execute_script_tags : load & execute script tags inside content loaded with ajax

execute_script_tags.js

A17.Helpers.execute_script_tags = function(container) {
  var loaded = false;
  var progress = 0;
  var $container = $(container);

  var current_script = null;
  var head = document.getElementsByTagName('head')[0] || document.body;
  var new_scripts_to_load = $('script[src]', $container);
  var new_scripts_to_eval = $('script:not([src])', $container);
  var existing_scripts = $('script[src]', $(head));

  if(new_scripts_to_load.length) {
    if(progress < new_scripts_to_load.length) startLoad(new_scripts_to_load[progress]);
  }

  function startLoad(target) {
    loaded = false;

    var $target = $(target);
    var src = target.src;

    var matchedScripts = existing_scripts.filter(function() {
      return target.src === src;
    })
    if (matchedScripts.length) {
      matchedScripts.remove();
    }

    var script = document.createElement('script');
    current_script = script;

    if (typeof($target.attr('type')) !== "undefined") {
      script.type = $target.attr('type');
    }

    script.src = $target.attr('src');
    script.onload = handleLoad;
    script.onreadystatechange = handleReadyStateChange;
    script.onerror = handleError;

    head.appendChild(script);
  };

  function handleLoad() {
    if (!loaded) continueLoading();
  }

  function handleReadyStateChange() {
    var state;

    if (!loaded) {
      state = current_script.readyState;
      if (state === "complete") handleLoad();
    }
  }
  function handleError() {
    if (!loaded) continueLoading();
  }

  function continueLoading() {
    loaded = true;
    progress++;
    if(progress < new_scripts_to_load.length) startLoad(new_scripts_to_load[progress]);
    else if(new_scripts_to_eval.length) evalScripts();
  }

  function evalScripts() {
    new_scripts_to_eval.each(function() {
        var target = this;

        var script = document.createElement('script');
        script.text = target.textContent;

        // Place the scripts in the head instead of the body to avoid errors
        // when called from the head in the first place.
        head.appendChild(script);

        // Remove scripts afterwards to avoid unnecessary increased DOM size.
        head.removeChild(script);
    });
  }
};