[documentation] [Documentation bug] Update needed to node_example.module

[plumbley]

Issue status update for 
http://drupal.org/node/84602
Post a follow up: 
http://drupal.org/project/comments/add/84602

 Project:      Documentation
 Version:      <none>
 Component:    Developer Guide
 Category:     bug reports
 Priority:     normal
 Assigned to:  Anonymous
 Reported by:  plumbley
 Updated by:   plumbley
-Status:       active
+Status:       patch (code needs review)
 Attachment:   http://drupal.org/files/issues/node_example.module.patch (2.44 KB)

OK, the attached patch corrects node_example.module for 4.7. I have not
tested with HEAD, but I believe it should work with that too.


Main fix is to separate out the change to $node that was in
hook_validate() into a new hook_submit(), as indicated above. I've
tested this works with 4.7, but I don't have a working HEAD yet (as it
were).


As a bonus, this patch also includes "E_ALL Compliance" fixes to remove
PHP Notices. Many modules produce these on "create" forms by failing to
check whether the default value is set yet, so it would be nice for
node_example.module to do this as now recommended too.


Best wishes,


Mark.




plumbley



Previous comments:
------------------------------------------------------------------------

Sun, 17 Sep 2006 08:06:24 +0000 : plumbley

Current CVS documentation for hook_example_validate() includes the
example
<?php
function node_example_validate(&$node) {
  [ ... if ($node->quantity) { ]
    // Let an empty field mean "zero."
    $node->quantity = 0;
  }
} 
?>
But since 4.7 it looks like any changes to $node made in hook_validate
are ignored. E.g. in modules/node/node.module we have
<?php
function node_validate($node, $form = array()) {
  ...
  node_invoke($node, 'validate', $form);
  node_invoke_nodeapi($node, 'validate', $form);
}
?>
which is pass-by-value rather than pass-by-reference. So although
node_invoke() passes by reference, no changes to $node can "escape" out
of node_validate.


I'm guessing this is by design, but if so the documentation should say
what to do instead. E.g. I *think* form_set_value() should now be used,
but its a bit non-obvious. For example, I used something similar to the
following elsewhere (in 4.7):
<?php
  form_set_value(array('#parents' => array('quantity')), 0);
?>
Is this now the recommended route to change nodes? (or not?). Mark.


PS Looks like the change to validation operation in 4.7 also caused
problems for node_import, which ideally should be able to validate a
node without requiring a form to be present, so a documentation update
might help getting validation working there too.




------------------------------------------------------------------------

Sun, 17 Sep 2006 19:13:44 +0000 : plumbley

Renamed now I finally found out what I probably should have found much
earlier about the 4.7 submit process (see e.g.
http://drupal.org/node/22218#node_hook_order). Please ignore my previous
rubbish about form_set_value().


It looks like node_example.module as appears in 4.7 at
http://api.drupal.org/api/4.7/file/developer/examples/node_example.modul...
and CVS at
http://api.drupal.org/api/HEAD/file/developer/examples/node_example.modu...
actually applies to 4.6, and is in need of update.


I'm still a bit new here but perhaps hook_validate() should now be
pass-by-value and read e.g.:
<?php
function node_example_validate($node) {
  // If the field is set, it must be a number
  if (!empty($node->quantity) && !is_numeric($node->quantity)) {
    form_set_error('quantity', t('The quantity must be a number.'));
  }
}
?>
with a new hook_submit() which performs the modification
<?php
function node_example_submit(&$node) {
  if (empty($node->quantity)) {
    // Let an empty field mean "zero."
    $node->quantity = 0;
  }
}
?>
If its too fiddly to fix for the moment, perhaps just a note to say
"node_example.module applies to 4.6, see
http://api.drupal.org/api/4.7/file/developer/hooks/node.php for up to
date documentation" in the meantime? Mark.




------------------------------------------------------------------------

Sun, 17 Sep 2006 20:41:18 +0000 : pwolanin

I think form_set_value *is* needed to chage a vlue at the validate sage,
as opposed to being able to directly change the node in 4.6.  I was just
try to help someone figure this out recently:
http://drupal.org/node/83130