how to force drupal function to not use DB cache?

Question

i have a module and i am using node_load(array('nid' => arg(1))); now the problem is that this function keep getting its data for node_load from DB cache.
how can i force this function to not use DB cache?
Example
my link is http://mydomain.com/node/344983
now:
$node=node_load(array('nid'=>arg(1)),null,true);
echo $node->nid . " -- " arg(1);
output
435632 -- 435632
which is a randomly node id (available on the system)
and everytime i ctrl+F5 my browser i get new nid!!

Thanks for your help

function custom_node_menu(){ $items = array(); $items['node'] = array ( 'title' => 'node', 'page callback' => 'drupal_not_found', 'access callback' => TRUE, 'type' => MENU_CALLBACK, ); return $items; } — Alaa
Does node_load(arg(1)) show similar issues? What does print arg(1) output? Is it possible you've got caching on for anonymous users and you're just seeing an earlier output from the page? — ceejayoz
it is written above (435632),,, the problem is that arg(1) getting incorrect value... node_load doesn't have any problem when you use $reset=true but the problem is with arg api itself!!! i dont know why it gets incorrect values!! — Alaa
I very much doubt the issue is with arg() itself, or Drupal would cease to function entirely. See my edit regarding caching - try clearing the cache with devel.module. — ceejayoz

anschauung anschauung · Accepted Answer · 2010-12-29T19:49:09

Where are you calling this? For example, are you using it as part of your template.php file, as part of a page, or as an external module?

Unless you have this wrapped in a function with its own namespace, try naming the variable differently than $node -- for example, name it $my_node. Depending on the context, the 'node' name is very likely to be accessed and modified by Drupal core and other modules.

If this is happening inside of a function, try the following and let me know what the output is:

$test_node_1 = node_load(344983); // Any hard-coded $nid that actually exists
echo $test_node_1->nid;

$test_node_2 = node_load(arg(1)); // Consider using hook_menu loaders instead of arg() in the future, but that's another discussion
echo $test_node_2->nid;

$test_node_3 = menu_get_object(); // Another method that is better than arg()
echo $test_node_3->nid;

Edit:

Since you're using hook_block, I think I see your problem -- the block itself is being cached, not the node.

Try setting BLOCK_NO_CACHE or BLOCK_CACHE_PER_PAGE in hook_block, per the documentation at http://api.drupal.org/api/drupal/developer--hooks--core.php/function/hook_block/6

You should also try to avoid arg() whenever possible -- it's a little bit of a security risk, and there are better ways to accomplish just about anything arg() would do in a module environment.

Edit:*

Some sample code that shows what I'm referring to:

function foo_block ($op = 'list', $delta = 0, $edit = array()) {
    switch ($op) {
      case 'list':
        $blocks[0] = array(
          'info' => 'I am a block!',
          'status' => 1,
          'cache' => BLOCK_NO_CACHE // Add this line
        );
        return $block;
      case 'view':
       .....
    }
}

how to force drupal function to not use DB cache?

4 Answers