gpii-windows/gpii/node_modules/gpii-service-handler/src/requestHandler.js

Components of the GPII personalization infrastructure for use on Microsoft's "Windows" ™

/*
 * Handles requests from Windows Service.
 *
 * Copyright 2018 Raising the Floor - International
 *
 * Licensed under the New BSD license. You may not use this file except in
 * compliance with this License.
 *
 * The R&D leading to these results received funding from the
 * Department of Education - Grant H421A150005 (GPII-APCP). However,
 * these results do not necessarily represent the policy of the
 * Department of Education, and you should not assume endorsement by the
 * Federal Government.
 *
 * You may obtain a copy of the License at
 * https://github.com/GPII/universal/blob/master/LICENSE.txt
 */

"use strict";

var fluid = require("gpii-universal");

var gpii = fluid.registerNamespace("gpii");
fluid.registerNamespace("gpii.windows.service.serviceHandler");

/**
 * A request from the service.
 * @typedef {Object} ServiceRequest
 * @property {String} requestType The type of request to perform.
 * @property {Mixed} [various] Zero or more additional fields specific to the request.
 */

// Handles requests from the service.
// handleRequest() is invoked when a ServiceRequest is received from the service. The requestType field of the
// ServiceRequest is used to determine which invoker to call, and the return value is returned.
fluid.defaults("gpii.windows.service.requestHandler", {
    gradeNames: ["fluid.component" ],
    invokers: {
        // Called from the handleMessage callback of the message session when a request has been received.
        handleRequest: {
            funcName: "gpii.windows.service.handleRequest",
            args: [ "{that}", "{arguments}.0" ] // ServiceRequest
        },
        // Dynamically called via handleRequest.
        status: {
            funcName: "gpii.windows.service.status",
            args: [ "{that}" ]
        },
        shutdown: {
            funcName: "gpii.windows.service.shutdown",
            args: [ "{that}" ]
        }
    }
});

/**
 * Handle a request from the service, by calling the relevant invoker of gpii.windows.service.requestHandler.
 *
 * @param {Component} that The gpii.serviceHandler instance.
 * @param {ServiceRequest} request The request from the service.
 * @return {Object|Promise} The return of the handler function.
 */
gpii.windows.service.handleRequest = function (that, request) {
    fluid.log("Service: request", request);
    var handler = that[request.requestType];
    return typeof(handler) === "function" && handler(request);
};

/**
 * Determines the status of GPII. Currently, this only determines if GPII is running and hasn't frozen, where if a
 * response from this request hasn't been received in a timely manner then it can be assumed GPII has froze.
 *
 * @return {Object} an object containing the status.
 */
gpii.windows.service.status = function () {
    return {
        isRunning: true
    };
};

/**
 * Called by the service to shutdown GPII.
 */
gpii.windows.service.shutdown = function () {
    fluid.log("Service requested shutdown");
    gpii.windows.messages.sendMessage("gpii-message-window", gpii.windows.API_constants.WM_QUERYENDSESSION, 0, 0);
};