How can we keep OpenX from blocking page load?

Question

We're using OpenX to serve ads on a number of sites. If the OpenX server has problems, however, it blocks page loads on these sites. I'd rather have the sites fail gracefully, i.e. load the pages without the ads and fill them in when they become available.

We're using OpenX's single page call, and we're giving divs explicit size in CSS so they can be laid out without their contents, but still loading the script blocks page load. Are there other best practices for speeding up pages with OpenX?

Answer 1

We load our ads in iframes to avoid the problem you're having. We size div and the iframe the same, with the iframe pointing to a page which just contains the ad snippet (you can pass the zone and other required options as parameters to that page).

cheers

Lee

Answer 2

We lazy-load OpenX's code. Instead of putting the single-page call at the top of the page, we put it at the bottom. After the page has loaded, the call will get the banner data and a custom code will add the correct banners in the correct zones.

The code below requires a proper DOM. If you have jQuery, DOMAssistant, FlowJS, etc, the DOM should be fixed for you. This code will work with normal banners with images, flash, or HTML content. It may not work in some cases like when using banners from external providers (adform, etc). For that you may need to hack the code a bit.

How to use it?

1. add your SinglePageCall code towards the end of your HTML code
2. add this code under the SPC code.
3. after half a second or so, your OpenX code should be ready, and the code below will put the banners within the specified DIVs.
4. Oh, yeah, you need to add to your HTML code some DIVs as place holders for your banners. By default I have these banners set with CSS class "hidden" which totally hides the DIVs (with visibility, display, and height). Then, after the banner in a given DIV is successfully loaded, we remove the hidden class and the DIV (and the banner within) become visible.

Use at your own risk! :) Hope it helps

(function(){
if (!document || !document.getElementById || !document.addEventListener || !document.removeClass) {
return; // No proper DOM; give up.
}
var openx_timeout = 1, // limit the time we wait for openx
oZones = new Object(), // list of [div_id] => zoneID
displayBannerAds; // function.


// oZones.<divID> = <zoneID>
// eg: oZones.banner_below_job2 = 100;
// (generated on the server side with PHP)
oZones.banner_top = 23;
oZones.banner_bottom = 34;



displayBannerAds = function(){
if( typeof(OA_output)!='undefined' && OA_output.constructor == Array ){
  // OpenX SinglePageCall ready!

  if (OA_output.length>0) {

    for (var zone_div_id in oZones){
      zoneid = oZones[zone_div_id];

      if(typeof(OA_output[zoneid])!='undefined' && OA_output[zoneid]!='') {

        var flashCode,
          oDIV = document.getElementById( zone_div_id );

        if (oDIV) {

          // if it's a flash banner..
          if(OA_output[zoneid].indexOf("ox_swf.write")!=-1)
          {

            // extract javascript code
            var pre_code_wrap = "<script type='text/javascript'><!--// <![CDATA[",
              post_code_wrap = "// ]]> -->";

            flashCode = OA_output[zoneid].substr(OA_output[zoneid].indexOf(pre_code_wrap)+pre_code_wrap.length);
            flashCode = flashCode.substr(0, flashCode.indexOf(post_code_wrap));


            // replace destination for the SWFObject
            flashCode = flashCode.replace(/ox\_swf\.write\(\'(.*)'\)/, "ox_swf.write('"+ oDIV.id +"')");


            // insert SWFObject
            if( flashCode.indexOf("ox_swf.write")!=-1 ){
              eval(flashCode);
              oDIV.removeClass('hidden');
            }// else: the code was not as expected; don't show it


          }else{
            // normal image banner; just set the contents of the DIV
            oDIV.innerHTML = OA_output[zoneid];
            oDIV.removeClass('hidden');
          }
        }
      }
    } // end of loop
  }//else: no banners on this page
}else{
  // not ready, let's wait a bit
  if (openx_timeout>80) {
    return; // we waited too long; abort
  };
  setTimeout( displayBannerAds, 10*openx_timeout );
   openx_timeout+=4;
}
};
displayBannerAds();
})();