template_preprocess_html(&$vars) dynamic code I have an html template variable called "sitepage" that needs to be set by a module based on node relationships.

Is there a way to set html.tpl variables from a module?  

function dc_preprocess_html(&amp;$vars)
{
    $vars['sitepage'] = '/*Insert Business Logic as described below*/';
}


The logic for what the sitepage should be is as followed:


If we are on a car model or car make page then find the car make node and check to see if there is a node reference to an Advertiser node. 
Using the advertiser node, check the field "field_sponsor_site_page" to determine the site page


I can easily do this in the module code, but need to do this so I can put the variable in html.tpl.php

The way it works now:

I have 2 pages in play:


Car Detail Page: model/[Car Make Node FIELD_COLLECTION_ID]
List Cars of a particular model: makes/[Car Make Node Id]


A car make node has a node reference to Advertiser. The advertiser has a sitepage that needs to be inserted into html.tpl.php in both cases based on this business logic
try 

hook_module_implements_alter()


to alter the hooks order