Delay querying store until after subclass computeProperties() methods…

… have run.

Fixes ibm-js#442.

Store.js

@@ -121,19 +121,18 @@ define([
 			return renderItems;
 		},
 
-		/**
-		 * If the store parameters are invalidated, queries the store, creates the render items and calls initItems() 
-		 * when ready. If an error occurs a 'query-error' event will be fired.
-		 * @param props
-		 * @param isAfterCreation
-		 * @protected
-		 */
-		computeProperties: function (props, isAfterCreation) {
-			// If this call is upon widget creation but `this.store` is not available, don't bother querying store
+		computeProperties: dcl.after(function (args) {
+			// Runs after the subclass computeProperties() methods run and possibly set this.query and this.source.
+			// If this call is upon widget creation but `this.source` is not available, don't bother querying store.
+			// If the store parameters are invalidated, queries the store, creates the render items
+			// and calls initItems() when ready.  If an error occurs a 'query-error' event will be fired.
+			// If this call is upon widget creation but `this.store` is not available, don't bother querying store.
+
+			var props = args[0], isAfterCreation = args[1];
 			if (("source" in props || "query" in props) && (this.source || !isAfterCreation)) {
 				this.queryStoreAndInitItems(this.processQueryResult);
 			}
-		},
+		}),
 
 		/**
 		 * Queries the store, creates the render items and calls initItems() when ready. If an error occurs

tests/unit/Store.js

@@ -145,6 +145,49 @@ define([
 			return d;
 		},
 
+		"set query in subclass": function () {
+			// This test confirms that the subclass computeProperties() method can set this.query,
+			// and Store will wait until after that to run the query against the store.
+
+			var MyStoreSubclass = register("my-store-subclass", [HTMLElement, Widget, Store], {
+				idToQuery: "place holder",
+
+				createdCallback: function () {
+					this.storeQueries = [];
+				},
+
+				computeProperties: function (oldVals) {
+					if ("idToQuery" in oldVals) {
+						this.query = {
+							id: this.idToQuery
+						};
+					}
+				},
+
+				queryStoreAndInitItems: dcl.superCall(function (sup) {
+					return function () {
+						this.storeQueries.push(this.query);
+						sup.apply(this, arguments);
+					};
+				})
+			});
+
+			var myStore = new MyStoreSubclass({
+				source: new M({
+					data: [
+						{ id: "foo", name: "Foo" },
+						{ id: "bar", name: "Bar" }
+					],
+					model: null
+				}),
+				idToQuery: "foo"
+			});
+
+			// The new MyStoreSubclass() automatically calls deliver(), so the query has already executed.
+			// Now make sure that it just executed once.
+			assert.deepEqual(myStore.storeQueries, [{ id: "foo" }]);
+		},
+
 		StoreFuncRange: function () {
 			var d = this.async(15000);
 			var store = new C();