app/javascript/mastodon/emoji.js

   1 import { unicodeMapping } from './emojione_light';
   2 import Trie from 'substring-trie';
   3
   4 const trie = new Trie(Object.keys(unicodeMapping));
   5
   6 const emojify = (str, customEmojis = {}) => {
   7   let rtn = '';
   8   for (;;) {
   9     let match, i = 0, tag;
  10     while (i < str.length && (tag = '<&'.indexOf(str[i])) === -1 && str[i] !== ':' && !(match = trie.search(str.slice(i)))) {
  11       i += str.codePointAt(i) < 65536 ? 1 : 2;
  12     }
  13     if (i === str.length)
  14       break;
  15     else if (tag >= 0) {
  16       const tagend = str.indexOf('>;'[tag], i + 1) + 1;
  17       if (!tagend)
  18         break;
  19       rtn += str.slice(0, tagend);
  20       str = str.slice(tagend);
  21     } else if (str[i] === ':') {
  22       try {
  23         // if replacing :shortname: succeed, exit this block with "continue"
  24         const closeColon = str.indexOf(':', i + 1) + 1;
  25         if (!closeColon) throw null; // no pair of ':'
  26         const lt = str.indexOf('<', i + 1);
  27         if (!(lt === -1 || lt >= closeColon)) throw null; // tag appeared before closing ':'
  28         const shortname = str.slice(i, closeColon);
  29         if (shortname in customEmojis) {
  30           rtn += str.slice(0, i) + `<img draggable="false" class="emojione" alt="${shortname}" title="${shortname}" src="${customEmojis[shortname]}" />`;
  31           str = str.slice(closeColon);
  32           continue;
  33         }
  34       } catch (e) {}
  35       // replacing :shortname: failed
  36       rtn += str.slice(0, i + 1);
  37       str = str.slice(i + 1);
  38     } else {
  39       const [filename, shortCode] = unicodeMapping[match];
  40       rtn += str.slice(0, i) + `<img draggable="false" class="emojione" alt="${match}" title=":${shortCode}:" src="/emoji/${filename}.svg" />`;
  41       str = str.slice(i + match.length);
  42     }
  43   }
  44   return rtn + str;
  45 };
  46
  47 export default emojify;