CRM-21849: Switch loading relationship data from backend to frontend

The formatting of relationship data is a FE related task and can be done
 in Javascript. This also allows reloading the data if some options
 change after editing relationship types.

CRM/Contact/Form/Relationship.php

@@ -299,9 +299,6 @@ public function buildQuickForm() {
     // Select list
     $relationshipList = CRM_Contact_BAO_Relationship::getContactRelationshipType($this->_contactId, $this->_rtype, $this->_relationshipId);
 
-    // Metadata needed on clientside
-    $this->assign('relationshipData', self::getRelationshipTypeMetadata($relationshipList));
-
     foreach ($this->_allRelationshipNames as $id => $vals) {
       if ($vals['name_a_b'] === 'Employee of') {
         $this->assign('employmentRelationship', $id);

templates/CRM/Contact/Form/Relationship.tpl

@@ -144,8 +144,97 @@
       CRM.$(function($) {
         var
           $form = $("form.{/literal}{$form.formClass}{literal}"),
-          relationshipData = {/literal}{$relationshipData|@json_encode}{literal};
-        $('[name=relationship_type_id]', $form).change(function() {
+          $relationshipTypeSelect = $('[name=relationship_type_id]', $form),
+          relationshipData = {},
+          contactTypes = {};
+
+        $('body').on('crmOptionsEdited', 'a.crm-option-edit-link', refreshRelationshipData);
+
+        // Initial load and trigger change on select
+        refreshRelationshipData().done(function() {
+          $relationshipTypeSelect.change();
+        });
+
+        /**
+         * Fetch contact types and reset relationship data
+         */
+        function refreshRelationshipData() {
+          var defer = $.Deferred();
+
+          getContactTypes().then(function() {
+            resetRelationshipData().then(function() {
+              defer.resolve();
+            });
+          });
+
+          return defer.promise();
+        }
+
+        /**
+         * Refreshes the relationship data using latest relationship types
+         */
+        function resetRelationshipData() {
+          var subtype,
+            type,
+            label,
+            placeholder,
+            defer = $.Deferred();
+
+          relationshipData = {};
+
+          CRM.api3("RelationshipType", "get").done(function (data) {
+            $.each(data.values, function (key, relType) {
+              $.each(["a", "b"], function (index, suffix) {
+                subtype = relType["contact_subtype_" + suffix];
+                type = subtype || relType["contact_type_" + suffix];
+                label = getContactTypeLabel(type) || "Contact";
+                placeholder = "- select " + label.toLowerCase() + " -";
+                relType["placeholder_" + suffix] = placeholder;
+              });
+              relationshipData[relType["id"]] = relType;
+            });
+
+            defer.resolve(relationshipData);
+          });
+
+          return defer.promise();
+        }
+
+        /**
+         * Gets a contact type label based on a provided name
+         * @param {String} name - the name of the contact type
+         */
+        function getContactTypeLabel(name) {
+          var label = "";
+
+          $.each(contactTypes, function(index, contactType) {
+            if (contactType.name === name) {
+              label = contactType.label;
+              return false;
+            }
+          });
+
+          return label;
+        }
+
+        /**
+         * Fetches contact types
+         */
+        function getContactTypes() {
+          var defer = $.Deferred();
+          if ($.isEmptyObject(contactTypes)) {
+            CRM.api3("ContactType", "get").done(function (data) {
+              contactTypes = data.values;
+              defer.resolve(contactTypes);
+            });
+          } else {
+            defer.resolve(contactTypes);
+          }
+
+          return defer.promise();
+        }
+
+        $relationshipTypeSelect.change(function() {
           var
             val = $(this).val(),
             $contactField = $('#related_contact_id[type=text]', $form);
@@ -190,7 +279,7 @@
 
             CRM.buildCustomData('Relationship', rType);
           }
-        }).change();
+        });
       });
       {/literal}
     </script>