[CORD-1927] Fixing generate url for service models

Change-Id: I08d0d853ba2ab041626e133d079ab4562d73171e
(cherry picked from commit 6349847ecd1040111de5e7def26304e9e093cb92)
diff --git a/src/app/datasources/helpers/modeldefs.service.ts b/src/app/datasources/helpers/modeldefs.service.ts
new file mode 100644
index 0000000..152b5e8
--- /dev/null
+++ b/src/app/datasources/helpers/modeldefs.service.ts
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as _ from 'lodash';
+import * as pluralize from 'pluralize';
+import {IXosModel} from './model-discoverer.service';
+
+export interface IXosModeldefsCache {
+  cache(modelDef: IXosModel): void;
+  get(modelName: string): IXosModel;
+  getApiUrlFromModel(model: IXosModel): string;
+  serviceNameFromAppName(appName: string): string;
+}
+
+export class XosModeldefsCache implements IXosModeldefsCache {
+
+  private xosModelDefs: IXosModel[] = [];
+
+  public cache(modelDef: IXosModel): void {
+    if (!_.find(this.xosModelDefs, m => m.name === modelDef.name)) {
+      this.xosModelDefs.push(modelDef);
+    }
+  }
+
+  public get(modelName: string): IXosModel|null {
+    return _.find(this.xosModelDefs, m => m.name === modelName);
+  }
+
+  public serviceNameFromAppName(appName: string): string {
+    return appName.replace('services.', '');
+  }
+
+  public getApiUrlFromModel(model: IXosModel): string {
+    // FIXME move pluralize from config to a separate service
+    if (model.app === 'core') {
+      return `/core/${pluralize(model.name.toLowerCase())}`;
+    }
+    else {
+      const serviceName = this.serviceNameFromAppName(model.app);
+      return `/${serviceName}/${pluralize(model.name.toLowerCase())}`;
+    }
+  }
+}