Trouble creating a custom sort function for a CCK type
Hello,
I'm trying to figure out the best way to use the Views (v1.x) API to create a custom sort function for a CCK type.
Here's what I have:
CCK fields:
- title (string)
- rating_a (int)
- rating_b (int)
- rating_c (int)
- rating_d (int)
I need to develop a way to sort the view by the average of a variable number of the "rating" CCK fields.
For example, if the user wants to sort the nodes only by "rating_a" and "rating_c", then the "order by" clause would look something like this:
...ORDER BY (rating_a + rating_c)/2 DESC
Or, if the user wants to sort the nodes by "rating_b", "rating_c", and "rating_d", the order clause would look like this:
...ORDER BY (rating_b + rating_c + rating_d)/3 DESC
Make sense so far?
The various "rating_*" choices will be coming in via arguments in the form "rating_a+rating_b+rating_c". So far, my plan has been to hook_views_arguments to define the argument, then to write a custom handler. In the custom handler, I'm planning on using $query->add_orderby() in the "filter" $op to actually add the sort criteria.
The problem I'm having is that I'm not sure what to set the add_orderby() parameters to:
add_orderby($table, $field, $order, $alias = '')
When I look at the $query coming into the custom handler, I don't see any of the CCK tables joined. I know that at some point the CCK tables will be there, but it seems that when my module's hooks are called, the CCK stuff hasn't been added yet.
Am I taking the correct approach on this or am I going about this the wrong way? Any help would be appreciated.
Here's a (simplified) copy of the code:
/**
* Implementation of hook_views_arguments.
/
function mymodule_views_arguments() {
$arguments = array(
'ratings' => array(
'name' => t('Ratings'),
'handler' => 'mymodule_views_handler_rating',
'help' => t('This argument sorts the results based on the ratings inputs.'),
),
);
return $arguments;
}
/*
* Implementation of hook_views_handler_arguement.
*/
function mymodule_views_handler_rating($op, &$query, $a1, $a2 = null) {
switch ($op) {
case 'filter':
dsm($query);
//$query->add_orderby($table, $field, $order, $alias = '')
break;
}
}