Changing wp_title from inside my Wordpress Plugin - php

Question

nearly finished my wp plugin for an estate agent,
I spidered the site for 404's etc, i noticed that my property details pages were spider'd in which all 45 page titles were : ( details | sitename ) (page titles are shown dynamicly from an ID being passed via querystring)
now I've got my nice urls fixed, urls look like this...
wpsite.com/details/20043/property+for+sale+in+this+area
In Which...
propid = 20043
propname = property+for+sale+in+this+area
both of these are querystring values which are used to re-write the urls.
'query_vars' => array('propid', 'propname'),
'rules' =>
array( '(.+?)/([^/]+)/([^/]+)/?$' => 'index.php?pagename=$matches[1]&propid=$matches[2]&propname=$matches[3]' )
);
Now when the property details page is loaded im trying to hook into the wordpress filter
wp_title but this isnt working the way i expected..
this is the code im using to generate the titles
function wp_myplugin_property_title()
{
$wp_acquaint_id = get_option("wp_system_id");
$propid = get_query_var('propid');
if(isset($propid)){
$seotitle = wp_myplugin_seo_title($propid);
}else{
$seotitle = "TEST Title";
}
return $seotitle;
}
if( is_page('details') ){
add_filter('wp_title', wp_myplugin_property_title, 100);
}
the function used within that function: wp_myplugin_seo_title($propid) generates the actual title i want to use...
function wp_myplugin_seo_title($propid)
{
$wp_acquaint_id = get_option("wp_acquaint_id");
$xml = wp_myplugin_get_property($propid);
foreach($xml->PropertiesDataSet->Properties as $node) {
include('xml_loop.php');
if($bedrooms==0){ }else{ $seo_title.= $bedrooms." bedroom "; }
$seo_title.= wp_myplugin_get_property_type($type_id)." "; //ie:flat
$seo_title.= str_replace("(","",$street);
$seo_title.= " ".$town." | ".get_bloginfo('name');
}
return $seo_title;
}
Im finding that with the if(is_page()) in place around the filter the page title dosnt change and if i remove the is_page, the prop details page title works fine but!!!
while on the property listing page the page title is looping through all the properties on that page and producing a page title around 1000 char long..!
I have been hunting around for a better way to deal with this but any help would be great..
Cheers
Marty
ps: currently running wordpress seo by Yoast!
thats why ive set the priority as 100 in the add_filter just to see if it would overwrite the title..

Answer 1

Using is_page in functions.php doesn't work, as it runs before wp knows what page it's going to render, or even if it's a page to begin with. Stick the is_page() inside the function, and it should work. Like:
function wp_myplugin_property_title()
{
if( is_page('details') ){
$wp_acquaint_id = get_option("wp_system_id");
$propid = get_query_var('propid');
if(isset($propid)){
$seotitle = wp_myplugin_seo_title($propid);
}else{
$seotitle = "TEST Title";
}
return $seotitle;
}
}
add_filter('wp_title', wp_myplugin_property_title, 100);