External ads in Drupal

Allrighty. So someone is twisting your arm and trying to make you add blocks of ad network script tags on your perfect Drupal site? Polluting your DOM? No way, not on my shift! Here's how to keep it safe.

First you need a basic understanding of a few concepts. I'll use Taxonomy, CCK, Views and some funky template preprocess magic all bound together by our beloved page.tpl.php. The external ads are presumably a bunch of script tags.

Start out by creating a .php or .html file that hold each ad, place these somewhere within your drupal folder in a folder, why not name it "ads". Any cache-busting techniques should be done with php. Note the full URL:s.

Now for some Drupal hands-on: Create a Vocabulary that will hold the tags that will tell Drupal which nodes get what ads. Name it "Customers". It should be a flat vocabulary.

Next, create a content-type that will serve as the holder for the dreaded external ads. Name it "Customer". Add as many text fields as the total of your ad slots. The text fields will only hold URLs and should be plain text only. Save when done. (You can easily add more custom fields here that can be used for your nodes)

Move on to Taxonomy->Vocabularies. Configure the previously added vocab so that it is selected for your "regular" content-type so you can relate it with its Customer. Now, add as many terms to the vocabulary as you have customer sections, i.e. companya, companyb, companyc.

Create a Customer node. Populate the fields with the URL:s from the first step. Fill the title field with one of your terms from Customers, for example "companya". Note: This needs to be unique.

Now, edit one of your "regular" nodes. Add the term "companya" to the node and save it.

Set up a view to load your Customer data by creating a new View, naming it "customerdata". The View should be Unformatted and row style should be Node. Add Node:Title as an argument, accepting the default 404/hide view settings. Add a filter on node type and set it to Customer. Save it.

The time has come for us to bring it all together and display the ads. This is when your template.php hacking skills come into play. Fire up an editor and open template.php for the theme you'll be using. You now need to create a function that will load the data from the Customer node and attach it to the node before rendering.
You also need to make sure this gets called when the page is constructed. You might need it on the page level or the node level, it depends.

template.php:


The last part is your page.tpl.php. To print your now safer external ads, construct something along the lines of

echo "iframe src=" . $ad1 . "/iframe";

The same can be repeated for any custom field. The process is the same, add it to the Customer content-type, fill out the Customer node, tag your node(s) with the appropriate term and output it in your page.tpl.php.

Upload template.php and page.tpl.php, flush your caches and load one of your tagged nodes. You should now see the ad being displayed. If not, check the html source for your iframe tag or flush your cache.

This example is just a basic example and can be improved upon endlessly. A few of those being Rules integration, error checking and Views caching.