How to Make an Ad Server in Javascript

Google uses javascript to at least invoke the ad server, if not to actually serve the ads... I have no idea what's behind their show_ads.js javascript, but it clearly is javascript being called.

Here's a typical adsense call:

<script type="text/javascript"><!--
google_ad_client = "pub-xxxxxxxx";
google_ad_slot = "yyyyyyyyy";
google_ad_width = 300;
google_ad_height = 250;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>

Moderator,

This question is not drawing expert comments.  Do you have any suggestions ?

Server script would be a key to this.  Can your Linux server support one (e.g. ASP, PHP, .NET, Perl)?  Most likely not the first or third but PHP would be nice and is pretty common on Linux servers.

Cookies will be an important part of this.  They don't require server script but would be the only way to have the server know what the page last had (and not show the same ad twice).  Of course they run the risk of being blocked or deleted but it is what you would have to use.

As far as comparing what Google does that is how they make it work.  However the JS file in this case is probably generated by the server or works with server code.  Your browser gets the JS and sees it but the server made it.  That is why I said and agree with the expert above that server script is a key and would be most useful in this.  You don't actually need Javascript if the ad isn't rotating WHILE the page is in the browser.  If you want to minimize load, size, etc then server script also better.  When the visitor goes to the page the server script would look for the cookie, if found read the last ad done or if not then start with ad one and make the cookie, send the ad and update the cookie so it would reflect the ad sent.

Let me know how this helps or if you have a question.  I can provide details but need responses to this to know what details to provide. :)

bol

bol,

My Linux server supports PHP.

As for the Google ad server, here's the way I understand it:

When a client browser requests a page that contains the AdSense code above, the browser pulls and runs the following JS from a Google server machine:

http://pagead2.googlesyndication.com/pagead/show_ads.js

That JS (directly or indirectly) then pulls the actual ad from a server machine (could be the same server or another server machine) and displays the ad in the client browser.

You are probably right... a Google JS most likely uses PHP or ASP or some other server script to actually push the ad.  But the above JS does not do it directly... I've looked at the code... the above JS only calls other JS (i.e. no calls to .php, .asp, etc.)

So, why not just push the ad directly with PHP or ASP, etc. ?

They must have a good reason.

AdSense ads don't rotate unless you reload the page, and even then, often times they don't rotate even IF you reload the page.

So I don't think they're using JS because they need to rotate ads while the page is in the browser (i.e. to rotate ads without the client requesting a reload, or a new page.)

We can talk about PHP later, but for now, why do you think AdSense relies so heavily on JS ?

>> why do you think AdSense relies so heavily on JS ? <<

Hopefully my response to this will answer all of the other things.  It seems like some of my other stuff was ignored but, if that isn't key to answering this, then that doesn't matter and I don't need a response to it.

You said you looked at the code but that doesn't really mean much.  If you have used server scripts then you know they just send to the browser what you want them to send.  Using view source only shows the part of it.  An example of this is one page that shows a form, processes the form info, sends the email, and provides a thanks.  You might see 2 completely different web pages depending on the step.  However it can be done by one server page (i.e. the URL won't change).

The same can be done for files that don't end with a normal server side script extension.  In other words the file doesn't have to end with .asp, .aspx, .php, or .jsp to be a product of a server script.  EE is an example of this.  Their pages end with .html but are definitely not just static html pages.  All that needs to be done is have the server set up to process that file or extension.

I can't say for sure but am almost positive Google does this for the JS page.  It is the only way to have a dynamic JS page and what you see sounds dynamic.  You mentioned a "push" but that isn't really an option and involves some specific and special server set up and technology.  It definitely would not be efficient or needed for something like what you ask here.  ASP can't even do it.  PHP can with sockets I believe but it just would be overkill.

I didn't make this clear before because it seemed off topic for what you were asking.  From your response it seems I may have misread what you wanted.  The reason Google even provides the JS file is probably just because it needs to be something third party sites can use.  Since you are talking about ads just for your server and domain this isn't needed.  The JS file is handy when other domains need to access your "files" because without them including the JS file the browser won't allow the "cross domain scripting."

I hope this helps and covers what you are asking.  Let me know if you have a question on any of this.

bol

bol,

Thanks for the detailed answer... I was curious about how AdSense serves ads, and about their use of JS.  Your point about cross domain scripting may be the key to why AdSense uses the .js extension on its script.

However, regarding my original question, I recognize that the AdSense approach is not necessary, and perhaps not even desirable, if it can be done with PHP on the same server (i.e. page, script, and ads all reside on the same server.)

However, for completion, I attached the AdSense JS, which comes from the above link, and I welcome your comments on it.

Also, please comment on a PHP solution to my original question, if you're so inclined.

Also... previously, I should have said "serve" the ad... not "push" the ad.

I recognize that push and pull technologies are different, and I wasn't trying the mix the two.

Just a mental lapse :)

I will post a PHP script example of how to do this since that was what you asked here.  The experts above have shown good examples of how to do this in Javascript.  Let me know if you have a question about the code or how to use it.  I added comments so it should be clear but I will be glad to elaborate if something needs details or explanation.

>> I was curious about how AdSense serves ads, and about their use of JS. <<

I am glad the details in my last post helped.  However it seems they were getting off topic and the comment quoted above (plus some of the other things you asked) are also different from this thread's question.  If you would like answers to them then you should open a new question.  I can't really add more about how adsense works though so am not sure it is worth a question.  The details you want are Google's and they protect their "secrets" well.  My info on it is probably correct (at least generally) but is an educated "guess."  I appreciate you attaching the file but that topic has distracted me enough from what you asked here and I don't like to continue "guessing" (no matter how right I feel I am).

I hope the above helps.  Let me know if you have a question about anything I have said.

bol

<?php
// this code needs to be before any code that would send something to the browser
 
$aAds = Array("adFile1.gif","adFile2.gif","adFile3.gif"); // array for images used in ad
// might need other array for a URL to the ad's "site"
 
if (isset($_COOKIE['adFile'])) {
	$nAd = $_COOKIE['adFile'];
	$nAd = ($nAd * 1) + 1;
} else {
	$nAd = 0;
}
// use this line or section to make the html for the ad
//   the number from the cookie is used to determine which ad to show (from array(s))
 
$_COOKIE['adFile'] = $nAd; // write cookie
 
// rest of page with html and php sending html
                                              

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Lil, thanks for the code... the server is Apache, with Linux and PHP.

mplungjan, thanks for the code...

Both scripts implement a random ad index, using two different methods... excellent.

But if I wanted to store the ad index on the server between calls to the script... any ideas how to do that, and how to integrate the ad index (stored on the server) with your JS ?

The idea of storing the ad index on the server is to cycle through the ads in a fixed order (1,2... N, 1, 2, ...), as opposed to randomly.

bol, thanks for the code... wouldn't you need to set the cookie in the client, with something like:
setcookie("adFile",0,time()+3e6);

and increment the client cookie during each script run, with something like:
setcookie("adFile",$_COOKIE['adFile']+1,time()+3e6);

and reset the client cookie to zero again after all the ads have been exhausted ?

To cycle without server, use a cookie and not random

var idx = getCookie('adIdx')
if (idx >= myAds.length) idx = 0;
var myAd = myAds[idx];
setCookie('adIdx',++idx)

>> wouldn't you need to set the cookie in the client <<

Nothing needs to be done in client script.  The PHP script tells the browser all it needs to make the cookie.  Javascript or other clientscript isn't required.

I did have an error in what I posted though.  The part to set the cookie is wrong.  Cold brain I guess because I can't see any other excuse for it. :)

The correct line for my line 16 above is ...

setcookie("adFile", $nAd, time() + 60 * 60 * 24 * $nDays);

The $nDays variable can be replaced with the number or used above that line to set the days.  The "days" would be how many days in the future should the cookie last.  An expiration date must be set but could be 30 days, 365 days, etc.

>> and reset the client cookie to zero again after all the ads have been exhausted ? <<

I did not include something in PHP to do that but it can be done there.  Below line 9 above you would add ...

if ($nAd >= count($aAds)) $nAd = 0;

Sorry for the error.  Remember the PHP script doesn't need any Javascript so you would not use both.  Let me know if you have a question or how this helps.

bol

Just a "disclaimer" ... when I have said Javascript wasn't needed that is ONLY for what I have provided or recommended.  I am not trying to say you should not use the other's recommendation.  In their case there is no need for server script.  Personally I would always use server script for something like this but I don't want that personal opinion or the way I have phrased my responses to seem to be an argument against what the others are providing.  Which you use is up to what works best for you.  I would not combine the two though.  There is no reason or benefit to it.

bol

Thanks all...

I did recognize that it's either the JS example(s) or the PHP example, but not both (for this application.)

As to cookies, if the client browser has cookies OFF, would the JS or PHP scripts break ?

If so, please suggest the exception code to handle cookies OFF.

As to JS vs PHP (in this application)... here's the way I see the two scripts operating:

JS --
client sends page request to server
server sends page with ad_JS in it
client runs ad_JS  in the page received  (using client CPU and RAM)
client sets cookie and displays page with ad
done

PHP --
client sends page request to server
server runs ad_PHP in the page requested (using server CPU and RAM)
server sends page with an embedded ad, plus a set-cookie request
client sets cookie and displays page with ad
done

If this is correct, and if we want to minimize server load, wouldn't JS be a better choice in this case ?

I understand that server script is required for certain tasks, such as user validation, email, etc., but for this application, wouldn't JS (i.e. client script) be more appropriate ?

Other reasons for using JS instead of PHP:

No changes to the way that files are named and/or processed on the server.  

Embedding PHP into the HTML requires one of the following:
1) files with PHP embedded must be renamed .php -- but doing so breaks external links to those files.
2) the standard Apache pre-processor for .htm, .html and .shtml files must be swapped for the PHP pre-processor.

Doing either of these things, breaks certain HTML directives, such as the include directive.

Embedding JS in HTML doesn't require either of the above... the JS passes directly to the client.  No external links to server files are broken, and no HTML directives are broken in those files.

These factors, in addition to the efficiency factor I mentioned earlier, appear to be compelling reasons for using JS in the ad server.

mplungjan,

Please say whether your JS breaks when cookies are OFF.

If it does, could you please post the exception code to handle the case when cookies are OFF ?

Thanks for the help.

I'm glad I could help.  Thanks for the fun question, the grade and the points.

bol

Cheers,

Tx.

 A good idea to test if cookies are off - here is some code that might do that. Not tested

var idx = getCookie('adIdx')
if (idx == null) {
  setCookie('adIdx',0);// try
  if (getCookie('adIdx')==null) idx = Math.floor(Math.random()*myAds.length); // no cookies
}
else if (idx >= myAds.length) idx = 0;
var myAd = myAds[idx];
setCookie('adIdx',++idx)
                                              

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mplungjan,

Thanks again !

The above solution helps me If my ad is present on my web sever. But in my case My adv is displayed using a script sent by my client. I have three different script tags for three different ads.  How to integrate these scripts at runtime. I am getting these scripts from db.

can you give use more details and perhaps better: Open a new question?

Let me explain in detail.
I have two scripts.
1.
<script type='text/javascript' src='http://4virtu.placelocal.com/_js/ad.js.php?clientID=0&campaignID=5125&adWidth=300&adHeight=250&campaign_api=dispCamp.getNextCampaign&api_url=api.placelocal.com&domain_name=4virtu.placelocal.com&tracking_url=tracking.placelocal.com&tracking_parameters=&animationTime=&clickTag={clickurl}&random={random}'></script>

2.
<script type='text/javascript' src='http://4virtu.placelocal.com/_js/ad.js.php?clientID=0&campaignID=5125&adWidth=728&adHeight=90&campaign_api=dispCamp.getNextCampaign&api_url=api.placelocal.com&domain_name=4virtu.placelocal.com&tracking_url=tracking.placelocal.com&tracking_parameters=&animationTime=&clickTag={clickurl}&random={random}'></script>

If we enter these two scripts at design time into any web page under <div> tag and run we can see that these two scripts are executed. Hence we can see the ads which are running at 'http://4virtu.placelocal.com

Whereas if we try to bind these scripts at runtime to any div then unable to run the scripts. Pl suggest.
My aim is to rotate these two ads.

I would load them in an iFrame

id did not work, can pl give me code for this.