BrowserChannel.js

/*!
  GPII BrowserChannel Handler

  Copyright 2014, 2015 Emergya
  Copyright 2015-2018 Raising the Floor - International
  Copyright 2020 OCAD University

  Licensed under the New BSD license. You may not use this file except in
  compliance with this License.

  You may obtain a copy of the License at
  https://github.com/gpii/universal/LICENSE.txt
*/

"use strict";

var fluid = require("infusion");
var gpii = fluid.registerNamespace("gpii");

fluid.registerNamespace("gpii.flowManager");

fluid.defaults("gpii.flowManager.browserChannel", {
    gradeNames: ["fluid.modelComponent"]
});

fluid.defaults("gpii.flowManager.browserChannel.handler", {
    gradeNames: ["kettle.request.ws", "gpii.flowManager.sessionAware"],
    listeners: {
        onReceiveMessage: {
            funcName: "gpii.flowManager.browserChannel.receiveMessage",
            args: [
                "{that}",
                "{arguments}.1",
                "{flowManager}.solutionsRegistryDataSource",
                "{deviceReporter}.platformReporter"
            ]
        }
    }
});

/**
 * Send an error response for the request.
 * @param {Component} request - An instance of gpii.flowManager.browserChannel.handler.
 * @param {String} message - Error message text to include in the response.
 */
gpii.flowManager.browserChannel.sendError = function (request, message) {
    fluid.log("Sending browserChannel error ", message);
    var error = {
        isError: true,
        message: message
    };
    request.sendMessage(error);
    // These codes bizarrely are not HTTP codes, but listed here: https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent
    request.ws.close(1008, "Solution id not authorized");
};

/**
 * Handler for all message types:
 * - an initial "connect" message type establishes the connection and
 *   initializes the channel and its relationship with the WebSockets settings
 *   handler.  This includes dynamically attaching the
 *   gpii.flowManager.browserChannel.receiveChangeSettingsMsg() listener to
 *   handle "changeSettings" message types after the connection is established.
 * - any subsequent "connect" message types are silently ignored,
 * - all other message types cause an error response and close the connection
 *   The one exception is the "changeSettings" message type (see first point).
 * @param {Component} that - An instance of gpii.flowManager.browserChannel.handler.
 * @param {Object} message - Object containing the message type and its payload.
 * @param {Component} solutionsRegistryDataSource - Used to match the solution
 *                                                  given in the payload.
 * @param {Component} platformReporter - Used to determine the platform this
 *                                       is running on.
 */
gpii.flowManager.browserChannel.receiveMessage = function (that, message, solutionsRegistryDataSource, platformReporter) {
    if (message.type !== "connect") {
        return;
    }
    if (that.established) {
        gpii.flowManager.browserChannel.sendError(that, "Connection already established - cannot send a second connect message");
    }
    var solutionId = message.payload.solutionId;
    solutionsRegistryDataSource.get({os: platformReporter.reportPlatform().id}, function onSuccess(entries) {
        if (!(solutionId in entries)) {
            gpii.flowManager.browserChannel.sendError(that, "Rejecting a connection request from '" + solutionId +
                "'. The solution id was not found in the solutions registry");
        } else {
            gpii.settingsHandlers.webSockets.instance.addClient(solutionId, that);
            that.established = true;
            that.solutionId = solutionId;
        }
    }, function (error) {
        gpii.flowManager.browserChannel.sendError(that, error.message);
    });
};

/**
 * Listener for the "changeSettings" message type.  This is added as a listener
 * after the connection has been established.  That is, this will not function
 * without a previous "connect" message type.
 * @param {Component} that - An instance of gpii.flowManager.browserChannel.handler.
 * @param {Object} message - Object containing the message type and its payload.
 */
gpii.flowManager.browserChannel.receiveChangeSettingsMsg = function (that, message) {
    if (message.type === "changeSettings" && that.established) {
        var wsPayload = {};
        wsPayload[that.solutionId] = [{
            options: {
                path: that.solutionId,
                source: that
            },
            settings: message.payload.settings
        }];
        gpii.settingsHandlers.webSockets.set(wsPayload);
    }
};