MOBILE-2330 question: Implement question behaviour delegate

src/core/question/providers/behaviour-delegate.ts

@@ -0,0 +1,112 @@
+// (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 { CoreLoggerProvider } from '@providers/logger';
+import { CoreEventsProvider } from '@providers/events';
+import { CoreSitesProvider } from '@providers/sites';
+import { CoreDelegate, CoreDelegateHandler } from '@classes/delegate';
+import { CoreQuestionState } from './question';
+import { CoreQuestionDelegate } from './delegate';
+import { CoreQuestionBehaviourDefaultHandler } from './default-behaviour-handler';
+
+/**
+ * Interface that all question behaviour handlers must implement.
+ */
+export interface CoreQuestionBehaviourHandler extends CoreDelegateHandler {
+    /**
+     * Type of the behaviour the handler supports. E.g. 'adaptive'.
+     * @type {string}
+     */
+    type: string;
+
+    /**
+     * Determine a question new state based on its answer(s).
+     *
+     * @param {string} component Component the question belongs to.
+     * @param {number} attemptId Attempt ID the question belongs to.
+     * @param {any} question The question.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {CoreQuestionState|Promise<CoreQuestionState>} State (or promise resolved with state).
+     */
+    determineNewState?(component: string, attemptId: number, question: any, siteId?: string)
+        : CoreQuestionState | Promise<CoreQuestionState>;
+
+    /**
+     * Handle a question behaviour.
+     * If the behaviour requires a submit button, it should add it to question.behaviourButtons.
+     * If the behaviour requires to show some extra data, it should return the components to render it.
+     *
+     * @param {any} question The question.
+     * @return {any[]|Promise<any[]>} Components (or promise resolved with components) to render some extra data in the question
+     *                                (e.g. certainty options). Don't return anything if no extra data is required.
+     */
+    handleQuestion?(question: any): any[] | Promise<any[]>;
+}
+
+/**
+ * Delegate to register question behaviour handlers.
+ */
+@Injectable()
+export class CoreQuestionBehaviourDelegate extends CoreDelegate {
+
+    protected handlerNameProperty = 'type';
+
+    constructor(logger: CoreLoggerProvider, sitesProvider: CoreSitesProvider, eventsProvider: CoreEventsProvider,
+            protected questionDelegate: CoreQuestionDelegate, protected defaultHandler: CoreQuestionBehaviourDefaultHandler) {
+        super('CoreQuestionBehaviourDelegate', logger, sitesProvider, eventsProvider);
+    }
+
+    /**
+     * Determine a question new state based on its answer(s).
+     *
+     * @param {string} component Component the question belongs to.
+     * @param {number} attemptId Attempt ID the question belongs to.
+     * @param {any} question The question.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {Promise<CoreQuestionState>} Promise resolved with state.
+     */
+    determineNewState(behaviour: string, component: string, attemptId: number, question: any, siteId?: string)
+            : Promise<CoreQuestionState> {
+        behaviour = this.questionDelegate.getBehaviourForQuestion(question, behaviour);
+
+        return Promise.resolve(this.executeFunctionOnEnabled(behaviour, 'determineNewState',
+                [component, attemptId, question, siteId]));
+    }
+
+    /**
+     * Handle a question behaviour.
+     * If the behaviour requires a submit button, it should add it to question.behaviourButtons.
+     * If the behaviour requires to show some extra data, it should return a directive to render it.
+     *
+     * @param {string} behaviour Default behaviour.
+     * @param {any} question The question.
+     * @return {Promise<any[]>} Promise resolved with components to render some extra data in the question.
+     */
+    handleQuestion(behaviour: string, question: any): Promise<any[]> {
+        behaviour = this.questionDelegate.getBehaviourForQuestion(question, behaviour);
+
+        return Promise.resolve(this.executeFunctionOnEnabled(behaviour, 'handleQuestion', [question]));
+    }
+
+    /**
+     * Check if a question behaviour is supported.
+     *
+     * @param {string} behaviour Name of the behaviour.
+     * @return {boolean} Whether it's supported.
+     */
+    isBehaviourSupported(behaviour: string): boolean {
+        return this.hasHandler(behaviour, true);
+    }
+}

src/core/question/providers/default-behaviour-handler.ts

@@ -0,0 +1,66 @@
+// (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 { CoreQuestionBehaviourHandler } from './behaviour-delegate';
+import { CoreQuestionProvider, CoreQuestionState } from '@core/question/providers/question';
+
+/**
+ * Default handler used when the question behaviour doesn't have a specific implementation.
+ */
+@Injectable()
+export class CoreQuestionBehaviourDefaultHandler implements CoreQuestionBehaviourHandler {
+    name = 'CoreQuestionBehaviourDefault';
+    type = 'default';
+
+    constructor(private questionProvider: CoreQuestionProvider) { }
+
+    /**
+     * Determine a question new state based on its answer(s).
+     *
+     * @param {string} component Component the question belongs to.
+     * @param {number} attemptId Attempt ID the question belongs to.
+     * @param {any} question The question.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {CoreQuestionState|Promise<CoreQuestionState>} New state (or promise resolved with state).
+     */
+    determineNewState(component: string, attemptId: number, question: any, siteId?: string)
+            : CoreQuestionState | Promise<CoreQuestionState> {
+        // Return the current state.
+        return this.questionProvider.getState(question.state);
+    }
+
+    /**
+     * Handle a question behaviour.
+     * If the behaviour requires a submit button, it should add it to question.behaviourButtons.
+     * If the behaviour requires to show some extra data, it should return the components to render it.
+     *
+     * @param {any} question The question.
+     * @return {any[]|Promise<any[]>} Components (or promise resolved with components) to render some extra data in the question
+     *                                (e.g. certainty options). Don't return anything if no extra data is required.
+     */
+    handleQuestion(question: any): any[] | Promise<any[]> {
+        // Nothing to do.
+        return;
+    }
+
+    /**
+     * Whether or not the handler is enabled on a site level.
+     *
+     * @return {boolean|Promise<boolean>} True or promise resolved with true if enabled.
+     */
+    isEnabled(): boolean | Promise<boolean> {
+        return true;
+    }
+}

src/core/question/question.module.ts

@@ -15,12 +15,15 @@
 import { NgModule } from '@angular/core';
 import { CoreQuestionProvider } from './providers/question';
 import { CoreQuestionDelegate } from './providers/delegate';
+import { CoreQuestionBehaviourDelegate } from './providers/behaviour-delegate';
 import { CoreQuestionDefaultHandler } from './providers/default-question-handler';
+import { CoreQuestionBehaviourDefaultHandler } from './providers/default-behaviour-handler';
 
 // List of providers (without handlers).
 export const CORE_QUESTION_PROVIDERS: any[] = [
     CoreQuestionProvider,
-    CoreQuestionDelegate
+    CoreQuestionDelegate,
+    CoreQuestionBehaviourDelegate
 ];
 
 @NgModule({
@@ -28,7 +31,8 @@ export const CORE_QUESTION_PROVIDERS: any[] = [
     imports: [
     ],
     providers: CORE_QUESTION_PROVIDERS.concat([
-        CoreQuestionDefaultHandler
+        CoreQuestionDefaultHandler,
+        CoreQuestionBehaviourDefaultHandler
     ]),
     exports: []
 })