Inserting Affiliate Codes Into Links and Forms
By
William
Bontrager
If you have your own affiliates,
you may wish to insert affiliate codes into links and forms. Reasons for
doing this might include
1. Tracking an affiliate code from page to page.
2. Pre-filling in an affiliate code into a form text
or hidden field, to
~~ Receive the affiliate code via email.
~~ Record the affiliate code in a database.
~~ Email an affiliate URL to someone else.
~~ Have the affiliate code available when
processing the rest of the submitted
information.
3. Redirecting the site visitor to a different page,
customized for the affiliate code.
The Web Page URL
In order to use the affiliate code in links and forms, the URL of the web
page in the user's browser must be followed by either a question mark or
a hash mark ("?" or "#") and then the affiliate code. Without those, the
JavaScript presented in this article won't have an affiliate code to
process.
Here are examples of what I mean:
http://WillMaster.com/page.html?AF33
http://WillMaster.com/page.html#AF33
In both of those examples, the affiliate code is "AF33". In one, the affiliate
code is appended to the URL with a question mark and in the other it is appended
with a hash mark.
Domain URLs (without specifying a particular web page) can also have the
affiliate code appended. Examples:
http://WillMaster.com/?AF33
http://WillMaster.com/#AF33
Notice that a slash character follows the domain name. The slash is necessary
for some browsers to properly translate the URL.
The Affiliate Code Extractor
The following eleven lines of JavaScript, when placed in the HEAD section
of your web page, will extract the affiliate code from the web page URL:
<script type="text/javascript" language="JavaScript"><!--
function GetAffiliateCode() {
var DefaultAffiliateCode = 'mydefaultcode';
var thisurl = location.href;
var ql = thisurl.indexOf('?');
if(ql < 0) { ql = thisurl.indexOf('#'); }
if(ql >= 0) { return thisurl.substr(ql + 1); }
return DefaultAffiliateCode;
}
ThisAffiliateCode = GetAffiliateCode();
//--></script>
In the third line of the above
JavaScript, you can specify a default affiliate code to use when the web
page URL doesn't provide one. If you want a blank or null affiliate code
for the default, remove all text between the two apostrophes (but keep the
apostrophes).
Line by line, the above JavaScript:
Line 1 -- Tells the browser that the following lines are
JavaScript.
Line 2 -- Begins function GetAffiliateCode().
Line 3 -- Stores a default affiliate code into variable
DefaultAffiliateCode.
Line 4 -- Stores the URL in the browser's address bar into
variable thisurl.
Line 5 -- Stores the location of the question mark in the
URL into variable ql.
Line 6 -- If the URL has no question mark, store
the location of the hash mark into variable ql.
Line 7 -- If the URL had a question mark or a hash mark,
returns all the text in the URL that follows the
mark.
Line 8 -- This line runs only if there was no question mark
or hash mark in the URL. It returns the default
affiliate code.
Line 9 -- Marks the end of function GetAffiliateCode().
Line 10 -- Runs function GetAffiliateCode() and stores the
value the function returns into variable
ThisAffiliateCode. Variable ThisAffiliateCode
can now be used to insert the affiliate code
into links and forms.
Line 11 -- Tells the browser that the lines of JavaScript
end here.
Inserting Affiliate Codes Into
a Link
If you insert the affiliate code into your intra-site links, so the affiliate
code is appended to the URL with either a question mark or a hash mark, you'll
be able to send the affiliate code with the visitor, from page to page, without
the use of cookies.
Inserting the affiliate code can be done with JavaScript. This is an overview
of how to do it:
For more information,
[anchor tag link goes here]
Click Here</a>
Not all browsers are JavaScript-enabled. If it's important that default HTML
is inserted even when JavaScript isn't available for a browser, then use
the NOSCRIPT tag to specify the HTML for that contingency.
Here is a working example of JavaScript to insert an affiliate code into
a link. The affiliate code is appended to a hash mark -- the affiliate code
being that which the JavaScript in the HEAD area extracted when the page
was being loaded:
For more information,
<script type="text/javascript" language="JavaScript"><!--
document.write('<a href="http://mydomain.com/page.html#');
document.write(ThisAffiliateCode);
document.write('">');
//--></script>
<noscript>
<a href="http://mydomain.com/page.html">
</noscript>
Click Here</a>
document.write() prints the content
between the parenthesis.
If you're printing a string of characters, enclose the characters between
apostrophes or quotation marks. Whatever you decide to enclose the characters
with, if you use the same character as one of the characters that are to
be printed, precede the character with a backslash. Example:
document.write('He\'s back!');
To print the contents of a variable, put the variable between the parenthesis,
not enclosed with apostrophes or quotation marks.
Inserting Affiliate Codes Into a Form
Any form processed by a script that allows custom fields can have affiliate
codes inserted into form field values. For example, this will take the affiliate
code extracted from the URL and insert it into a hidden filed named
"afc":
<script type="text/javascript" language="JavaScript"><!--
document.write('<input type="hidden" name="afc" value="');
document.write(ThisAffiliateCode);
document.write('">');
//--></script>
<noscript>
<input type="hidden" name="afc" value="something">
</noscript>
That hidden field can be processed
by the form's CGI program just like any other custom hidden field. If the
program can update a database with form field names, like Master Form from
http://willmaster.com/master/form/ can do, then the affiliate code might
be used to measure performance or other statistics.
If you're providing "recommend this site" forms and want your affiliate's
code to be part of the recommended URL, the hidden field representing the
URL being recommended can be modified to append the affiliate code with either
a question mark or a hash mark. Here is an implementation example for use
with Master
Recommend Pro.
<script type="text/javascript" language="JavaScript"><!--
document.write('<input type="hidden" ');
document.write(' name="siteURL" ');
document.write(' value="http://mydomain.com/page.html#');
document.write(ThisAffiliateCode);
document.write('">');
//--></script>
<noscript>
<input type="hidden"
name="siteURL"
value="http://mydomain.com/page.html">
</noscript>
For
Master
Recommend (the free version) replace "siteURL" with "siteurl" in both
places.
If you want to offer a form field where the user can type in the affiliate
code (or sponsor's code, as in the example), yet pre-fill in the code whenever
possible, do something like this:
Your sponsor's code:
<script type="text/javascript" language="JavaScript"><!--
document.write('<input type="text" name="afc" value="');
document.write(ThisAffiliateCode);
document.write('">');
//--></script>
<noscript>
<input type="text" name="afc" value="something">
</noscript>
Redirecting To a Customized
Page
If you have a CGI program that generates customized pages with affiliate
information embedded in it, the following code can redirect the site visitor
to the CGI script. The affiliate code is sent to the script, which allows
the script to customize the page for the visitor.
<script type="text/javascript" language="JavaScript"><!--
var URL = 'http://mydomain.com/cgi-bin/script.cgi?' +
ThisAffiliateCode;
location.href = URL;
//--></script>
Notice that there is no NOSCRIPT
tag here. If the browser is JavaScript-disabled, the page would not be redirected
and everything on the original page would be displayed, whether or not it
is between NOSCRIPT tags.
To load faster in JavaScript-enabled browsers, you might put all of the rest
of the page between NOSCRIPT tags. This would enable the browser to ignore
images and tables and such, and run the JavaScript redirection code sooner.
Will Bontrager
About the Author:
Copyright 2002 Bontrager Connection, LLC
William
Bontrager Programmer/Publisher, "WillMaster Possibilities"
ezine
mailto:possibilities@willmaster.com
Are you looking for top quality scripts? Visit
Willmaster
and check out his highly acclaimed Master Series scripts. Some free, some
for a fee.
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