[Import/Export] Adds Import and Export functionality

Added context actions for importing and exporting JSON representations of domain objects. Added FileInputService for triggering file picker and retrieving uploaded data. Also added a File Input form control for integration with MCTForms.

platform/forms/src/FileInputService.js

@@ -0,0 +1,90 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2017, 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.
+ *****************************************************************************/
+
+define(["zepto"], function ($) {
+
+    /**
+     * The FileInputService provides an interface for triggering a file input.
+     *
+     * @constructor
+     * @memberof platform/forms
+     */
+    function FileInputService() {
+
+    }
+
+    /**
+     * Creates, triggers, and destroys a file picker element and returns a
+     * promise for an object containing the chosen file's name and contents.
+     *
+     * @returns {Promise} promise for an object containing file meta-data
+     */
+    FileInputService.prototype.getInput = function () {
+        var input = this.newInput();
+        var read = this.readFile;
+        var fileInfo = {};
+        var file;
+
+        return new Promise(function (resolve, reject) {
+            input.trigger("click");
+            input.on('change', function (event) {
+                file = this.files[0];
+                input.remove();
+                if (file) {
+                    read(file)
+                        .then(function (contents) {
+                            fileInfo.name = file.name;
+                            fileInfo.body = contents;
+                            resolve(fileInfo);
+                        }, function () {
+                            reject("File read error");
+                        });
+                }
+            });
+        });
+    };
+
+    FileInputService.prototype.readFile = function (file) {
+        var fileReader = new FileReader();
+
+        return new Promise(function (resolve, reject) {
+            fileReader.onload = function (event) {
+                resolve(event.target.result);
+            };
+
+            fileReader.onerror = function () {
+                return reject(event.target.result);
+            };
+            fileReader.readAsText(file);
+        });
+    };
+
+    FileInputService.prototype.newInput  = function () {
+        var input = $(document.createElement('input'));
+        input.attr("type", "file");
+        input.css("display", "none");
+        $('body').append(input);
+        return input;
+    };
+
+    return FileInputService;
+});