Trigger on selected field change

Question

So I have a Drupal 7 Workflow rule where an email is sent out when a select field on a comment is set to "Approved'.

This works fine with the exception being if I then add an additional comment to the form, the email is then re-sent. the reason being is that I'm just checking the select field value and triggering the email based on the value.

I just want the email to be sent when the select field is initially set to "Approved".

Here is the export of the rule in question:

{ "rules_notify_status_approved_test" : {
"LABEL" : "Notify - Status Approved TEST",
"PLUGIN" : "reaction rule",
"OWNER" : "rules",
"REQUIRES" : [ "rules" ],
"ON" : { "node_update--request_ad_match" : { "bundle" : "request_ad_match" }     },
"IF" : [
  { "node_is_of_type" : {
      "node" : [ "node" ],
      "type" : { "value" : { "request_ad_match" : "request_ad_match" } }
    }
  },
  { "user_has_role" : {
      "account" : [ "site:current-user" ],
      "roles" : { "value" : { "4" : "4" } }
    }
  },
  { "data_is" : { "data" : [ "node:field-request-status" ], "value" : "74" }     },
  { "AND" : [] }
],
"DO" : [
  { "variable_add" : {
      "USING" : { "type" : "user", "value" : [ "node:author" ] },
      "PROVIDE" : { "variable_added" : { "node_author" : "node author" } }
    }
  },
  { "mail" : {
      "to" : "email@email.com",
      "subject" : "request has been approved",
      "message" : "request has been approved",
      "language" : [ "" ]
    }
  }
]
}
}

Any direction is appreciated.

Thanks!

Answer 1

It seems that to get it to work, you should at least add yet another Rules Conditions, in which you compare the value of your field-request-status field, for both the original value (before editing the field) and the (new) updated value, to verify if they are different.

For a variation of your question, with way more details on this, refer to the accepted answer (disclosure: it's mine ...) to "How to send an email using Rules when a node's boolean field is changed?".