Build Luigi App with React

In this step, you will create a file with information about the products on sale in your shopping app.

In a real life implementation, this data would be provided by an external service/API. But for simplicity, you will create a .js file containing dummy data. This file will provide the displayed data in the micro-frontend. You will create a similar file in the UI5 micro-frontend to avoid bundling issues.

1. Navigate to react-core-mf/src/assets and create a products.js file with the following content:

   JavaScript Copy

   export const ProductCollection = [
   {
       "id": 101,
       "name": "Mouse",
       "price": 45.0,
       "stock": 80,
       "icon": "product",
       "currencyCode": "EUR",
       "orderQuantity": 2,
       "description": "Wireless Gaming Mouse with Sensor"
   },
   {
       "id": 102,
       "name": "Keyboard",
       "price": 50.0,
       "stock": 22,
       "icon": "product",
       "currencyCode": "EUR",
       "orderQuantity": 1,
       "description": "A physical keyboard that uses an individual spring and switch for each key. Today, only premium keyboards are built with key switches."
   },
   {
       "id": 103,
       "name": "Optical Mouse",
       "price": 35.0,
       "stock": 4,
       "icon": "product",
       "currencyCode": "EUR",
       "orderQuantity": 2,
       "description": "Utilizing the latest optical sensing technology, the USB Optical Scroll Mouse records precise motion."
   },
   {
       "id": 104,
       "name": "Laptop Pro",
       "price": 1299.0,
       "stock": 11,
       "icon": "laptop",
       "currencyCode": "EUR",
       "orderQuantity": 3,
       "description": "Newest laptop featuring a touch-sensitive OLED display."
   },
   {
       "id": 105,
       "name": "Mouse 2",
       "price": 40.0,
       "stock": 20,
       "icon": "product",
       "currencyCode": "EUR",
       "orderQuantity": 6,
       "description": "The Mouse 2 is a computer mouse featuring a multi-touch acrylic surface for scrolling. The mouse features a lithium-ion rechargeable battery and Lightning connector for charging and pairing."
   },
   {
       "id": 106,
       "name": "Printer",
       "price": 235.0,
       "stock": 24,
       "icon": "fx",
       "currencyCode": "EUR",
       "orderQuantity": 1,
       "description": "Affordable printer providing you with the optimal way to take care of all your printing needs."
   },
   {
       "id": 107,
       "name": "Phone 11",
       "price": 835.0,
       "stock": 45,
       "icon": "iphone",
       "currencyCode": "EUR",
       "orderQuantity": 8,
       "description": "The Phone 11 dimensions are 150.9mm x 75.7mm x 8.3mm (H x W x D). It weighs about 194 grams (6.84 ounces)."
   },
   {
       "id": 108,
       "name": "Phone 3a",
       "price": 299.0,
       "stock": 54,
       "icon": "desktop-mobile",
       "currencyCode": "EUR",
       "orderQuantity": 7,
       "description": "At 5.6 inches, the display is proportionate to the relatively small body of the phone."
   },
   {
       "id": 109,
       "name": "Game Console 4",
       "price": 330.0,
       "stock": 94,
       "icon": "video",
       "currencyCode": "EUR",
       "orderQuantity": 1,
       "description": "This is the fourth home video game console compatible with all gaming systems."
   },
   {
       "id": 110,
       "name": "Monitor",
       "price": 630.0,
       "stock": 20,
       "icon": "sys-monitor",
       "currencyCode": "EUR",
       "orderQuantity": 3,
       "description": "34'' Monitor, Display with stand Height adjustable (115 mm), tiltable (-5° to 21°), rotatable (-30° to 30°) Security slot (cable lock sold separately), anti-theft slot for locking to stand (for display). Includes: DisplayPort cable, HDMI cable, Power cable, Stand, USB 3.0 Type-A to Type-B cable, USB-C cable."
   }

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]; ```

In this step, you will let Luigi take control of the index.html file - the entry point for your app.

1. Go to react-core-mf/public/index.html and change its content to:

   HTML Copy

   <!DOCTYPE html>
   <html>
     <head>
       <title>Luigi</title>
       <meta
         name="viewport"
         content="width=device-width, user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1"
       />
       <link rel="stylesheet" href="/luigi-core/luigi.css" />
     </head>
   
     <body>
       <noscript>You need to enable JavaScript to run this app.</noscript>
       <script src="/luigi-core/luigi.js"></script>
       <script src="/luigi-config.js"></script>
     </body>
   </html>

In this step, you will create another HTML file which will serve as a template for React to create the React micro-frontends.

1. Go to react-core-mf/public and create a new file called sampleapp.html. Paste this code into the file:

   HTML Copy

     <!DOCTYPE html>
     <html lang="en">
       <head>
         <meta charset="utf-8" />
         <link rel="icon" href="%PUBLIC_URL%/favicon.ico" />
         <meta name="viewport" content="width=device-width, initial-scale=1" />
         <title>React App</title>
       </head>
       <body>
         <noscript>You need to enable JavaScript to run this app.</noscript>
         <div id="root"></div>
       </body>
     </html>

In this step, you will configure webpack and adjust dependencies in order to make it easier to develop and build the app.

1. Go to react-core-mf/webpack.config.js. Note that by default the webpack-dev-server will redirect all requests to index.html which is the app’s main entry point where the Luigi Core library is injected. However, since the micro-frontends are also built in the same environment, it’s necessary to host the root React micro-frontend app inside another file, in this case named sampleapp.html. This has been done in lines 40-16 and a similar approach can be chosen with any other frontend framework:

2. In webpack.config.js around line 80, add a Webpack rule to allow importing CSS in the React project:

   JavaScript Copy

     module: {
       rules: [
         {
           test: /\.js$/,
           exclude: /node_modules/,
           use: {
             loader: 'babel-loader',
             options: {
               presets: [
                 ['@babel/preset-env', { targets: 'defaults' }],
                 ['@babel/preset-react', { runtime: 'automatic' }]
               ]
             }
           }
         },
         /// <---Add this rule -->
         {
           test: /\.(css)$/,
           use: ['style-loader', 'css-loader'],
         },
         /// <----->
       ]
     },

With the help of simple parameters pertaining to navigation and general settings, you will create your first “Home” navigation node and make your application responsive.

These are the Luigi navigation parameters you will use:

• pathSegment - text segment added to the URL
• label - the name of the node displayed in the navigation
• icon - a SAP icon shown next to the label
• viewUrl- the URL of your micro-frontend

1. Go to the file react-core-mf/public/luigi-config.js. This is where you can find the Luigi configuration. Copy and paste this code inside it:

   JavaScript Copy

       var defaultLocale = "en-US";
       function myTranslationProvider() {
         var dict = {
           "en-US": { PRODUCTS: "Products", ORDERHISTORY: "Order History" },
         };
         return {
           getTranslation: function (label, interpolation, locale) {
             const local = locale || Luigi.i18n().getCurrentLocale() || defaultLocale
             var translations = dict[local] || dict[defaultLocale];
             return (translations && translations[label]) || label;
           },
         };
       }
   
       Luigi.setConfig({
         navigation: {
           nodes: () => [
             {
               pathSegment: "home",
               label: "Home",
               icon: "home",
               viewUrl: "/sampleapp.html#/microfrontend/home",
             },
           ],
         },
         settings: {
           header: { title: "Luigi React App"},
           responsiveNavigation: "simpleMobileOnly",
           customTranslationImplementation: myTranslationProvider,
         },
         lifecycleHooks: {
           luigiAfterInit: () => {
             Luigi.i18n().setCurrentLocale(defaultLocale);
           },
         },
         communication: {
           customMessagesListeners: {
             "set-language": (msg) => {
               Luigi.i18n().setCurrentLocale(msg.locale);
             },
           },
         },
       });

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In this step, you will make changes to the entry point index.js for the React app. You will create a new view called home.js in react-core-mf/src/views, configure the router for this view, and import the Luigi Client. You will also create a file called language.js which will be useful for the next tutorials dealing with localization.

1. Open react-core-mf/src/index.js and change its content to:

   JavaScript Copy

   import React, { useState, useEffect } from 'react';
   import { createRoot } from 'react-dom/client';
   import { HashRouter as Router, Routes, Route } from 'react-router-dom';
   import Home from './views/home.js';
   import { dict } from './language.js';
   import { addInitListener, addContextUpdateListener, removeContextUpdateListener, removeInitListener, uxManager} from '@luigi-project/client';
   import { ThemeProvider } from "@ui5/webcomponents-react";
   
   const container = document.getElementById('root');
   const root = createRoot(container);
   
   const App = () => {
     const [currentLocale, setCurrentLocale] = useState('en-US');
     const [initListener, setInitListener] = useState(null);
     const [contextUpdateListener, setContextUpdateListener] = useState(null);
   
     useEffect(() => {
       const updateCurrentLanguage = () => {
         setCurrentLocale(uxManager().getCurrentLocale())
       }
   
       setInitListener(
         addInitListener(() => {
           console.log("Luigi Client initialized.");
           // update current language upon Luigi Client initialization
           updateCurrentLanguage();
         })
       );
   
       setContextUpdateListener(
         addContextUpdateListener(() => {
           // update current language upon Luigi Client context update event
           updateCurrentLanguage();
         })
       );
   
       return function cleanup() {
         removeContextUpdateListener(contextUpdateListener);
         removeInitListener(initListener);
       };
     }, []);
   
     return (
       <ThemeProvider>
         <React.StrictMode>
           <Router basename="microfrontend">
             <Routes>
               <Route path="/home" element={<Home localeDict={dict[currentLocale]} currentLocale={currentLocale} />} />
             </Routes>
           </Router>
         </React.StrictMode>
       </ThemeProvider>
     );
   };
   
   root.render(<App />);

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2. Next, go to the react-core-mf/src/views directory created in step 6 of the previous tutorial. Find the file called home.js and paste the following code into it:

```JavaScript
import React, { useState, useEffect } from 'react';
import "fundamental-styles/dist/fundamental-styles.css";
import { addInitListener, addContextUpdateListener, removeContextUpdateListener, removeInitListener, sendCustomMessage } from "@luigi-project/client";
import { Grid, Panel, Select, Option } from "@ui5/webcomponents-react";

const Home = (props) => {
  const [options] = useState([{ key: 'en-US', text: 'en-US' }]);

  function onChangeValue(event) {
    sendCustomMessage({
      id: "set-language",
      locale: event.detail.selectedOption.innerText,
    });
  }

  return (
    <Grid position="Center" defaultIndent="XL1 L1 M1 S1" defaultSpan="XL10 L10 M10 S10">
      <Panel headerText={props.localeDict.WELCOME_LUIGI} headerLevel="H3">
        <Select onChange={onChangeValue}>
          {options.map((language) => (
            <Option key={language.key}>{language.text}</Option>
          ))}
        </Select>
      </Panel>
    </Grid>
  );
};

export default Home;
```

3. Create a new file in react-core-mf/src called language.js with the following content:

   JavaScript Copy

   export const dict = {
     "en-US": {
       ITEMS: "Products",
       STOCKS: "Stocks",
       SELECTLANGUAGE: "Please select a language",
       PRICE: "Price",
       WELCOME_LUIGI: "Welcome to Luigi - a micro-frontend framework",
       DESCRIPTION: "Description",
       PRODUCTADDED: "Product has been added to cart",
       AVAILABLE: "Available",
       AVAILABLEQUANT: "Available quantity: ",
       ADDTOCART: "Add to cart",
       BACK: "Back",
       OUTOFSTOCK: "Out of stock",
     },
   };

In this step, you will add a navigation node in Luigi for the “Products” micro-frontend.

1. Open react-core-mf/public/luigi-config.js

2. Add a new “Products” node to your navigation:

   JavaScript Copy

   navigation: {
       nodes: () => [
         {
           pathSegment: "home",
           label: "Home",
           icon: "home",
           viewUrl: "/sampleapp.html#/microfrontend/home",
           //<---Add the section below to the config file--->
           children: [
             {
               pathSegment: "products",
               label: "Products",
               icon: "product",
               viewUrl: "/sampleapp.html#/microfrontend/products",
             }
           ],
           // <------>
         },
       ],
     },

3. Next, rename the file sample1.js in react-core-mf/src/views to products.js and paste following code into it:

   JavaScript Copy

   import React, { useEffect, useState } from 'react';
   import "../../node_modules/fundamental-styles/dist/fundamental-styles.css";
   import "@ui5/webcomponents-icons/dist/AllIcons.js";
   import { Grid, List, ListItemStandard } from "@ui5/webcomponents-react";
   import { linkManager } from "@luigi-project/client";
   import { ProductCollection } from "../assets/products.js";
   
   const Products = (props) => {
     const [listItems, setListItems] = useState([]);
   
     useEffect(() => {
       const tempList = [];
       ProductCollection.forEach((product) => {
         tempList.push(
           <ListItemStandard id={product.id} key={product.id} additionalText={product.price + " " + product.currencyCode} additionalTextState="Information" description={product.description} icon={product.icon} type="Active" onItemClick={() => handleItemClick(product.id)}>
         {product.name}
       </ListItemStandard>
         );
         setListItems(tempList);
       });
     }, [])
   
     // navigates to productDetail microfrontend through Luigi Client linkManager API
     function handleItemClick(event) {
       linkManager().withParams({ root: "products" });
       linkManager().navigate(
         "/home/products/" + event.detail.item.id.toString()
       );
     };
   
     return (
       <Grid position="Center" defaultIndent="XL1 L1 M1 S1" defaultSpan="XL10 L10 M10 S10">
         <List headerText={props.localeDict.ITEMS + ": " + ProductCollection.length} onItemClick={handleItemClick}>
           {listItems}
         </List>
       </Grid>
     );
   };
   export default Products;

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4. Add the routing module to the index.js by adding the following lines to the file:

   JavaScript Copy

   //<---Around line 8, paste this line: --->:
   import Products from "./views/products.js";
   //<------>
   ...
   <Router basename="microfrontend">
     <Routes>
       <Route path="/home" render={(props) => <Home {...props} localeDict={dict[this.state.currentLocale]} currentLocale={this.state.currentLocale} />} />
       //<---Around line 45, paste this line: --->
       <Route path="/products" element={<Products localeDict={dict[currentLocale]} />} />
       //<------>
     </Routes>
   </Router>

In this step, you will add the ProductDetail view to the app. You will be able to show details for each product via a Luigi dynamic parameter, in this case named :id.

1. In react-core-mf/public/luigi-config.js add a child node :id to the products node:

```JavaScript
      children: [
                  {
                      pathSegment: "products",
                      label: "Products",
                      icon: "product",
                      viewUrl: "/sampleapp.html#/microfrontend/products",
                      //<---Paste the section below to your config:--->
                      keepSelectedForChildren: true,
                      children: [{
                          pathSegment: ':id',
                          viewUrl: '/sampleapp.html#/microfrontend/productDetail/:id',
                          context: { id: ':id' }
                      }]
                      //<------>
                  },
```

2. Next, create a new file in react-core-mf/src/views named productDetail.js and paste following content into it:

   JavaScript Copy

       import React, { useEffect, useState, useRef } from 'react';
       import "../../node_modules/fundamental-styles/dist/fundamental-styles.css";
       import "@ui5/webcomponents-icons/dist/AllIcons.js";
       import {
           Grid, ObjectPage, Label, DynamicPageHeader, DynamicPageTitle, ObjectStatus, FlexBox, Button, Toast, ObjectPageSection, FormItem, Form, Text, Bar
       } from "@ui5/webcomponents-react";
       import { linkManager, getContext } from "@luigi-project/client";
       import { ProductCollection } from "../assets/products.js";
   
       const ProductDetail = (props) => {
           const [currentProduct, setCurrentProduct] = useState({});
           const [availability, setAvailability] = useState({
               state: "Warning",
               text: props.localeDict.OUTOFSTOCK
           });
           const toast = useRef(null);
   
           useEffect(() => {
               setProductAndAvailability();
           }, []);
   
           function setProductAndAvailability() {
               // get id from Luigi Client getContext API
               const id = getContext().id;
   
               let product = ProductCollection.find(
                   (product) => product.id.toString() === id
               ) || ProductCollection[0]
   
               setCurrentProduct(product);
               currentProduct.stock ? setAvailability({ state: "Success", text: props.localeDict.AVAILABLE }) : ""
           }
   
           // Use Luigi Client linkManager API to navigate to the previous microfrontend
           function navBack() {
               // checks if there is a previous view in history
               if (linkManager().hasBack()) {
                   // navigates to the previously opened microfrontend
                   linkManager().goBack();
               } else {
                   // navigates to the products page directly
                   linkManager().navigate("/home/products");
               }
           };
   
           return (
               <Grid position="Center" defaultIndent="XL1 L1 M1 S1" defaultSpan="XL10 L10 M10 S10">
                   <ObjectPage
                       headerContent={
                           <DynamicPageHeader>
                               <FlexBox alignItems="Center" wrap="Wrap">
                                   <FlexBox direction="Column" style={{ padding: "10px" }}>
                                       <Label>
                                           {props.localeDict.AVAILABLEQUANT + currentProduct.stock}
                                       </Label>
                                   </FlexBox>
                               </FlexBox>
                           </DynamicPageHeader>
                       }
                       footer={
                           <Bar design="FloatingFooter"
                               endContent={
                                   <>
                                       <Button design="Emphasized" onClick={() => { toast.current.show() }}>
                                           {props.localeDict.ADDTOCART}
                                       </Button>
                                       <Button design="Default" onClick={navBack}>
                                           {props.localeDict.BACK}
                                       </Button>
                                   </>
                               }
                           />
                       }
                       headerContentPinnable
                       headerTitle={
                           <DynamicPageTitle
                               actions={
                                   <>
                                       <Toast ref={toast}>
                                           {props.localeDict.PRODUCTADDED}
                                       </Toast>
                                       <Button design="Emphasized" onClick={() => { toast.current.show() }}>
                                           {props.localeDict.ADDTOCART}
                                       </Button>
                                       <Button onClick={navBack}>
                                           {props.localeDict.BACK}
                                       </Button>
                                   </>
                               }
                               header={currentProduct.name}
                           >
                               <ObjectStatus state={availability.state}>
                                   {availability.text}
                               </ObjectStatus>
                           </DynamicPageTitle>
                       }
                       onSelectedSectionChange={function noRefCheck() { }}
                       selectedSectionId="details"
                       showHideHeaderButton
                       style={{
                           height: "700px",
                       }}
                   >
                       <ObjectPageSection aria-label="Details" id="details" titleText="Details">
                           <Form columnsL={2} columnsM={2} columnsXL={3} labelSpanL={1} labelSpanM={1} labelSpanXL={1}>
                               <FormItem label="Name">
                                   <Text>{currentProduct.name}</Text>
                               </FormItem>
                               <FormItem label={props.localeDict.DESCRIPTION}>
                                   <Text>{currentProduct.description}</Text>
                               </FormItem>
                               <FormItem label={props.localeDict.PRICE}>
                                   <Text>
                                       {currentProduct.price + " " + currentProduct.currencyCode}
                                   </Text>
                               </FormItem>
                           </Form>
                       </ObjectPageSection>
                   </ObjectPage>
               </Grid>
           );
       };
   
       export default ProductDetail;

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3. Add the route configuration to the index.js by pasting below code into it:

   JavaScript Copy

       //<---Around line 9, paste this line:--->
       import ProductDetail from './views/productDetail';
       //<------>
      ...
       <Router basename="microfrontend">
         <Routes>
           <Route path="/home" render={(props) => <Home {...props} localeDict={dict[this.state.currentLocale]} currentLocale={this.state.currentLocale} />} />
           <Route path="/products" render={(props) => <Products {...props} localeDict={dict[this.state.currentLocale]} />} />
           //<---Around line 50, paste this line:--->
           <Route path="/productDetail/:id" element={<ProductDetail localeDict={dict[currentLocale]} />} />  
           //<------>    
         </Routes>
       </Router>

In this step, you can check if your core app is configured correctly so far by running it locally.

1. Open a terminal/command prompt window. Navigate to the react-core-mf folder.

2. Input npm start. Your application should be up and running at http://localhost:3000/. You should be able to see the homepage and “Products” view. You can also navigate toward the ProductDetail view via “Products”.