[UserAPI] [UserIndicator Plugin] [ExampleUserProvider Plugin] New user api and related functionality (#4538)

* Implements User API and example user plugin

Co-authored-by: John Hill <john.c.hill@nasa.gov>
Co-authored-by: Charles Hacskaylo <charlesh88@gmail.com>
Co-authored-by: Andrew Henry <akhenry@gmail.com>

example/exampleUser/ExampleUserProvider.js

@@ -0,0 +1,110 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2021, 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';
+import uuid from 'uuid';
+import createExampleUser from './exampleUserCreator';
+
+export default class ExampleUserProvider extends EventEmitter {
+    constructor(openmct) {
+        super();
+
+        this.openmct = openmct;
+        this.user = undefined;
+        this.loggedIn = false;
+        this.autoLoginUser = undefined;
+
+        this.ExampleUser = createExampleUser(this.openmct.user.User);
+    }
+
+    isLoggedIn() {
+        return this.loggedIn;
+    }
+
+    autoLogin(username) {
+        this.autoLoginUser = username;
+    }
+
+    getCurrentUser() {
+        if (this.loggedIn) {
+            return Promise.resolve(this.user);
+        }
+
+        return this._login().then(() => this.user);
+    }
+
+    hasRole(roleId) {
+        if (!this.loggedIn) {
+            Promise.resolve(undefined);
+        }
+
+        return Promise.resolve(this.user.getRoles().includes(roleId));
+    }
+
+    _login() {
+        const id = uuid();
+
+        // for testing purposes, this will skip the form, this wouldn't be used in
+        // a normal authentication process
+        if (this.autoLoginUser) {
+            this.user = new this.ExampleUser(id, this.autoLoginUser, ['example-role']);
+            this.loggedIn = true;
+
+            return Promise.resolve();
+        }
+
+        const formStructure = {
+            title: "Login",
+            sections: [
+                {
+                    rows: [
+                        {
+                            key: "username",
+                            control: "textfield",
+                            name: "Username",
+                            pattern: "\\S+",
+                            required: true,
+                            cssClass: "l-input-lg",
+                            value: ''
+                        }
+                    ]
+                }
+            ],
+            buttons: {
+                submit: {
+                    label: 'Login'
+                }
+            }
+        };
+
+        return this.openmct.forms.showForm(formStructure).then(
+            (info) => {
+                this.user = new this.ExampleUser(id, info.username, ['example-role']);
+                this.loggedIn = true;
+            },
+            () => { // user canceled, setting a default username
+                this.user = new this.ExampleUser(id, 'Pat', ['example-role']);
+                this.loggedIn = true;
+            }
+        );
+    }
+}