MOBILE-2261 core: Implement Logger service

README.md

@@ -1,7 +1,7 @@
-Moodle Mobile 2.x
+Moodle Mobile
 =================
 
-This is the primary repository of source code for the official Moodle Mobile app version 2.x.
+This is the primary repository of source code for the official Moodle Mobile app.
 
 * [User documentation](http://docs.moodle.org/en/Moodle_Mobile)
 * [Developer documentation](http://docs.moodle.org/dev/Moodle_Mobile)

package-lock.json

@@ -2752,6 +2752,11 @@
         }
       }
     },
+    "moment": {
+      "version": "2.19.1",
+      "resolved": "https://registry.npmjs.org/moment/-/moment-2.19.1.tgz",
+      "integrity": "sha1-VtoaLRy/AdOLfhr8McELz6GSkWc="
+    },
     "ms": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",

package.json

@@ -38,13 +38,14 @@
     "@ionic-native/sqlite": "^4.3.2",
     "@ionic-native/status-bar": "4.3.0",
     "@ionic/storage": "2.0.1",
+    "electron-builder-squirrel-windows": "^19.3.0",
+    "electron-windows-notifications": "^1.1.13",
     "ionic-angular": "3.7.1",
     "ionicons": "3.0.0",
+    "moment": "^2.19.1",
     "rxjs": "5.4.3",
     "sw-toolbox": "3.6.0",
-    "zone.js": "0.8.18",
-    "electron-windows-notifications": "^1.1.13",
-    "electron-builder-squirrel-windows": "^19.3.0"
+    "zone.js": "0.8.18"
   },
   "devDependencies": {
     "@ionic/app-scripts": "3.0.0",

src/app/app.module.ts

@@ -5,6 +5,7 @@ import { SplashScreen } from '@ionic-native/splash-screen';
 import { StatusBar } from '@ionic-native/status-bar';
 
 import { MyApp } from './app.component';
+import { CoreLoggerProvider } from '../providers/logger';
 
 @NgModule({
   declarations: [
@@ -21,7 +22,8 @@ import { MyApp } from './app.component';
   providers: [
     StatusBar,
     SplashScreen,
-    {provide: ErrorHandler, useClass: IonicErrorHandler}
+    {provide: ErrorHandler, useClass: IonicErrorHandler},
+    CoreLoggerProvider
   ]
 })
 export class AppModule {}

src/providers/logger.ts

@@ -0,0 +1,72 @@
+// (C) Copyright 2015 Martin Dougiamas
+//
+// 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 { Injectable } from '@angular/core';
+import * as moment from 'moment';
+
+/**
+ * Helper service to display messages in the console.
+ *
+ * @description
+ * This service is meant to improve log messages, adding a timestamp and a name to all log messages.
+ *
+ * In your class constructor, call getInstance to configure your class name:
+ * this.logger = logger.getInstance('InitPage');
+ *
+ * Then you can call the log function you want to use in this logger instance.
+ */
+@Injectable()
+export class CoreLoggerProvider {
+    /** Whether the logging is enabled. */
+    public enabled: boolean = true;
+
+    constructor() {}
+
+    /**
+     * Get a logger instance for a certain class, service or component.
+     *
+     * @param {string} className Name to use in the messages.
+     * @return {ant} Instance.
+     */
+    getInstance(className: string) : any {
+        className = className || '';
+
+        return {
+            log   : this.prepareLogFn(console.log.bind(console), className),
+            info  : this.prepareLogFn(console.info.bind(console), className),
+            warn  : this.prepareLogFn(console.warn.bind(console), className),
+            debug : this.prepareLogFn(console.debug.bind(console), className),
+            error : this.prepareLogFn(console.error.bind(console), className)
+        };
+    }
+
+    /**
+     * Prepare a logging function, concatenating the timestamp and class name to all messages.
+     *
+     * @param {Function} logFn Log function to use.
+     * @param {string} className Name to use in the messages.
+     * @return {Function} Prepared function.
+     */
+    private prepareLogFn(logFn: Function, className: string) : Function {
+        // Return our own function that will call the logging function with the treated message.
+        return (...args) => {
+            if (this.enabled) {
+                let now  = moment().format('l LTS');
+
+                args[0] = now + ' ' + className + ': ' + args[0]; // Prepend timestamp and className to the original message.
+                logFn.apply(null, args);
+            }
+        };
+    }
+}