[development] hook_nodeapi()

[Fernando Silva]

I do not quite understand that. Let's assume the "example.module" that
creates a new node type.

I'll must use the "example_load()" hook to load some data from an extra table:
function example_load($node) {
  $additions = db_fetch_object(db_query('SELECT * FROM {mytable} WHERE
nid = %s', $node->nid));
  return $additions;
}

But then, if I use "example_nodeapi()" instead the code should be
something like this:
function example_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  switch ($op) {

    case 'load':

      $additions = db_fetch_object(db_query('SELECT * FROM {mytable}
WHERE nid = %s', $node->nid));
      return $additions;
  }
}

It's the exact same code, but we also need to have sure that both API
functions run at exactly the places. If we go to the node.module, in
the node_load() function we have at the lines 525 and 531 we have
*exactly* the same code to invoke both APIs.

This means, that when the nodeapi() is invoked with other $op it is
already loaded. Or else, you can be saying that if another module (eg.
"intercept.module") wants to intercept the 'load', the node will not
be 'loaded':
* example.module implements a new node type
* node_load() will load example.module new node type by doing hook_load()
* intercept.module will do something to the example.module node by
using nodeapi()

Is this a correct conclusion, or I am missing something?

This seems to me a bit strange, because in this case the only reason
we have hook_load() and hook_nodeapi('load') is because we can't get a
way to enforce the correct 'loading' order with hook_nodeapi.

Or can we?! If with the new "install system" we have module
dependencies, why can't we have a way to give priorities to those
dependencies...

As a side note, this behaviour is implemented since Drupal 4.6

Thanks,
  Fernando Silva


On 1/3/07, Gerhard Killesreiter <gerhard at killesreiter.de> wrote:
> Fernando Silva wrote:
> > node_load()
> > if ($extra = node_invoke($node, 'load')) {
> > foreach ($extra as $key => $value) {$node->$key = $value;}}
> > if ($extra = node_invoke_nodeapi($node, 'load')) {
> > foreach ($extra as $key => $value) {$node->$key = $value;}}
> >
> > node_save()
> > node_invoke($node, 'insert');
> > node_invoke_nodeapi($node, 'insert');
> > node_invoke($node, 'update');
> > node_invoke_nodeapi($node, 'update');
> >
> > node_delete()
> > node_invoke($node, 'delete');
> > node_invoke_nodeapi($node, 'delete');
> >
> > The conclusion is that the "nodeapi" is the way to do things, and that
> > the other way was just keeped as unnecessary compatibility, and should
> > be quickly deprecated.
>
> I don't think that this is a valid conclusion. /If/ you create your own
> node type and it has an extra table you should use the basic hooks.
> Because then your node will already be fully populated once it gets into
> nodeapi and other modules can act on the full node.
>
> Cheers,
>         Gerhard
>