openmct/src/api/Editor.js

/*****************************************************************************
 * Open MCT, Copyright (c) 2014-2022, United States Government
 * as represented by the Administrator of the National Aeronautics and Space
 * Administration. All rights reserved.
 *
 * Open MCT is 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.
 *
 * Open MCT includes source code licensed under additional open source
 * licenses. See the Open Source Licenses file (LICENSES.md) included with
 * this source code distribution or the Licensing information page available
 * at runtime from the About dialog for additional information.
 *****************************************************************************/

import EventEmitter from 'EventEmitter';

export default class Editor extends EventEmitter {
    constructor(openmct) {
        super();
        this.editing = false;
        this.openmct = openmct;
    }

    /**
     * Initiate an editing session. This will start a transaction during
     * which any persist operations will be deferred until either save()
     * or finish() are called.
     */
    edit() {
        if (this.editing === true) {
            throw "Already editing";
        }

        this.editing = true;
        this.emit('isEditing', true);
        this.openmct.objects.startTransaction();
    }

    /**
     * @returns true if the application is in edit mode, false otherwise.
     */
    isEditing() {
        return this.editing;
    }

    /**
     * Save any unsaved changes from this editing session. This will
     * end the current transaction.
     */
    save() {
        const transaction = this.openmct.objects.getActiveTransaction();

        return transaction.commit()
            .then(() => {
                this.editing = false;
                this.emit('isEditing', false);
                this.openmct.objects.endTransaction();
            }).catch(error => {
                throw error;
            });
    }

    /**
     * End the currently active transaction and discard unsaved changes.
     */
    cancel() {
        this.editing = false;
        this.emit('isEditing', false);

        return new Promise((resolve, reject) => {
            const transaction = this.openmct.objects.getActiveTransaction();
            transaction.cancel()
                .then(resolve)
                .catch(reject)
                .finally(() => {
                    this.openmct.objects.endTransaction();
                });
        });
    }
}