (state.src.charCodeAt(state.pos + 1) !== 0x5B/* [ */) { return false; }

    labelStart = state.pos + 2;
    labelEnd = md.helpers.parseLinkLabel(state, state.pos + 1, false);

    // parser failed to find ']', so it's not a valid link
    if (labelEnd < 0) { return false; }

    pos = labelEnd + 1;
    if (pos < max && state.src.charCodeAt(pos) === 0x28/* ( */) {

      //
      // Inline link
      //

      // [link](  <href>  "title"  )
      //        ^^ skipping these spaces
      pos++;
      for (; pos < max; pos++) {
        code = state.src.charCodeAt(pos);
        if (code !== 0x20 && code !== 0x0A) { break; }
      }
      if (pos >= max) { return false; }

      // [link](  <href>  "title"  )
      //          ^^^^^^ parsing link destination
      start = pos;
      res = md.helpers.parseLinkDestination(state.src, pos, state.posMax);
      if (res.ok && state.md.inline.validateLink(res.str)) {
        href = res.str;
        pos = res.pos;
      } else {
        href = '';
      }

      // [link](  <href>  "title"  )
      //                ^^ skipping these spaces
      start = pos;
      for (; pos < max; pos++) {
        code = state.src.charCodeAt(pos);
        if (code !== 0x20 && code !== 0x0A) { break; }
      }

      // [link](  <href>  "title"  )
      //                  ^^^^^^^ parsing link title
      res = md.helpers.parseLinkTitle(state.src, pos, state.posMax);
      if (pos < max && start !== pos && res.ok) {
        title = res.str;
        pos = res.pos;

        // [link](  <href>  "title"  )
        //                         ^^ skipping these spaces
        for (; pos < max; pos++) {
          code = state.src.charCodeAt(pos);
          if (code !== 0x20 && code !== 0x0A) { break; }
        }
      } else {
        title = '';
      }

      // [link](  <href>  "title" =WxH  )
      //                          ^^^^ parsing image size
      if (pos - 1 >= 0) {
        code = state.src.charCodeAt(pos - 1);

        // there must be at least one white spaces
        // between previous field and the size
        if (code === 0x20) {
          res = parseImageSize(state.src, pos, state.posMax);
          if (res.ok) {
            width = res.width;
            height = res.height;
            pos = res.pos;

            // [link](  <href>  "title" =WxH  )
            //                              ^^ skipping these spaces
            for (; pos < max; pos++) {
              code = state.src.charCodeAt(pos);
              if (code !== 0x20 && code !== 0x0A) { break; }
            }
          }
        }
      }

      if (pos >= max || state.src.charCodeAt(pos) !== 0x29/* ) */) {
        state.pos = oldPos;
        return false;
      }
      pos++;

    } else {
      //
      // Link reference
      //
      if (typeof state.env.references === 'undefined') { return false; }

      // [foo]  [bar]
      //      ^^ optional whitespace (can include newlines)
      for (; pos < max; pos++) {
        code = state.src.charCodeAt(pos);
        if (code !== 0x20 && code !== 0x0A) { break; }
      }

      if (pos < max && state.src.charCodeAt(pos) === 0x5B/* [ */) {
        start = pos + 1;
        pos = md.helpers.parseLinkLabel(state, pos);
        if (pos >= 0) {
          label = state.src.slice(start, pos++);
        } else {
          pos = labelEnd + 1;
        }
      } else {
        pos = labelEnd + 1;
      }

      // covers label === '' and label === undefined
      // (collapsed reference link and shortcut reference link respectively)
      if (!label) { label = state.src.slice(labelStart, labelEnd); }

      ref = state.env.references[normalizeReference(label)];
      if (!ref) {
        state.pos = oldPos;
        return false;
      }
      href = ref.href;
      title = ref.title;
    }

    //
    // We found the end of the link, and know for a fact it's a valid link;
    // so all that's left to do is to call tokenizer.
    //
    if (!silent) {
      state.pos = labelStart;
      state.posMax = labelEnd;

      var newState = new state.md.inline.State(
        state.src.slice(labelStart, labelEnd),
        state.md,
        state.env,
        tokens = []
      );
      newState.md.inline.tokenize(newState);

      state.push({
        type: 'imsize',
        src: href,
        title: title,
        tokens: tokens,
        level: state.level,
        width: width,
        height: height
      });
    }

    state.pos = pos;
    state.posMax = max;
    return true;
  };
}


function tokenize_imsize(md) {
  return function(tokens, idx, options, env, self) {
    var src = ' src="' + md.utils.escapeHtml(tokens[idx].src) + '"';
    var title = '';
    if (tokens[idx].title) {
      title = ' title="' + md.utils.escapeHtml(md.utils.replaceEntities(tokens[idx].title)) + '"';
    }
    var alt = ' alt="' + self.renderInlineAsText(tokens[idx].tokens, options, env) + '"';
    var width = tokens[idx].width !== '' ? ' width="' + tokens[idx].width + '"' : '';
    var height = tokens[idx].height !== '' ? ' height="' + tokens[idx].height + '"' : '';
    var size = width + height;
    var suffix = options.xhtmlOut ? ' /' : '';
    return '<img' + src + alt + title + size + suffix + '>';
  };
}

module.exports = function imsize_plugin(md) {
  md.renderer.rules.imsize = tokenize_imsize(md);
  md.inline.ruler.before('emphasis', 'imsize', image_with_size(md));
};