jQuery .ready in a dynamically inserted iframe

Question

We are using jQuery thickbox to dynamically display an iframe when someone clicks on a picture. In this iframe, we are using galleria a javascript library to display multiple pictures.

The problem seems to be that $(document).ready in the iframe seems to be fired too soon and the iframe content isn't even loaded yet, so galleria code is not applied properly on the DOM elements. $(document).ready seems to use the iframe parent ready state to decide if the iframe is ready.

If we extract the function called by document ready in a separate function and call it after a timeout of 100 ms. It works, but we can't take the chance in production with a slow computer.

$(document).ready(function() { setTimeout(ApplyGalleria, 100); });

My question: which jQuery event should we bind to to be able to execute our code when the dynamic iframe is ready and not just it's a parent?

Answer 1

Using jQuery 1.3.2 the following worked for me:

$('iframe').ready(function() {
  $('body', $('iframe').contents()).html('Hello World!');
});

REVISION:! Actually the above code sometimes looks like it works in Firefox, never looks like it works in Opera.

Instead I implemented a polling solution for my purposes. Simplified down it looks like this:

$(function() {
  function manipIframe() {
    el = $('body', $('iframe').contents());
    if (el.length != 1) {
      setTimeout(manipIframe, 100);
      return;
    }
    el.html('Hello World!');
  }
  manipIframe();
});

This doesn't require code in the called iframe pages. All code resides and executes from the parent frame/window.

Answer 2

Following DrJokepu's and David Murdoch idea I implemented a more complete version. It requires jQuery on both the parent and iframe and the iframe to be in your control.

iframe code:

var iframe = window.frameElement;

if (iframe){
    iframe.contentDocument = document;//normalization: some browsers don't set the contentDocument, only the contentWindow

    var parent = window.parent;
    $(parent.document).ready(function(){//wait for parent to make sure it has jQuery ready
        var parent$ = parent.jQuery;

        parent$(iframe).trigger("iframeloading");

        $(function(){
            parent$(iframe).trigger("iframeready");
        });

        $(window).load(function(){//kind of unnecessary, but here for completion
            parent$(iframe).trigger("iframeloaded");
        });

        $(window).unload(function(e){//not possible to prevent default
            parent$(iframe).trigger("iframeunloaded");
        });

        $(window).on("beforeunload",function(){
            parent$(iframe).trigger("iframebeforeunload");
        });
    });
}

parent test code:

$(function(){
    $("iframe").on("iframeloading iframeready iframeloaded iframebeforeunload iframeunloaded", function(e){
        console.log(e.type);
    });
});

Answer 3

Basically what others have already posted but IMHO a bit cleaner:

$('<iframe/>', {
    src: 'https://example.com/',
    load: function() {
        alert("loaded")
    }
}).appendTo('body');

Answer 4

This was the exact issue I ran into with our client. I created a little jquery plugin that seems to work for iframe readiness. It uses polling to check the iframe document readyState combined with the inner document url combined with the iframe source to make sure the iframe is in fact "ready".

The issue with "onload" is that you need access to the actual iframe being added to the DOM, if you don't then you need to try to catch the iframe loading which if it is cached then you may not. What I needed was a script that could be called anytime, and determine whether or not the iframe was "ready" or not.

Here's the question:

Holy grail for determining whether or not local iframe has loaded

and here's the jsfiddle I eventually came up with.

https://jsfiddle.net/q0smjkh5/10/

In the jsfiddle above, I am waiting for onload to append an iframe to the dom, then checking iframe's inner document's ready state - which should be cross domain because it's pointed to wikipedia - but Chrome seems to report "complete". The plug-in's iready method then gets called when the iframe is in fact ready. The callback tries to check the inner document's ready state again - this time reporting a cross domain request (which is correct) - anyway it seems to work for what I need and hope it helps others.

<script>
  (function($, document, undefined) {
    $.fn["iready"] = function(callback) {
      var ifr = this.filter("iframe"),
          arg = arguments,
          src = this,
          clc = null, // collection
          lng = 50,   // length of time to wait between intervals
          ivl = -1,   // interval id
          chk = function(ifr) {
            try {
              var cnt = ifr.contents(),
                  doc = cnt[0],
                  src = ifr.attr("src"),
                  url = doc.URL;
              switch (doc.readyState) {
                case "complete":
                  if (!src || src === "about:blank") {
                    // we don't care about empty iframes
                    ifr.data("ready", "true");
                  } else if (!url || url === "about:blank") {
                    // empty document still needs loaded
                    ifr.data("ready", undefined);
                  } else {
                    // not an empty iframe and not an empty src
                    // should be loaded
                    ifr.data("ready", true);
                  }

                  break;
                case "interactive":
                  ifr.data("ready", "true");
                  break;
                case "loading":
                default:
                  // still loading
                  break;   
              }
            } catch (ignore) {
              // as far as we're concerned the iframe is ready
              // since we won't be able to access it cross domain
              ifr.data("ready", "true");
            }

            return ifr.data("ready") === "true";
          };

      if (ifr.length) {
        ifr.each(function() {
          if (!$(this).data("ready")) {
            // add to collection
            clc = (clc) ? clc.add($(this)) : $(this);
          }
        });
        if (clc) {
          ivl = setInterval(function() {
            var rd = true;
            clc.each(function() {
              if (!$(this).data("ready")) {
                if (!chk($(this))) {
                  rd = false;
                }
              }
            });

            if (rd) {
              clearInterval(ivl);
              clc = null;
              callback.apply(src, arg);
            }
          }, lng);
        } else {
          clc = null;
          callback.apply(src, arg);
        }
      } else {
        clc = null;
        callback.apply(this, arguments);
      }
      return this;
    };
  }(jQuery, document));
</script>

Answer 5

Try this,

<iframe id="testframe" src="about:blank" onload="if (testframe.location.href != 'about:blank') testframe_loaded()"></iframe>

All you need to do then is create the JavaScript function testframe_loaded().

Answer 6

I'm loading the PDF with jQuery ajax into browser cache. Then I create embedded element with data already in browser cache. I guess it will work with iframe too.

var url = "http://example.com/my.pdf";
// show spinner
$.mobile.showPageLoadingMsg('b', note, false);
$.ajax({
    url: url,
    cache: true,
    mimeType: 'application/pdf',
    success: function () {
        // display cached data
        $(scroller).append('<embed type="application/pdf" src="' + url + '" />');
        // hide spinner
        $.mobile.hidePageLoadingMsg();
    }
});

You have to set your http headers correctly as well.

HttpContext.Response.Expires = 1;
HttpContext.Response.Cache.SetNoServerCaching();
HttpContext.Response.Cache.SetAllowResponseInBrowserHistory(false);
HttpContext.Response.CacheControl = "Private";