How can I send an email using the Rules module to a user specified via Entity Reference in a Content Type?

Question

This question is similar to others posed, but all the answers I can find appear to refer to Drupal 6, with CCK fields.

I am using Drupal 7 with the Rules module enabled.

I have created a custom Content Type and one of the fields is an Entity Reference, which allows a registered user to be selected as the Content Type is added. Essentially an administrator can associate a registered website user with the content item being added.

I need to email the referenced user when another field value within the Content Type is changed. I'm sure this is possible via the Rules module, but I cannot get the mail to send.

It must be a fairly common situation, emailing a referenced user when a field value is updated, but I have looked at the online notes for the Rules module and cannot find an example of this particular use case.

Has anybody managed to achieve the same outcome as I am seeking?

Thank you.

Answer 1

After some trial and error, I found how to reference the field.

Within the Conditions section of the rule, I needed to:

• Add "entity has field"
• Enter "node" within the Data Selector box
• Select the entity reference field within the Value dropdown

I was then able to refer to the field required, with the mail parameter appended, directly from a standard Send Mail action (i.e. [node:MY-REFERENCED-FIELD:mail]).

Answer 2

I would do a custom module to add a function to run in the "To" value field of your rule. Try:

<?php

function my_module_user_lookup($nodeid) {
    $node = node_load($nodeid);
    $userid = $node->YOUR_FIELD_NAME_HERE['und'][0]['target_id'];
    $user = user_load($userid);

    return $user->mail; 
}
?>

Then in your rule add this php function (make sure to run it as PHP to your To field. I believe <?php my_module_user_lookup($node->id); ?> should do it. From there you just need to add the logic for sending when the node is updated, but that is all apart of rules.