pad.pub0.org/static/js/plugins.js

/**
 * This code is mostly from the old Etherpad. Please help us to comment this code. 
 * This helps other people to understand this code better and helps them to improve it.
 * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
 */

plugins = {
  callHook: function(hookName, args)
  {
    var hook = clientVars.hooks[hookName];
    if (hook === undefined) return [];
    var res = [];
    for (var i = 0, N = hook.length; i < N; i++)
    {
      var plugin = hook[i];
      var pluginRes = eval(plugin.plugin)[plugin.original || hookName](args);
      if (pluginRes != undefined && pluginRes != null) res = res.concat(pluginRes);
    }
    return res;
  },

  callHookStr: function(hookName, args, sep, pre, post)
  {
    if (sep == undefined) sep = '';
    if (pre == undefined) pre = '';
    if (post == undefined) post = '';
    return plugins.callHook(hookName, args).map(function(x)
    {
      return pre + x + post
    }).join(sep || "");
  }
};