Creating a relation programmatically

er.. what errors?

Can you please post a sample of your error messages, and steps to reproduce?

If you think this isn't a bug with relation, but with entity.module, please move it there.

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This seems to work if you want to add a relation field to your entity/content type:

$field = array(
      'field_name' => 'department_firm_reference',
      'cardinality' => 1,
      'type'        => 'relation',
);
field_create_field($field);
$instance = array(
  'field_name' => 'department_firm_reference',
  'label' => 'Firm',
  'widget' => array(
    'type' => 'relation_default',
  ),
),
$instance['entity_type'] = 'node';
$instance['bundle'] = 'department';
field_create_instance($instance);

But I don't think that's what you're trying to achieve...

Try this:

$node_id_left = 1;
$entity_type_right = 'node';
$entity_id_right = 2;
$relation_field = 'relation_field_name_here';

$node = node_load($node_id_left);
$node->{$relation_field}[LANGUAGE_NONE][] = array(
  'other_entity_type' => $entity_type_right,
  'other_entity_id' => $entity_id_right,
);
node_save($node);

Fixed in reboot branch.

$predicate = 'likes';
$entity_keys = array(
  array('user', 6),
  array('node', 4),
);
relation_create($predicate, $entity_keys);

Will create a relation between user 6 and node 4, of the type 'likes'. At the moment, you need to pre-create the relation type ($predicate) in admin/structure/relation.

On the same topic, I'm trying to write the code to create relations from Rules.
I'm looking in the code for this "relation_create" function, but I can't seem to find it.

Which function would I direct Rules to call when creating a new Relation?

If I look at the right branch, it's so much easier to find the function.

Reopening, again, because this seems to have changed significantly recently.

A little, now you pass a list of associative arrays to relation_create, each having an entity_type and an entity_id.

The code in post #10 doesn't actually save the relation, you have to call relation_save with the return value from relation_create. relation_insert is coded to do both with one call.

However, I'm having issues with relations not getting created at all. I see versions in the relation and relation_revision tables, but nothing in field_data_endpoints or field_revision_endpoints.

        $relmap = array();  // to save the relations
 
//node creation happens here.  works fine.  nodes are saved to system without incident.
       //$order_id = nid of an insertion_order node 
       //$preprint_nid = nid of a preprint_insert node

//in this use case, I have multiple order nodes being related to a single preprint insert node.

        $relmap[]=array(
                array('insertion_order',$order_nid),
                 array('preprint_insert',$preprint_nid)
                        );
 
        //relate the insertion order nodes to one preprint insert node
        $predicate = 'belongs to';  //already created as relation type
        //create the relations to the preprint insert node
        foreach($relmap as $relation){
                relation_insert($predicate,$relation);
        }

Ideas? I don't get any errors. However, when I try to put together a view showing the data, there's no related orders on the common preprint insert node. There's also nothing listed at admin/content/relation

insertion_order is a bundle (node type) and so is preprint_insert. You wanted entity types and not bundles in there. array('node', $nid)

The reason the code in #10 is wrong is that it's 9 months old. A LOT has changed since then. But that code will still work if you replace _create with _insert.

You don't need that foreach. You need to put your $relmap in directly as the endpoint. See the doxygen for relation_create(). http://drupalcode.org/project/relation.git/blob/refs/heads/7.x-1.x:/rela...

Looks like relation_insert() needs to return relation_save, not just run it. Also, doxygen needs to be updated for those api functions.

Okay, here is updated code #10 and #17 examples combined.

$endpoints = array(
  array('entity_type' => 'node', 'entity_id' => $order_nid),
  array('entity_type' => 'node', 'entity_id' => $preprint_nid)
);
$rid = relation_insert('belongs to', $endpoints);

Thanks @chx, @naught101 and @mikran. I appreciate all your help. However, I gave everyone's suggestions a try with no success thus far.

@naught101, there's a snippet of code I failed include in my example with regards to $relmap. It contains a list of all the relations I'm going to create. I may have 1+ insertion_order nodes that must be related to a single preprint_insert node. Hence the array/list. Thanks for catching that however.

@mikran, relation_insert does not return anything. I just broke my code up into the constituent relation_create and relation_save calls to get a $rid.

I'm using:

D7.10
Relation 7.x-1.x-dev (indicated as 7.x-1.0-beta3+39-dev in the Modules screen)

Chunk of example code:

//@chx's suggested relation array contents, tried this way first	    
		$endpoints=array(
			array('node', $order_nid),
			array('node', $preprint_nid)
		);
//@mikran's suggested relation array contents, tried this way second.
		$endpoints = array(
  			array('entity_type' => 'node', 'entity_id' => $order_nid),
  			array('entity_type' => 'node', 'entity_id' => $preprint_nid)
		);
		
		//creating the relation and saving it.		
		$relation = relation_create('belongs to',$endpoints);
		$rid = relation_save($relation);
		

No errors are thrown using this code with either suggested array configuration.

I notice no relations are created as no corresponding entries exist in the field_data_endpoints table. $rid does contain a return value that corresponds to an entry in the relation table. relation_revision is also updated, but on my system all the rid fields are 0.

If I use the Relation module's entity collector block, I can create a relation, successfully. Entries appear in the field_data_endpoints table properly. relation_revision is similarly updated, but all the rid fields are still 0.

Is there something else I am doing incorrectly here?

relation_insert is fixed, and now returns the $rid

have you tried relation_load($rid) after creating the above relations? what does that return?

@naught101, I added code to immediate load the relation after I saved it as you suggested. Called dpm() on the relation, and it shows the proper data.

Not sure what changed as I walked away from this for some time today, but things seem to be working as of right now.

Turned off the relation_load() and dpm() and things seem to still be working.

@naught101, thanks for the assistance. I'm officially shaking my head!

Okay, I think I figured out why my relations weren't being created.

The predicate name passed to relation_create must be a machine name version, not the plain text version.

In my case, my relation bundle type was called 'belongs to'. The relations would not be created properly unless I used 'belongs_to' as the predicate name.

Right, I should have noticed that from the space in bundle type name but I'm glad you figured it out eventually.

how to update relation fields programatically?

That is same as any entity basically.

$relation->field_name[LANGUAGE_NONE][0]['value'] = 'new_value';
relation_save($relation);

Please create new issues in the future.

I want to create relation with relation module by using custom module .. how i create custom module please help me,