Adding a new React component in AFL

In this lesson, we will build a Hello World card as a React component and display it in an AFL portal workspace.

You will:

Write a Hello AFL portlet in React.
Expose the portlet to AFL using AMD (Asynchronous Module Definition).
Add the Hello AFL portlet to libexport.js so that webpack knows what to bundle.
Use webpack to bundle all developer defined portlets into reactComponents.js.
Reference the newly created Hello AFL portlet in a workspace.

Using webpack improves development velocity, since in development mode, it watches the changes to the portlet definitions and updates reactComponent.js. A browser refresh picks up the changes.

Note

If the directories mentioned in the following instructions don't exist, you will need to create them.

Learning activity

The react-components project is dependent on React, and is the main project that will be modified in this learning module.

In this learning activity, you will insert your new Hello AFL Portlet.

Press Ctrl+Shift+r and type react-components/meta/.metadata to open the .metadata file of the react-components project.
Add the following code to the Metadata element.
```
   <Mixins>
      <Mixin namespace="nexj:model:react"/>
   </Mixins>
```
The Mixin namespace added to the .metadata file above, is derived from the namespace in the react project's metadata file as seen in the following:
<Metadata name="React" namespace="nexj:model:react" revision="16.6.3" version="16.6.3"/>
Press Ctrl+Shift+r and type training/meta/.metadata to open the .metadata file of the training project.

If the react-component project has not already been added as a mixin to your training project, add it by inserting the following code into the Mixins element:

<Mixin namespace="nexj:model:react-components"/>

This makes the training project aware of the react-components project files. The resulting file should look similar to the following:

training/meta/.metadata

<Metadata baseChecksum="16858b84" baseNamespace="http://www.nexjsystems.com/ns/finance" baseVersion="1065.1307.165.53" name="training" namespace="nexj:training" revision="1.0" version="1.1065.1307.165.53">
   <Mixins>
      <Mixin namespace="nexj:openapi"/>
      <Mixin namespace="nexj:model:finance-md"/>
      <Mixin namespace="nexj:model:afl"/>
      <Mixin namespace="nexj:model:portal"/>
      <Mixin namespace="nexj:model:cpm"/>
      <Mixin namespace="nexj:model:highcharts"/>
      <Mixin namespace="nexj:model:ckeditor"/>
      <Mixin namespace="nexj:model:dai:nexjcdc"/>
      <Mixin namespace="nexj:model:libphonenum"/>
      <Mixin namespace="nexj:model:afl-mda"/>
      <Mixin namespace="nexj:model:react-components"/>
   </Mixins>
</Metadata>

Optional Read

This namespace was used as a mixin in the training project. If you press Ctrl+Shift+r, type react-components/meta/.metadata, and open the file, you should see the namespace.

Run the server console in NexJ Studio and in a browser, navigate to http://localhost:7080/training/ui/portal/training:React.
At a command prompt, navigate to c:\nexj_studio\13.0-training\training\models\react-components and run the following to get all the required dependencies ready for development:
```
npm install
```
Enter the following code to run the webpack build, and watch the process.
```
npm run build:afldev
```
You should see a "webpack is watching the files" message in the console as well as a new reactComponents.js file getting generated into the mod folder of the react-components project.

Create the Hello AFL portlet by adding a new Hello.js file in react-components/src/portlets with the following contents:

react-components/src/portlets

import PropTypes from 'prop-types';
import React from 'react';
 
function Hello(props) {
    const { EntityId, aflCallBack } = props;
    return (<div>Hello World </div>);
}
 
Hello.propTypes = {
  EntityId: PropTypes.string,
  aflCallBack: PropTypes.func,
};
 
Hello.defaultProps = {
  EntityId: null,
  aflCallBack: null,
};
 
export default Hello;

JSX is used in this React component, translation is handled by babel, and it is run by webpack as indicated in the following code snippet from react-components/config/webpack.js.

 presets: ['@babel/preset-env', '@babel/react'],

Make the hello.js portlet available to AFL using AMD by adding a new hello.js in react-components/src/app with the following contents:

react-components/src/app

/** Sample portlet in react, with "EntityId" context.*/
define("app/hello", ["nexj/ui", "ext/ui/react/portlet"
            , "nexj/ui/core" //plug-in for ui.Portlet et al.
            , "nexj/ui/bus"], //plug-in for ui.ContextValue
    function( ui, reactPortlet) {"use strict";
    return function() {
        var contextId = new ui.ContextValue("EntityId");
        console.log("about to create Hello portlet/table views, contextId = ", contextId);
        return ui("Portlet", {children: [
            ui(reactPortlet.Portlet, {
                contextId: contextId,
                reactComponentName: "Hello",
                aflCallBack: function (e){
                    console.log("outer afl callback, e = ", e);
                }
            })
        ]});
    };
});

Take note of the app/hello string in the define. You will use it when you reference this portlet in the workspace.

With the portlet created, you need to instruct webpack to use it in the reactComponents.js bundle. Open react-components/src/libexport.js.
The file should look like the code below.
react-components/src/libexport.js
```
export { default as Hello } from './portlets/Hello';
```
Before saving the file, observe the npm run console. Save the file.
webpack should have rebuilt reactComponent.js.
libexport.js was defined as an entry point in the webpack config in react-components/config/webpack.js.
react-components/config/webpack.js.
module.exports = { entry: './src/libexport.js', ...
Add the portlet into a workspace. Open training/meta/workspaces/training/React.workspace and switch to the source tab.

In the XML file, you should see Workspace, Page, Tab, and PortletRef elements. Insert the following code inside the Tab element and make it the top entry.

training/meta/workspaces/training/React.workspace

<PortletRef name="refHello" portlet="app/hello"/>

The resulting file should look like the following:

<Workspace caption="idsa.React.WorkspaceName" icon="icon:&#xE8D0;">
   <Page name="pageHome">
      <Tab caption="idsa.Portal.Summary" layout="cols:2 fluid:true" name="tabHome" type="grid">
         <PortletRef name="refHello" portlet="app/hello"/>
         <PortletRef name="refReact" portlet="app/react"/>
         <PortletRef layout="off:1" name="refBus" portlet="app/bus"/>
         <PortletRef layout="off:1" name="refEntityList" portlet="mda:EntityNavigator"/>
         <PortletRef name="refAFL" portlet="app/chart"/>
      </Tab>
   </Page>
</Workspace>

Test displaying your Hello World card by:
1. Pressing Ctrl+Shift+r, type training, and open the training.scm file.
2. Pressing Ctrl+A and Ctrl+U to run the entire script in the Scheme console.
  
  This is an important step in refreshing your workspace.
3. In your brower, refresh http://localhost:7080/training/ui/portal/training:React.
  
  For an added challenge, try to get Hello World to display as Hello along with the contact name in context.

Summary

In this lesson, we:

Created a React AFL portlet.
Exposed the portlet to AFL using AMD.
Added the React AFL portlet entry in libexport.js.
Referenced the name of the AMD in a Workspace.