Documentation

Using Routes with a Basic Remote App

Remote Apps use Liferay’s front-end infrastructure to register external applications with the Liferay platform and render them as widgets. For applications that include multiple routes (e.g., React Router, you can define remote app properties to determine which routes are used for a widget at runtime. These properties can be set for an application via Remote Apps or the widget’s configuration options once deployed.

In this tutorial, you’ll create a basic React application using Liferay’s create_remote_app.sh script, which generates a sample app with three routes: hello-world, hello-foo, hello-bar. After compiling the application and hosting its .js and .css files, you’ll register the application with Remote Apps and deploy it as a Page widget. Finally, you’ll configure it to use each of the alternative routes.

Create a basic remote app with alternate routes and use the route property to configure which is rendered.

Note

Liferay Remote Apps is agnostic regarding how applications are built, packaged, and hosted. This tutorial only offers a convenient way to create a sample remote application with basic routing.

Running create_remote_app.sh requires the latest versions of Node.JS, NPM, and YARN. Before proceeding, ensure these tools are installed.

Creating, Building, and Hosting the React Application

  1. Start a new Liferay DXP 7.4+ container. You can continue to the next steps while the container starts.

    docker run -it -m 8g -p 8080:8080 liferay/dxp:7.4.13-u29
    
  2. Run this command in a separate terminal to generate the React application.

    curl -Ls https://github.com/liferay/liferay-portal/raw/master/tools/create_remote_app.sh | bash -s j1v3-remote-app react
    
  3. Verify the application was created successfully.

    The script should create a new React application called j1v3-remote-app that includes the following elements:

    j1v3-remote-app
    ├── node_modules
    ├── README.md
    ├── package.json
    ├── public
    │   └── index.html
    ├── src
    │   ├── common
    │   │   ├── services
    │   │   │   └── liferay
    │   │   │       ├── api.js
    │   │   │       └── liferay.js
    │   │   └── styles
    │   │       ├── hello-world.scss
    │   │       ├── index.scss
    │   │       └── variables.scss
    │   ├── index.js
    │   └── routes
    │       ├── hello-bar
    │       │   └── pages
    │       │       └── HelloBar.js
    │       ├── hello-foo
    │       │   └── pages
    │       │       └── HelloFoo.js
    │       └── hello-world
    │           └── pages
    │               └── HelloWorld.js
    └── yarn.lock
    
  4. Navigate to the new j1v3-remote-app folder and build the application.

    cd j1v3-remote-app
    
    yarn build
    
  5. Verify the build succeeded and take note of the application’s .js and .css files.

    Creating an optimized production build...
    Compiled successfully.
    
    File sizes after gzip:
    
    43.51 kB  build/static/js/main.114dde4a.js
    121 B     build/static/css/main.9877909d.css
    
  6. Sign in to Liferay at <http://localhost:8080> using the email address test@liferay.com and the password test. When prompted, change the password to learn.

  7. Open the Site Menu (Site Menu), expand Content & Data, and go to Documents and Media.

  8. Click the Add button (Add Button) and select Multiple Files Upload.

  9. Drag and drop the .js and .css files into the upload area.

    Upload the .js and .css files to the Liferay Document Library.

  10. Click Publish.

This adds the files to the Liferay Document Library and assigns them unique WebDAV URLs, which you’ll use to create the remote app.

Tip

This tutorial hosts the application’s static resources in Liferay’s Document Library for demonstration purposes. In a production environment, you should host the application’s files on a server optimized for hosting static resources.

To view each file’s URL, click the Info icon (Info Icon) and select one of the files at a time. Copy each file’s WebDAV URL and save them for use in the next step.

Copy each file's WebDAV URL.

For example,

  • http://localhost:8080/webdav/guest/document_library/main.114dde4a.js

  • http://localhost:8080/webdav/guest/document_library/main.9877909d.css

Registering and Deploying the Remote App

  1. Open the Global Menu (Global Menu), click on the Applications tab, and go to Remote Apps.

  2. Click the Add button (Add Button).

  3. Enter these values:

    Field

    Value

    Name

    J1V3-Remote-App

    Type

    Custom Element

    HTML Element Name

    j1v3-remote-app

    URL

    WebDAV URL for the .js file

    CSS URL

    WebDAV URL for the .css file

    Instanceable

    Portlet Category Name

    Remote Apps

  4. Click Save.

Once saved, Liferay creates a widget named J1V3-Remote-App, which you can deploy to Site Pages like any other Page widget. It appears under the selected Portlet Category Name.

Since J1V3-Remote-App is instanceable, you can add many of them to a page, each with its own independent configuration. For this tutorial, add the widget to a page twice.

Deploy two instances of the J1V3-Remote-App widget.

Using the route Property

The auto-generated app includes three routes: hello-world, hello-foo, hello-bar. By default the application uses the hello-world route. However, you can use remote app properties to configure it to use an alternate route. You can set these properties via Remote Apps or a widget’s configuration options.

Defining a Route Property via Remote Apps

  1. Open the Global Menu (Global Menu), click on the Applications tab, and go to Remote Apps.

  2. Select J1V3-Remote-App.

    Select J1V3-Remote-App.

  3. Enter route=hello-foo into the Properties field.

    Enter route=hello-foo into the Properties field.

  4. Click Publish.

  5. Verify both deployed widgets use the HelloFoo route.

    Verify both widgets use the HelloFoo route.

Defining a Route Property via Widget Configuration

  1. Edit the Page containing the J1V3-Remote-App widgets.

  2. Click the Options button (Options Button) for one of the widgets and select Configuration.

    Click the Options button and select Configuration.

  3. Enter route=hello-bar into the Properties field.

    Enter route=hello-bar into the Properties field.

  4. Click Save.

  5. Verify the configured widget uses the hello-bar route, while the other widget still uses the hello-foo route.

    Verify the configured widget uses the HelloBar route.

Analyzing the Route Code

import React from 'react';
import ReactDOM from 'react-dom';

import HelloBar from './routes/hello-bar/pages/HelloBar';
import HelloFoo from './routes/hello-foo/pages/HelloFoo';
import HelloWorld from './routes/hello-world/pages/HelloWorld';
import './common/styles/index.scss';

const App = ({ route }) => {
	if (route === "hello-bar") {
		return <HelloBar />;
	}

	if (route === "hello-foo") {
		return <HelloFoo />;
	}

	return <HelloWorld />;
};

class WebComponent extends HTMLElement {
	connectedCallback() {
		ReactDOM.render(
			<App route={this.getAttribute("route")} />,
			this
		);
	}
}

const ELEMENT_ID = 'j1v3-remote-app';

if (!customElements.get(ELEMENT_ID)) {
	customElements.define(ELEMENT_ID, WebComponent);
}

This index.js file creates the WebComponent class, which extends the HTMLElement interface. This class implements the interface’s connectedCallback() function, which calls ReactDOM.render with App as a parameter. When App is called, it checks for any defined "route" attribute and compares that value with the available routes. If it matches either hello-foo or hello-bar, then it returns and renders the corresponding route. Otherwise, it returns and renders hello-world.

Each of the routes is imported into the index.js file from the routes folder:

routes
├── hello-bar
│   └── pages
│       └── HelloBar.js
├── hello-foo
│   └── pages
│       └── HelloFoo.js
└── hello-world
    └── pages
        └── HelloWorld.js

HelloWorld.js

import React from 'react';

const HelloWorld = () => (
	<div className="hello-world">
		<h1>Hello World</h1>
	</div>
);

export default HelloWorld;

HelloFoo.js

import React from 'react';

const HelloFoo = () => (
	<div className="hello-foo">
		<h1>Hello Foo</h1>
	</div>
);

export default HelloFoo;

HelloBar.js

import React from 'react';

const HelloBar = () => (
	<div className="hello-bar">
		<h1>Hello Bar</h1>
	</div>
);

export default HelloBar;