@oat-sa/tao-test-runner-qti/src/provider/toolStateBridge.js

TAO Test Runner QTI implementation

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; under version 2
 * of the License (non-upgradable).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2018 (original work) Open Assessment Technologies SA
 *
 */

/**
 * Manages to restore and retrieve the states of the tools.
 * The main purpose is to wrap the check and wrap calls to the testStore.
 *
 * ONE TOOL  => ONE PLUGIN
 * TOOL_NAME => PLUGIN_NAME
 *
 * @author Bertrand Chevrier <bertrand@taotesting.com>
 */
import _ from 'lodash';

/**
 * Merge each item of a collection with the next
 * @param {Object[]} collection
 * @return {Object} the merged collection
 */
var mergeCollection = function mergeCollection(collection) {
    return _.reduce(
        collection,
        function (acc, value) {
            if (value) {
                return _.merge(acc, value);
            }
            return acc;
        },
        {}
    );
};

/**
 * Build the toolStateBridge instance.
 *
 *
 * In order to allow state management for a tool the matching plugin
 * needs to be activated.
 *
 * @param {testStore} testStore - the testStore instance
 * @param {String[]} activePlugins - the list of active plugins
 * @returns {toolStateBridge}
 */
export default function toolStateBridgeFactory(testStore, activePlugins) {
    var tools = [];

    if (!testStore || !_.isFunction(testStore.getStore)) {
        throw new TypeError('The toolStateBridge should be initialized with a testStore');
    }
    if (!_.isArray(activePlugins) || !activePlugins.length) {
        throw new TypeError('The toolStateBridge should be initialized with a the list of active plugins');
    }

    /**
     * @typedef {Object} toolStateBridge
     */
    return {
        /**
         * Set the tools to manage the states.
         * Each toolName MUST match a plugin name.
         *
         * This trigger the change tracking in the testStore for the
         * stores with the tool/plugin name.
         *
         * @param {String[]} toolNames - the list of tool names
         * @returns {toolStateBridge} chains
         */
        setTools: function setTools(toolNames) {
            tools = _(toolNames)
                .filter(function (toolName) {
                    return activePlugins.includes(toolName);
                })
                .map(function (toolName) {
                    testStore.startChangeTracking(toolName);
                    return toolName;
                })
                .value();
            return this;
        },

        /**
         * Get the list of tools
         * @returns {String[]} the list of configured tools
         */
        getTools: function getTools() {
            return tools;
        },

        /**
         * Restore the state of the given tool
         * @param {String} toolName - the name of the tool
         * @param {Object} toolState - the state to restore
         * @returns {Promise<Boolean>} resolves with true if restored
         */
        restoreState: function restoreState(toolName, toolState) {
            if (tools.includes(toolName) && _.isPlainObject(toolState)) {
                return testStore
                    .getStore(toolName)
                    .then(function (toolStore) {
                        return toolStore.clear().then(function () {
                            return toolStore;
                        });
                    })
                    .then(function (toolStore) {
                        return Promise.all(
                            _.map(toolState, function (value, key) {
                                return toolStore.setItem(key, value);
                            })
                        );
                    })
                    .then(function () {
                        testStore.resetChanges(toolName);
                        return true;
                    });
            }
            return Promise.resolve(false);
        },

        /**
         * Restore the states of multiple tools
         * @param {Object} states - key is the toolName and the value the state to resolve
         * @returns {Promise<Object>} key is the restored toolName and the value is the status
         */
        restoreStates: function restoreStates(states) {
            var self = this;
            return Promise.all(
                _.map(states, function (toolState, toolName) {
                    return self.restoreState(toolName, toolState).then(function (result) {
                        var formattedResult = {};
                        formattedResult[toolName] = result;
                        return formattedResult;
                    });
                })
            ).then(mergeCollection);
        },

        /**
         * Get the state of a given tool
         * @param {String} toolName - the name of the tool
         * @param {Boolean} [reset] - do we reset the change tracking ?
         * @returns {Promise<Object|Boolean>} resolves with the state
         */
        getState: function getState(toolName, reset) {
            if (tools.includes(toolName) && testStore.hasChanges(toolName)) {
                return testStore.getStore(toolName).then(function (toolStore) {
                    if (reset !== false) {
                        testStore.resetChanges(toolName);
                    }
                    return toolStore.getItems();
                });
            }
            return Promise.resolve(false);
        },

        /**
         * Get the state for all tools with changes
         * @returns {Promise<Object>} resolves with the states
         */
        getStates: function getStates() {
            var self = this;
            return Promise.all(
                _.map(tools, function (toolName) {
                    return self.getState(toolName).then(function (toolState) {
                        //format the state to keep the tool identifier
                        var formattedState = {};
                        if (toolState) {
                            formattedState[toolName] = toolState;
                            return formattedState;
                        }
                        return false;
                    });
                })
            ).then(mergeCollection);
        }
    };
}