Trying to get a property of a non-object in 'mymodule_node_access()'

Question

In a custom module, I try to make this code work :

function mymodule_node_access($node, $op, $account) {
  if ($node->type = 'devis' and $op = 'view') {
    $field_language = field_language('node', $node, 'field_project');
    $project_node = node_load($node->fields->field_project[$field_language][0]['value']);
    if ($project_node->uid == $account->uid) {
      return NODE_ACCESS_IGNORE;
    }   
    else {
      return NODE_ACCESS_DENIED;
    }
  } 
}

I get the following notice:

Trying to get a property of a non-object in mymodule_node_access()

I don't know where the problem is.

Answer 1

$node in hook_node_access() can be either a string for the content-type or a node object. I had to test if it was a string or an object.

if (is_string($node)) { 
  return NODE_ACCESS_IGNORE;
}
else {
  // ...
}

Answer 2

Fields are directly on the node object, you're currently trying to find them in another object called fields.

Change this:

$project_node = node_load($node->fields->field_project[$field_language][0]['value']);

To this:

$project_node = node_load($node->field_project[$field_language][0]['value']);

And it should work.