add additional example

scripts/tutorials/entity_edit_filters/prevent-add-delete-or-edit-of-entities-with-name-of-zone.js

@@ -0,0 +1,40 @@
+//
+// prevent-add-delete-or-edit-of-entities-with-name-of-zone.js
+// 
+//
+// Created by Brad Hefta-Gaub to use Entities on Feb. 14, 2018
+// Copyright 2018 High Fidelity, Inc.
+//
+// This sample entity edit filter script will get all edits, adds, physcis, and deletes, but will only block
+// deletes, and will pass through all others.
+//
+// Distributed under the Apache License, Version 2.0.
+// See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+function filter(properties, type, originalProperties, zoneProperties) {
+
+    // for adds, check the new properties, if the name is the same as the zone, prevent the add
+    // note: this case tests the example where originalProperties will be unknown, since as an
+    // add message, there is no existing entity to get proprties from. But we need to make sure
+    // zoneProperties is still set in the correct 4th parameter.
+    if (type == Entities.ADD_FILTER_TYPE) {
+        if (properties.name == zoneProperties.name) {
+            return false;
+        }
+    } else {
+        // for edits or deletes, check the "original" property for the entity against the zone's name
+        if (originalProperties.name == zoneProperties.name) {
+            return false;
+        }
+    }
+    return properties;
+}
+
+filter.wantsToFilterAdd = true;  // do run on add
+filter.wantsToFilterEdit = true;  // do not run on edit
+filter.wantsToFilterPhysics = false;  // do not run on physics
+filter.wantsToFilterDelete = true;  // do not run on delete
+filter.wantsOriginalProperties = "name";
+filter.wantsZoneProperties = "name";
+filter;