ECOM-4904 Move the program editor backbone app to Studio (#12962)

cms/static/js/programs/utils/auth_utils.js

@@ -0,0 +1,89 @@
+define([
+        'jquery',
+        'underscore',
+        'js/programs/utils/api_config'
+    ],
+    function( $, _, apiConfig ) {
+        'use strict';
+
+        var auth = {
+            autoSync: {
+                /**
+                 * Override Backbone.sync to seamlessly attempt (re-)authentication when necessary.
+                 *
+                 * If a 401 error response is encountered while making a request to the Programs,
+                 * API, this wrapper will attempt to request an id token from a custom endpoint
+                 * via AJAX.  Then the original request will be retried once more.
+                 *
+                 * Any other response than 401 on the original API request, or any error occurring
+                 * on the retried API request (including 401), will be handled by the base sync
+                 * implementation.
+                 *
+                 */
+                sync: function( method, model, options ) {
+
+                    var oldError = options.error;
+
+                    this._setHeaders( options );
+
+                    options.notifyOnError = false;  // suppress Studio error pop-up that will happen if we get a 401
+
+                    options.error = function(xhr, textStatus, errorThrown) {
+                        if (xhr && xhr.status === 401) {
+                            // attempt auth and retry
+                            this._updateToken(function() {
+                                // restore the original error handler
+                                options.error = oldError;
+                                options.notifyOnError = true;  // if it fails again, let Studio notify.
+                                delete options.xhr;  // remove the failed (401) xhr from the last try.
+
+                                // update authorization header
+                                this._setHeaders( options );
+
+                                Backbone.sync.call(this, method, model, options);
+                            }.bind(this));
+                        } else if (oldError) {
+                            // fall back to the original error handler
+                            oldError.call(this, xhr, textStatus, errorThrown);
+                        }
+                    }.bind(this);
+                    return Backbone.sync.call(this, method, model, options);
+                },
+
+                /**
+                 * Fix up headers on an imminent AJAX sync, ensuring that the JWT token is enclosed
+                 * and that credentials are included when the request is being made cross-domain.
+                 */
+                _setHeaders: function( ajaxOptions ) {
+                    ajaxOptions.headers = _.extend ( ajaxOptions.headers || {}, {
+                        Authorization: 'JWT ' + apiConfig.get( 'idToken' )
+                    });
+                    ajaxOptions.xhrFields = _.extend( ajaxOptions.xhrFields || {}, {
+                        withCredentials: true
+                    });
+                },
+
+                /**
+                 * Fetch a new id token from the configured endpoint, update the api config,
+                 * and invoke the specified callback.
+                 */
+                _updateToken: function( success ) {
+
+                    $.ajax({
+                        url: apiConfig.get('authUrl'),
+                        xhrFields: {
+                            // See: https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/withCredentials
+                            withCredentials: true
+                        },
+                        crossDomain: true
+                    }).done(function ( data ) {
+                        // save the newly-retrieved id token
+                        apiConfig.set( 'idToken', data.id_token );
+                    }).done( success );
+                }
+            }
+        };
+
+        return auth;
+    }
+);