3

I'm getting no love from hook_query_alter. I have a simple query to which I want to add a tag, while also adding a node_access tag. Thus the whole query looks like this:

$the_nodes = db_select('node', 'n')
     ->condition('n.type', 'some_node_type')
     ->fields('n', array('nid', 'title'))
     ->addTag('node_access')
     ->addTag('my_custom_tag')
     ->execute()->fetchAll();

I then define a handler in one of my modules and litter it with debugging statements, hoping something will happen:

function mymodule_query_alter(QueryAlterableInterface $the_query) {
    dsm("inside mymodule_query_alter");
    dsm($the_query);
    if ($the_query->hasTag('my_custom_tag')) {
        dsm('Found it!');
        // do real work here
    }
}

I then clear the system cache. Once I've done this, the following things happen:

  • My handler is running, and reports a number of invocations from various system calls.
  • The objects being dumped by the dsm calls are all very much alike -- they contain only an alterTags array, which typically has entries for either node_load_multiple or file_load_multiple, but nothing else -- certainly nothing like a full Query object.
  • None of the alterTags arrays have an entry for my_custom_tag.
  • The inner "Found it!" message never fires.

Arggh. This is my first encounter with hook_query_alter(), and I'm probably just missing something basic about its use. Can anybody clue me in? (BTW, based on some browsing around, I've also tried defining handlers for my_module_query_my_custom_tag_alter and my_module_query_node_access_alter, but never see anything from them.)

  • Your implementation of hook_query_alter seem correct for me. Are you sure you query is executed? – gagarine Mar 19 '13 at 23:22
  • Well, there's progress. I now have my_module_query_alter() finding my_custom_tag. If I do dsm($the_query), all I see is the alterTags array. But I'm apparently getting the query object, because I can dump (string)$theQuery and see the sql version of the query, and I can do $the_query->orderBy('n.title'), and the ordering will happen. So, yay, I guess. But shouldn't there be some way for me to see the query object itself, so I can figure out how to make the changes in the query that are the whole point of being here? – Jim Miller Mar 20 '13 at 0:01
0

Just to close this item out: It appears that my definition of hook_query_alter was, in fact, working correctly. My problem was in assuming that I would be able to do things like dsm($the_query) and see the components of the query object in preparation for doing stuff with them. This doesn't seem to be the case -- dsm() wasn't returning anything of real use other than alterTags, but the orderby() (and other similar actions) did in fact alter the query. So, I'd argue that it's a bit confusing, but works-as-designed, I guess...

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