Visiting invalid URLs and bad APIs causes redirect to error page

webapp/components/error_page.jsx

@@ -0,0 +1,58 @@
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+import $ from 'jquery';
+
+import React from 'react';
+import {Link} from 'react-router';
+
+import * as Utils from 'utils/utils.jsx';
+
+export default class ErrorPage extends React.Component {
+    componentDidMount() {
+        $('body').attr('class', 'sticky error');
+    }
+    componentWillUnmount() {
+        $('body').attr('class', '');
+    }
+    render() {
+        let title = this.props.location.query.title;
+        if (!title || title === '') {
+            title = Utils.localizeMessage('error.generic.title', 'Error');
+        }
+
+        let message = this.props.location.query.message;
+        if (!message || message === '') {
+            message = Utils.localizeMessage('error.generic.message', 'An error has occoured.');
+        }
+
+        let link = this.props.location.query.link;
+        if (!link || link === '') {
+            link = '/';
+        }
+
+        let linkMessage = this.props.location.query.linkmessage;
+        if (!linkMessage || linkMessage === '') {
+            linkMessage = Utils.localizeMessage('error.generic.link_message', 'Back to Mattermost');
+        }
+
+        return (
+            <div className='container-fluid'>
+                <div className='error__container'>
+                    <div className='error__icon'>
+                        <i className='fa fa-exclamation-triangle'/>
+                    </div>
+                    <h2>{title}</h2>
+                    <p>{message}</p>
+                    <Link to={link}>{linkMessage}</Link>
+                </div>
+            </div>
+        );
+    }
+}
+
+ErrorPage.defaultProps = {
+};
+ErrorPage.propTypes = {
+    location: React.PropTypes.object
+};