Tutorial: Product Highlights

You will build an illustrative Product Highlights extension in this tutorial in Node+React technology stack. You'll end up creating a working extension that would enable sellers to create highlights for required products and display the price drop tag under the price if it is altered recently.

tip

Before starting with this tutorial, make sure you have created extension using create extension guide.

Tutorial is divided into following sections

What you will learn

How to call Fynd Platform SDK methods
Build Extension UI using the Nitrozen design system
Create script tag binding to inject script tag in storefront to render extension UI elements within storefront theme
Configure Webhooks for listening to required events

Download the Product Highlight example extension

To view the complete code used for the Product Highlight example extension, you can download the source code from Github. To learn about the code step-by-step, we recommend you to follow this tutorial series.

Adding DB Configuration

Step 1: Populate test products in your development account

note

If logging in the previous step has been completed, there is no need to log in again. This step can be skipped.

fdk login

Verify if you are logged in or not by running the following command:

fdk user

Run the following command and provide company id of required development account to populate test products in it.

fdk populate

Step 2: Provide MongoDB configuration

Add port and MongoDB local URL in /.env file

MONGODB_URI="mongodb://localhost:27017/productHighlights"
PORT=8080

Add MongoDB URL in /app/config.js file

mongodb: {
    uri: {
      doc: "Mongodb uri",
      default: "",
      env: 'MONGODB_URI'
    }
  },

Step 3: Preview the changes

Preview the changes using these steps

Building the extension home page

In this section, you'll use Node.js, React, MongoDB, and Nitrozen components to build your Extension home page.

This section consists of three steps:

Create schema for saving product and its highlights using Mongoose library.
Make changes in the Extension backend.
Add additional components to the Home page of the Extension Frontend.

Step 1: Create MongoDB schema

The app needs a database to store the Product details so that merchants can view and edit the saved product highlights.

The database collection includes the product highlights, as well as the basic details about the product such as name, product brand, product slug, and product item code.

Install the mongoose package using the following command
```
npm i mongoose
```

Create new /app/db/mongo.js file and add the following code to the file

const config = require('../config');
const mongoose = require('mongoose');

// mongodb connection
mongoose.connect(config.mongodb.uri);

const ProductSchema = new mongoose.Schema({
  name: {
    type: String,
  },
  image: {
    type: String
  },
  brand_name: {
    type: String
  },
  category_slug: {
    type: String
  },
  highlights: {
    type: [String]
  },
  price: {
    type: Object
  },
  enablePriceDrop: {
    type: Boolean,
    default: false
  }
})

const ProductHighlightSchema = new mongoose.Schema({
  company_id:  {
    type: String,
  },
  application_id: {
    type: String,
  },
  product_item_code: {
    type: Number,
    unique: true,
    index: true
  },
  product_slug: {
    type: String,
    unique: true,
    index: true
  },
  product: {
    type: ProductSchema
  },
  is_active: {
    type: Boolean,
    default: false
  }
})

const ProductHighlightRecord = mongoose.model("productHighlight", ProductHighlightSchema);

module.exports = { ProductHighlightRecord }

Step 2: Update the backend API

Change the name of /app/routes/v1.router.js file to /app/routes/product.router.js and make changes to the GET /applications API

const { ProductHighlightRecord } = require('../db/mongo')

// Get applications list
router.get('/applications', async function view(req, res, next) {
    try {
        const {
            platformClient
        } = req;
        const companyId = req.fdkSession.company_id;

        let applications = await platformClient.configuration.getApplications({
            pageSize: 1000,
            q: JSON.stringify({"is_active": true})
        })

        let activeApplicationSet = new Set();
        let productSchema = await ProductHighlightRecord.find({company_id: companyId, is_active: true}, {application_id: 1});
        for (let index = 0; index < productSchema.length; index++) {
            activeApplicationSet.add(productSchema[index].application_id.toString());
        }
        for (let index = 0; index < applications?.items?.length; index++) {
            applications.items[index] = {
                ...applications?.items?.[index], 
                is_active: activeApplicationSet.has(applications.items[index]._id.toString()) ? true : false 
            }
        }
        return res.status(200).json(applications);

    } catch (err) {
        next(err);
    }
});

Also made the following changes to the /app/server.js file

change lines 3 and 31 from

3.    const v1Router = require("./routes/v1.router");
31.   apiRoutes.use('/v1.0', v1Router)

3.    const productRouter = require("./routes/product.router");
31.   apiRoutes.use('/v1.0', productRouter)

Step 3: Changes in the Front End

We’ll be using the Badge and Input components and SvgIcArrowNext Icon of the Nitrozen library

tip

Check out Nitrozen’s storybook for detailed documentation and usage instructions.

Open /src/views/Home.jsx
Delete the contents of the file.
Add the following code:

import React, { useState, useEffect } from "react";
import { useNavigate, useParams } from 'react-router-dom'

import "./style/home.css";
import Loader from "../components/Loader";
import { Badge, SvgIcArrowNext, Input } from "@gofynd/nitrozen-react";
import MainService from "../services/main-service";

export default function Home() {
  const [pageLoading, setPageLoading] = useState(false);
  const [applicationList, setApplicationList] = useState([]);
  const [allApplications, setAllApplications] = useState([]);

  const navigate = useNavigate();
  const { company_id } = useParams();

  useEffect(() => {
    fetchApplications();
  }, []);

  const fetchApplications = async () => {
    setPageLoading(true);
    try {
      const { data } = await MainService.getAllApplications();
      setAllApplications(data.items);
      const temp = data.items.map((ele) => {
        ele.text = ele.name;
        ele.value = ele._id;
        ele.image = ele.logo;
        ele.logo = ele.image && ele.image.secure_url;
        return ele;
      });
      setApplicationList(temp);
      setPageLoading(false);
    } catch (e) {
      setPageLoading(false);
    }
  };

  function searchApplication(event) {
    let searchText = event.target.value;
    if (!searchText) {
      setApplicationList(allApplications.map((app) => app));
    } else {
      setApplicationList(
        allApplications.filter((item) => {
          return item.name.toLowerCase().includes(searchText.toLowerCase());
        })
      );
    }
  }

  function clickOnSalesChannel(application_id) {
    navigate(`/company/${company_id}/${application_id}/product-list`)
  }

  return (
    <>
      {pageLoading ? (
        <Loader />
      ) : (
        <div className="application-container">

          <div className="saleschannel-title">Sales Channel</div>

          <div className="search-box">
            <Input
              showSearchIcon
              placeholder='search sales channels'
              disabled={ Object.keys(allApplications).length === 0 ? true : false }
              onChange={searchApplication}
            />
          </div>
          
          <div className="sales-channels-container">
            {applicationList.map((application) => {
              return (
                  <div className="app-box">

                    <div className="logo">
                      <img src={application.logo ? application.logo : "https://platform.fynd.com/public/admin/assets/pngs/fynd-store.png"} alt="logo" />
                    </div>

                    <div className="line-1">{application.name}</div>

                    <div className="line-2">{application.domain.name}</div>

                    <div className="button-and-arrow">
                      <div>
                        <Badge
                          fill
                          kind="normal"
                          state={application.is_active ? "success" : "disable"}
                          labelText={application.is_active ? "ACTIVE" : "INACTIVE"}
                          style={{
                            padding: "10px 6px"
                          }}
                        />
                      </div>

                      <div className="card-arrow">
                        <div className="card-arrow-box"
                          onClick={() => clickOnSalesChannel(application._id)}
                          >
                          <SvgIcArrowNext
                            className="arrow-next"
                          />
                        </div>
                      </div>

                    </div>

                  </div>
              );
            })}
            {applicationList.length % 3 === 2 && (
              <div className="app-box hidden"></div>
            )}
          </div>
          
        </div>
      )}
    </>
  );
}

Now, update the CSS file for the above code

Open /src/views/style/home.css
Delete the contents of the file.
Add the following code:

caution

CSS written in this file will have an impact on the entire project.

html {
  height: 100%;
  width: 100%;
  font-size: 8px;
}

body {
  margin: 0;
  font-family: Inter;
  background-color: #f8f8f8 !important;
  width: 100%;
  height: 100%;
  @media @mobile {
    -webkit-tap-highlight-color: transparent;
  }
}

.application-container {
  font-family: Inter;
  position: relative;
  box-sizing: border-box;
  background: #fff;
  border: 1px solid #f3f3f3;
  border-radius: 12px;
  padding: 24px;
  margin: 24px;
}

.saleschannel-title {
  font-weight: 700;
  font-size: 20px;
  margin-bottom: 8px;
}

.search-box {
  margin-top: 20px;
}

.sales-channels-container {
  display: grid;
  grid-template-columns: 25% 25% 25% 25%;
  grid-column-gap: 18px;
  grid-row-gap: 18px;
  margin-top: 20px;
  width: calc(100% - 54px);
}

.app-box {
  background-color: #ffffff;
  border: 1px solid #e4e5e6;
  padding: 20px;
  border-radius: 12px;
}

.app-box .logo {
  width: 48px;
  height: 48px;
}

.app-box .logo img {
  width: 100%;
  height: auto;
}

.app-box .line-1 {
  font-weight: 600;
  font-size: 16px;
  line-height: 26px;
  margin-top: 20px;
}

.app-box .line-2 {
  color: #9b9b9b;
  line-height: 22px;
  font-size: 12px;
}

.app-box + .app-box:nth-child(3n + 1) {
  margin-left: 0;
}

/* card footer elements */
.app-box .button-and-arrow {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 40px;
}

.card-arrow-box {
  border: 1px solid #2E31BE;
  border-radius: 4px;
  height: 36px;
  width: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-arrow-box:hover {
  transition-duration: 0.4s;
  background-color: #2E31BE;
  cursor: pointer;
}

.arrow-next {
  color: #2E31BE;
  width: 16px;
  height: auto;
}

.card-arrow-box:hover .arrow-next {
  transition-duration: 0.4s;
  color: #ffffff;
  cursor: pointer;
}

.hidden {
  visibility: hidden;
}

Step 4: Restart the server and refresh extension page in development account

Extension home page

Building 'Highlights Listing' page

Step 1: Create Backend APIs

Add the following code to the /app/routes/product.route.js.

// get product highlights list
router.get("/:application_id/highlight/list", async function view(req, res, next) {
    try {
        const { application_id } = req.params;
        const companyId = Number(req.fdkSession.company_id);
    
        let data = await ProductHighlightRecord.find({application_id: application_id, company_id: companyId}).exec();
        return res.status(200).json(data);
    } catch(error) {
        next(error)
    }
})

// get product highlight by product item code or slug  
router.get("/:application_id/highlight", async function view(req, res, next) {
    try {
        const { application_id } = req.params;
        let { slug, item_code } = req.query;
        const companyId = Number(req.fdkSession.company_id);
        // const companyId = 11197;
        let data;
        
        if (item_code) {
            item_code = Number(item_code)
            data = await ProductHighlightRecord.findOne({
                application_id: application_id, company_id: companyId, product_item_code: item_code
            }).exec();
        } else if (slug) {
            data = await ProductHighlightRecord.findOne({
                company_id: companyId, application_id: application_id, product_slug: slug
            })
        } else {
            return res.status(400).json({"Error": "Invalid Item code or slug in the query param"});
        }
    
        return res.status(200).json(data);
    } catch(error) {
        next(error);
    }
})

// delete product highlight by item code or slug
router.delete("/:application_id/highlight", async function view(req, res, next) {
    try {
        const { application_id } = req.params;
        const { slug } = req.query;
        const item_code = Number(req.query.item_code);
        const companyId = Number(req.fdkSession.company_id);
        let data;

        if (item_code !== "") {
            data = await ProductHighlightRecord.deleteOne({
                application_id: application_id, company_id: companyId, product_item_code: item_code
            }).exec();
        } else if (slug !== "") {
            data = await ProductHighlightRecord.deleteOne({
                company_id: companyId, application_id: application_id, product_slug: slug
            }).exec();
        } else {
            throw new Error("Invalid Item code or slug in query param");
        }

        return res.status(200).json(data);
    } catch(error) {
        next(error);
    }
})

Also, add the following endpoints to the Endpoints object in /src/service/endpoint.service.js file

GET_HIGHLIGHT_LIST(application_id) {
    return urlJoin(envVars.EXAMPLE_MAIN_URL, `api/v1.0/${application_id}/highlight/list`);
},
PRODUCT_HIGHLIGHT(application_id) {
    return urlJoin(envVars.EXAMPLE_MAIN_URL, `api/v1.0/${application_id}/highlight`);
},

Also, add the following methods to the MainService object in /src/service/main-service.js file

// product highlights
getHighlightList(application_id) {
  return axios.get(URLS.GET_HIGHLIGHT_LIST(application_id));
},
getProductHighlight(application_id, item_code="", slug="") {
  return axios.get(URLS.PRODUCT_HIGHLIGHT(application_id), {params: {item_code, slug}});
},
deleteProductHighlight(application_id, item_code="", slug="") {
  return axios.delete(URLS.PRODUCT_HIGHLIGHT(application_id), {params: {item_code, slug}});
},

Step 2: Create FrontEnd Page

In the /src/views/ directory create a new file called ProductList.jsx and add the following code to the file:

import React, { useEffect, useState, useRef } from "react";
import Loader from "../components/Loader";
import { Button, Input, ToggleButton, SvgIcEdit, SvgIcTrash, SvgIcArrowBack } from "@gofynd/nitrozen-react";
import { useParams, useNavigate } from 'react-router-dom'
import styles from './style/productList.module.css';
import MainService from "../services/main-service";

function ProductCard({productItem, onProductDelete}) {
  const [toggleState, setToggleState] = useState(productItem.is_active);
  const { company_id, application_id } = useParams();
  const dummyState = useRef(false);
  const navigate = useNavigate();

  useEffect(() => {
    if (dummyState.current) {
      (async () => {
        if (toggleState) {
          await MainService.addInjectableTag(application_id, productItem.product_item_code);
        } else {
          await MainService.deleteInjectableTag(application_id, productItem.product_item_code);
        }
      })()
    }
    dummyState.current = true;
  }, [application_id, productItem.product_item_code, toggleState])

  return (
    <>
      <div className={styles.product_card}>
        <div className={styles.card_left}>

          {/* PRODUCT LOGO */}
          <div className={styles.image_card}>
            <img className={styles.logo} src={productItem.product.image} alt="product_image" />
          </div>

          {/* PRODUCT META */}
          <div className={styles.product_metadata}>

            <div className={styles.product_metadata_header}>
              <div className={styles.header_name}>
                {productItem.product.name}
              </div>
              <div className={styles.pipe}>
                | 
              </div>
              <span className={styles.item_code}>
                Item code: {productItem.product_item_code}
              </span>
            </div>

            <div className={styles.product_metadata_brand}>
              {productItem.product.brand_name}
            </div>

            <div className={styles.product_metadata_category}>
              category: {productItem.product.category_slug}
            </div>

          </div>

        </div>

        {/* TOGGLE BUTTON */}
        <div className={styles.product_toggle_button}>
          <ToggleButton 
            id={productItem.product_item_code}
            size={"small"}
            value={toggleState}
            onToggle={async (event) => {
              setToggleState((pre) => !pre);
            }}
          />
        </div>
        
        <div className={styles.product_delete_edit}>
          {/* DELETE SVG */}
          <div>
            <SvgIcTrash
              color="#2E31BE"
              className={styles.product_delete}
              onClick={async () => {
                if (toggleState) {
                  await MainService.deleteInjectableTag(application_id, productItem.product_item_code);
                }
                await MainService.deleteProductHighlight(application_id, productItem.product_item_code);
                onProductDelete(productItem.product_item_code);
              }}
            />
          </div>

          {/* EDIT SVG */}
          <div>
            <SvgIcEdit 
              color="#2E31BE"
              className={styles.product_edit}
              onClick={() => {
                navigate(`/company/${company_id}/${application_id}/highlight/${productItem.product_item_code}`);
              }}
            />
          </div>
        </div>
      </div>
    </>
  )
}

export default function ProductList() {
  const [pageLoading, setPageLoading] = useState(false);
  const [productItems, setProductItems] = useState([]);
  const [allProductItems, setAllProductItems] = useState([]);
  const [searchTextValue, setSearchTextValue] = useState("");

  const navigate = useNavigate();
  const { company_id, application_id } = useParams();

  async function fetchProductItems() { 
    const { data } = await MainService.getHighlightList(application_id);
    setAllProductItems(data);
    setProductItems(data);
    setPageLoading(false);
  }

  function createProductHighlights() {
    navigate(`/company/${company_id}/${application_id}/highlight/create`)
  }

  function onProductDelete(product_item_code) {
    setAllProductItems((prevState) => {
      let findIndex = prevState.findIndex(product => product.product_item_code === product_item_code);
      prevState.splice(findIndex, 1);
      let newArr = [...prevState]
      return newArr;
    })
  }

  useEffect(() => {
    if (!searchTextValue) {
      setProductItems(allProductItems.map((product) => product))
    } else {
      setProductItems(
        allProductItems.filter((item) => {
          return item.product.name.toLowerCase().includes(searchTextValue.toLowerCase());
        })
      )
    }
  }, [allProductItems, searchTextValue]);

  useEffect(() => {
    setPageLoading(true);
    fetchProductItems()
  }, []); 

  return (
    <>
      { pageLoading ? (
        <Loader />
      ) : (
      
        <div className={styles.main_wrapper}>
          <div className={styles.sticky_header}>
            <div className={styles.navbar_left_section}>
              {/* BACK ARROW */}
              <div className={styles.back_arrow}>
                <SvgIcArrowBack 
                  color='#2E31BE'
                  style={{
                    width: "24px",
                    height: "auto"
                  }}
                  onClick={() => {
                    navigate(`/company/${company_id}/`);
                  }}
                />
              </div>

              {/* SEARCH INPUT */}
              <div className={styles.search_product_highlight}>
                <Input
                  showSearchIcon
                  className={styles.search_input}
                  type="text"
                  placeholder="search by product name"
                  value={searchTextValue}
                  disabled={Object.keys(allProductItems).length === 0 ? true : false }
                  onChange={(event) => {
                    setSearchTextValue(event.target.value);
                  }}
                />
              </div>
            </div>

            {/* CREATE HIGHLIGHT BUTTON */}
            <div className={styles.create_highlight_button}>
              <Button
                onClick={() => {createProductHighlights()}}
                rounded={false}
                >
                Create Product Highlight
              </Button>
            </div>

          </div>

          <div className={styles.product_listing}>
            {productItems.map((product) => (
              <ProductCard
                key={product.product_item_code} 
                productItem={product}
                onProductDelete={onProductDelete}
              />
            ))}
          </div>
        </div>

      )}
    </>
  );
}

Step 3: Add CSS for the ProductList component

In the /src/views/style/ directory create a new file called productList.module.css and add the following code to the file

.main_wrapper {
  font-family: Inter;
  position: relative;
  box-sizing: border-box;
  background: #fff;
  border: 1px solid #f3f3f3;
  border-radius: 12px;
  padding: 24px;
  margin: 24px;
}

.sticky_header {
  background-color: #ffffff;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
}

.back_arrow {
  cursor: pointer;
}

.navbar_left_section {
  display: flex;
  align-items: center;
}

/* button */
.create_highlight_button {
  margin: 12px 12px;
  max-height: 48px;
}

/* Product search */
.search_product_highlight {
  max-width: 480px;
  min-width: 480px;
  margin: 0 24px;
}

.search_input {
    height: 18px;
}

/* Product listing */
.product_listing {
  margin: 0 16px;
  padding-top: 24px;
}

.product_card {
  display: flex;
  justify-content: space-between;
  border: 1px solid #e4e5e6;
  min-height: 102px;
  padding: 16px;
  border-radius: 4px;
  margin-bottom: 16px;
  box-sizing: border-box;
  transition: box-shadow 0.3s;
}

.product_card:hover {
  box-shadow: 0px 9px 13px 0px rgba(221, 221, 221, 0.5);
}

.product_card .card_left {
  display: flex;
  flex-direction: row;
  align-items: center;
  flex: 2;
}

.product_card .image_card {
  min-height: 60px;
  min-width: 60px;
  max-height: 60px;
  max-width: 60px;
  display: flex;
  align-items: center;
  margin: 0 12px;
}

.product_card .image_card .logo {
  height: 60px;
  width: 100%;
  object-fit: cover;
  border-radius: 50%;
}

.product_metadata {
  display: flex;
  flex-direction: column;
}

.product_metadata_header {
  display: flex;
  flex-direction: row;
  align-items: center;
}

.product_metadata_header .header_name {
  line-height: 21px;
  margin-right: 10px;
  color: #41434C;
  font-weight: 600;
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

.product_metadata_header .pipe {
  line-height: 20px;
  margin-right: 10px;
  color: #9B9B9B;
  font-weight: 400;
  font-size: 12px;
  -webkit-font-smoothing: antialiased;
}

.product_metadata_header .item_code {
  line-height: 20px;
  color: #9B9B9B;
  font-weight: 400;
  font-size: 12px;
  -webkit-font-smoothing: antialiased;
}

.product_metadata_brand, .product_metadata_category {
  color: #666666;
  line-height: 21px;
  font-weight: 400;
  font-size: 12px;
  -webkit-font-smoothing: antialiased;
}

.product_toggle_button {
  flex: 0.5;
  display: flex;
  align-items: center;
  justify-content: center;
}

.product_delete_edit {
  display: flex;
  flex-direction: row;
  flex: 0.5;
  align-items: center;
  justify-content: space-evenly;
}

.product_delete, .product_edit  {
  height: 24px;
  width: auto;
  margin: 12px;
}

.product_edit:hover, .product_delete:hover {
  cursor: pointer;
}

Step 4: Create a Route for ProductList component

Using react-router to create routes for the Product List page

Add the following objects to the CreateBrowserRouter list in /src/router/index.js file

{
    path: "/company/:company_id/:application_id/product-list/",
    element: <ProductList />
},

Import ProductList component at the top of /src/router/index.js file
```
import ProductList from "../views/ProductList";
```

Step 5: Restart the extension server and refresh extension page in development account

QG1

Clicking on this arrow will redirect the user to the ProductList page

QG1

Currently we don’t have highlights created for the products, that’s why any products are not showing. In order to create product highlights we’ll need to create CreateProductHighlight page.

Building 'Create Highlight' page

Step 1: Create Backend APIs

Add the following code to the /app/routes/product.route.js

// get product list
router.get('/:application_id/products', async function view(req, res, next) {
    try {
        const { platformClient } = req;
        const { application_id } = req.params;
        const { query } = req.query;
        let response = await platformClient.application(application_id).catalog.getAppProducts({
            pageNo: 1,
            pageSize: 10,
            q: query
        })
        return res.status(200).json(response)
    } catch(error) {
        next(error);
    }
})

// update product highlights
router.post("/:application_id/product/:item_id/highlights", async function view(req, res, next) {
    try {
        const { application_id, item_id } = req.params;
        const { product_meta, highlights, enablePriceDrop } = req.body        
        const companyId = Number(req.fdkSession.company_id);

        let productHighlightRecord = await ProductHighlightRecord.findOne({
            company_id: companyId, application_id: application_id, product_item_code: item_id
        }).exec()

        if (productHighlightRecord) {
            productHighlightRecord.product.highlights = highlights;
            productHighlightRecord.product.enablePriceDrop = enablePriceDrop;
            await productHighlightRecord.save();

        } else {
            const prepareRecord = {
                company_id: companyId,
                application_id: application_id,
                product_item_code: product_meta.product_item_code,
                product_slug: product_meta.product_slug,
                product: {
                    name: product_meta.name,
                    image: product_meta.image,
                    brand_name: product_meta.brand_name,
                    category_slug: product_meta.category_slug,
                    highlights: highlights,
                    price: product_meta.price,
                    enablePriceDrop: enablePriceDrop
                },
                is_active: false
            }
            productHighlightRecord = await new ProductHighlightRecord(prepareRecord).save();
        }
        return res.status(200).json(productHighlightRecord);

    } catch(error) {
        next(error);
    }
})

Also, add the following endpoints to the Endpoints object in /src/service/endpoint.service.js file

GET_PRODUCTS(application_id) {
    return urlJoin(envVars.EXAMPLE_MAIN_URL, `api/v1.0/${application_id}/products`);
},
CREATE_PRODUCT_HIGHLIGHTS(application_id, item_id) {
    return urlJoin(envVars.EXAMPLE_MAIN_URL, `api/v1.0/${application_id}/product/${item_id}/highlights`);
},

Also, add the following methods to the MainService object in /src/service/main-service.js file

getAllProducts(application_id, query) {
    return axios.get(URLS.GET_PRODUCTS(application_id), {params: {query}});
},
createProductHighlights(application_id, item_id, data) {
    return axios.post(URLS.CREATE_PRODUCT_HIGHLIGHTS(application_id, item_id), data);
},

Step 2: Create FrontEnd page

In the /src/views/ directory create a new file called CreateHighlight.jsx

Add the following code to the file

import React, { useEffect, useState } from 'react';
import { useParams, useNavigate } from 'react-router-dom';

import { 
  Button, Dropdown, Input, Checkbox,  SvgIcConfirm, SvgIcArrowBack, SvgIcTrash
} from '@gofynd/nitrozen-react';
import MainService from '../services/main-service';
import styles from './style/createHighlight.module.css'

export default function CreateHighlight() {
  // page params
  const { company_id, application_id, item_code } = useParams();
  
  // navigation instance
  const navigate = useNavigate();

  // application product list
  const [productItems, setProductItems] = useState([]);
  const [searchText, setSearchText] = useState('');

  // highlight text input
  const [highlightInput, setHighlightInput] = useState("");

  // locally maintained highlight list
  const [highlightList, setHighlightList] = useState([]);

  // current selected dropdown value
  const [selectedDropdownProduct, setSelectedDropdownProduct] = useState({});

  // is edit page
  const [isEdit, setIsEdit] = useState(false);
  const [editProduct, setEditProduct] = useState({});

  // price drop
  const [checkboxValue, setCheckboxValue] = useState(false);

  // handle dropdown search
  useEffect(() => {
    const delayDebounceFn = setTimeout(() => {
      console.log(searchText)
      getApplicationProductList();
    }, 500)
    return () => clearTimeout(delayDebounceFn)
  }, [searchText])

  // application product list for dropdown
  const getApplicationProductList = async () => {
    if (item_code) {
      setIsEdit(true);
      const { data } = await MainService.getProductHighlight(application_id, item_code);
      setHighlightList(data?.product?.highlights);
      setCheckboxValue(data?.product?.enablePriceDrop);
      setEditProduct({
        name: data?.product?.name,
        product_slug: data?.product_slug,
        image: data?.product?.image,
        brand_name: data?.product?.brand_name,
        category_slug: data?.product?.category_slug,
        product_item_code: data?.product_item_code
      })
      
    } else {
      const { data } = await MainService.getAllProducts(application_id, searchText);
      setProductItems(data.items);
    }
  }

  // handle dropdown onChange
  const dropdownChangeHandler = async (productMeta) => {
    
    let { data } = await MainService.getProductHighlight(application_id, productMeta.product_item_code);
    if (data) {
      setHighlightList(data.product.highlights);
      setCheckboxValue(data.product.enablePriceDrop);
    } else {
      setHighlightList([]);
      setCheckboxValue(false);
    }
    setSelectedDropdownProduct(productMeta);
  }
  
  // Dropdown data
  const getSearchItems = () => {
    let prepareProductList = []
    productItems.forEach((product) => {
      let searchProduct = {}
      searchProduct.text = product?.name
      searchProduct.sub_text = product?.brand?.name
      searchProduct.value = {
        name: product?.name,
        product_slug: product?.slug,
        image: product?.images[0],
        brand_name: product?.brand?.name,
        category_slug: product?.category_slug,
        product_item_code: product?.uid,
        price: product?.price
      }
      searchProduct.logo = product?.images[0]
      prepareProductList.push(searchProduct);
    })
    return prepareProductList;
  }

  const handleSubmit = async () => {
    if (isEdit) {
      await MainService.createProductHighlights(
        application_id,
        editProduct.product_item_code,
        {
          productMeta: editProduct,
          highlights: highlightList,
          enablePriceDrop: checkboxValue
        }
      )

    } else {
      await MainService.createProductHighlights(
        application_id, 
        selectedDropdownProduct.product_item_code, 
        {
          product_meta: selectedDropdownProduct,
          highlights: highlightList,
          enablePriceDrop: checkboxValue
        }
      )
    }

    navigate(`/company/${company_id}/${application_id}/product-list/`);
  }  

  return (
    <>
      <div className={styles.main_wrapper}>

        {/* NAVBAR */}
        <div className={styles.navbar}>

          {/* NAVBAR LEFT */}
          <div className={styles.navbar_left_header}>
            <div className={styles.back_arrow}>
              <SvgIcArrowBack 
                color='#2E31BE'
                style={{
                  width: "24px",
                  height: "auto"
                }}
                onClick={() => {
                  navigate(`/company/${company_id}/${application_id}/product-list/`)
                }}
              />
            </div>
            <div className={styles.main_title}>
              {isEdit ? ("Edit") : ("Create")} Product Highlight
            </div>
          </div>

          {/* NAVBAR RIGHT */}
          <div className={styles.navbar_buttons}>
            {/* DISCARD BUTTON */}
            <div>
              <Button
                state='default'
                theme='secondary'
                // size='small'
                rounded={false}
                onClick={() => {
                  navigate(`/company/${company_id}/${application_id}/product-list/`)
                }}
                >
                Discard
              </Button>
            </div>
              
            {/* SUBMIT BUTTON */}
            <div>
              <Button
                state='default'
                theme='primary'
                // size='small'
                rounded={false}
                onClick={handleSubmit}
                >
                {isEdit ? ("Save") : ("Submit")}
              </Button>
            </div>
          </div>

        </div>
        {/* END NAVBAR */}

        <div className={styles.content_wrapper}>

          <div className={styles.highlight_detail_box}>
            <div>
              <div className={styles.highlight_detail_box_header}>Product Highlight Detail</div>
            </div>
            
            {/* PRODUCT DROPDOWN */}
            {!isEdit ? (
              <div className={styles.select_product_dropdown}>
                <Dropdown
                  placeholder="select product"
                  searchable={true}
                  items={getSearchItems()}
                  onChange={(productMeta) => {dropdownChangeHandler(productMeta);}}
                  onSearchInputChange={(e) => {setSearchText(e.text);}}
                />
              </div>
            ) : (
              <div className={styles.edit_product_title}>
                <Input 
                  type='text'
                  value={editProduct.name}
                  disabled={true}
                />
              </div>
            )}

            <div className={styles.add_highlights_header}>
              Add/Edit Highlights
            </div>
            
            {/* HIGHLIGHTS LIST */}
            <div>
              {highlightList?.map((highlight, index) => (
                <div className={styles.highlight_list}>
                  <div>
                    {highlight}
                  </div>

                  <div className={styles.highlight_list_delete}>
                    <SvgIcTrash 
                      className={styles.highlight_delete}
                      style={{
                        height: "24px",
                        width: "auto"
                      }}
                      color="#2E31BE"
                      onClick={() => {
                        setHighlightList((prevItem) => {
                          return [...prevItem.slice(0, index), ...prevItem.slice(index+1)]
                        })
                      }}
                    />
                  </div>

                </div>
              ))}
            </div>

            <div className={styles.highlight_input_ok}>
              {/* HIGHLIGHT INPUT */}
              <div className={styles.highlight_input_div}>
                <Input
                  placeholder='add highlights'
                  style={{
                    padding: "0px"
                  }}
                  max={200}
                  min={1}
                  value={highlightInput}
                  disabled={ !isEdit && Object.keys(selectedDropdownProduct).length === 0 ? true : false }
                  onChange={(e) => {setHighlightInput(e.target.value)}}
                  onKeyPress={(e) => {
                    if (e.key === 'Enter') {
                      setHighlightList([...highlightList, highlightInput])
                      setHighlightInput("")
                    }
                  }}
                />
              </div>
              {/* HIGHLIGHT OK BUTTON */}
              <div
                onClick={() => {
                  setHighlightList([...highlightList, highlightInput])
                  setHighlightInput("")
                }}
                >
                {highlightInput && (
                  <SvgIcConfirm
                    color='#2e31be'
                    style={{
                      height: "24px",
                      width: "auto",
                      cursor: "pointer"
                    }}
                  />
                )}
              </div>
            </div>

            {/* ENABLE PRICE DROP CHECKBOX */}
            <div className={styles.enable_price_drop_checkbox}>
              <Checkbox 
                labelText="Enable 'Price Drop' label whenever price is reduced in last 2 days"
                disabled={ !isEdit && Object.keys(selectedDropdownProduct).length === 0 ? true : false }
                checkboxValue={checkboxValue}
                onChange={(changedState) => {
                  setCheckboxValue(changedState);
                }}
              />
            </div>

          </div>

          <div className={styles.highlight_preview_box}>
            <div className={styles.preview_box_header}>
              Preview
            </div>
            <div className={styles.horizontal_line}></div>
            <div>
              {highlightList.length>0 && <div className={styles.highlightTitle}>Product Highlights</div>}
              <div>
                {highlightList?.map((highlight) => (
                  <div className={styles.highlightList}>{highlight}</div>
                ))}
              </div>
            </div>
          </div>

        </div>
      </div>
    </>
  )
}

Step 3: Add CSS for the CreateHighlight component

In the /src/views/style/ directory create a new file called createHighlight.module.css

Add the following code to the file

@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&display=swap');

.main_wrapper {
    font-family: Inter;
    position: relative;
    box-sizing: border-box;
    background: #fff;
    border: 1px solid #f3f3f3;
    border-radius: 12px;
    padding: 24px;
    margin: 24px;
}

.navbar {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
}

.navbar_left_header {
    display: flex;
    align-items: center;
}

.main_title {
    font-size: 22px;
    font-weight: 600;
    margin: 0 24px;
    color: #41434c;
}

.back_arrow {
    cursor: pointer;
}

.navbar_buttons {
    display: flex;
    flex-direction: row;
    align-items: center;
}

.navbar_buttons Button {
    margin: 0 16px;
}

/* content wrapper */
.content_wrapper {
    display: flex;
    flex-direction: row;
    gap: 16px;
    margin-top: 16px;
}

/* details box */
.highlight_detail_box {
    flex: 1.5;
    padding: 16px;
}

.highlight_detail_box_header {
    font-size: 16px;
    font-weight: 700;
    color: #41434c;
}

/* DROP DOWN */
.select_product_dropdown {
    margin: 12px 0;
    max-width: 50%;
}

.edit_product_title {
    margin: 12px 0;
    max-width: 50%;
}

.edit_product_title div {
    padding: 0;
    max-height: 64px;
}

.edit_product_title input {
    padding: 6px 24px;
}

.add_highlights_header {
    font-size: 16px;    
    font-weight: 400;
    line-height: 140%;
    margin-top: 24px;
    color: rgba(102, 102, 102, 0.5);
}

/* HIGHLIGHT LIST */
.highlight_list {
    display: flex;
    flex-direction: row;
    padding: 8px 16px;
    align-items: center;
    justify-content: space-between;
    gap: 12px;

    font-weight: 400;
    line-height: 140%;
    color: #4f4f4f;
    font-size: 14px;
}

.highlight_list_delete {
    padding: 0 4px;
    cursor: pointer;
}

/* HIGHLIGHT INPUT */
.highlight_input_ok {
    margin: 12px 0;
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 24px;
}

.highlight_input_div {
    min-width: 360px;
    max-width: 512px;
    width: -webkit-fill-available;
}

.highlight_input_div input {
    font-size: 16px;
    padding: 0px 16px;
}

.highlight_input_div input::placeholder {
    font-size: 16px;
}

/* preview box */
.highlight_preview_box {
    margin-top: 12px;
    padding: 16px;
    flex: 1;
    border: 1px solid #e4e5e6;
    border-radius: 4px;
}

.preview_box_header {
    font-size: 16px;
    font-weight: 700;
    color: #41434c;
}

.horizontal_line {
    border: 1px solid #ccc;
}

.highlightTitle {
    font-size: 18px;
    font-weight: 700;
    color: #000;
    padding: 16px 0 0 0;
    font-family: 'Montserrat', sans-serif;
}

.highlightList {
    font-size: 16px;
    font-weight: 400;
    color: #000;
    padding: 10px 0;
    font-family: 'Montserrat', sans-serif;
}

.enable_price_drop_checkbox {
    margin: 24px 0px;
}

.enable_price_drop_checkbox label {
    justify-content: flex-start;
}

Step 4: Create a Route for CreateHighlight component

Add the following objects to the CreateBrowserRouter list in /src/router/index.js file

{
    path: "/company/:company_id/:application_id/highlight/create",
    element: <CreateHighlight />
},
{
    path: "/company/:company_id/:application_id/highlight/:item_code",
    element: <CreateHighlight />
}

Import ProductList component at the top of /src/router/index.js file
```
import CreateHighlight from "../views/CreateHighlight";
```
note
We are using the same component CreateHighlight for creating new product highlights and updating existing product highlights.

Step 5: Restart the extension server and refresh extension page in development account

Clicking on this arrow button redirect the user to the CreateHighlight page

Now you can create Highlights for products by following the below steps:

Select any product from the dropdown.
Add highlights using an input text box.
After adding all the highlights click on Submit.

submit product highlight

It’ll redirect to the ProductList page

product listing page

We’ve completed the UI flow of the Extension. Now in the next step, we will add functionality to show highlights on the Product description page of the store website.

Injecting Javascript into the storefront theme

We’ll need to inject Javascript into the theme to show the product highlights and price drop label. Fynd Platform Theme engine is built with Vue2, that’s why we will have to create an Injectable script in Vue itself.

info

Fynd Platform now supports React themes as well. For more information on theme development, please refer to the documentation.

Step 1: Create Binding in Extension

Visit Fynd Partners.
Click on Manage and Select your organization.
Click on Extensions from the left Menu.
Select your Extension.
Click on three dots and then select Bindings as shown in the below image.

click on bindings

Click on Add Template and fill in the data as shown in the below image.

create binding for product highlights

Repeat Step 6 for the Price Drop Tag also.

create binding for price drop

binding list page

Now in the next step, we’ll create Vue components and inject them using these bindings.

Step 2: Setup Vue project

Install vue-cli npm package using the following command
```
npm i -g @vue/cli
```
Create new directory binding inside your project root directory using the following command
```
mkdir bindings
cd bindings
```
Create Vue project
```
vue create .
```
note
Choose Yes for the prompt “Generate project in the current directory?” and select Vue2 for the prompt “Please pick a preset:”

Open /bindings/vue.config.js file and replace the code with the following code

module.exports = {
  pages: {
    index: {
      // entry for the page
      entry: process.env.NODE_ENV == "development" ? 'src/dev.js' : 'src/main.js'
    },
  },
  devServer: {
    disableHostCheck: true
  }
}

Install axios and url-join package inside /bindings/ directory using the following commands
```
npm i axios
npm i url-join
```

In the /binding/ directory, open the /package.json file and replace the following line

"build": "vue-cli-service build",

with

"build": "vue-cli-service build --target lib src/main.js --name product-highlights",

Delete unnecessary files such as README.md and jsconfig.json files from the /bindings/ directory
Delete all the files and folders from the /bindings/src directory

In the /bindings/src/ directory, create a new file called dev.js and add the following code to the file:

import App from './App.vue';
import Vue from 'vue';

new Vue({
  render: h => h(App)
}).$mount('#app')

In the /bindings/src/ directory, create a new file called main.js and add the following code to the file:

import Highlights from './Highlights.vue'
import PriceDrop from './PriceDrop.vue'

window.FPI.extension.register("#product-highlights", {
  mounted(element) {
    window.FPI.extension.mountApp({
      element, 
      component: Highlights
    });
  }
})

window.FPI.extension.register("#product-price-drop", {
  mounted(element) {
    window.FPI.extension.mountApp({
      element,
      component: PriceDrop
    })
  }
})

Step 3: Create Vue components

In the /bindings/src/ directory, create a new file called Highlights.vue and add the following code to the file:

<template>
  <div class="product-highlights">
    <div v-if="highlightsData"> 
      <div class="highlightTitle">Product Highlights</div>
      <div
        v-for="(highlight, index) in highlightsData"
        :key="index"
        >
        <div class="highlightList">{{highlight}}</div>
      </div>
    </div>
  </div>
</template>

<script>
import axios from 'axios';
import urlJoin from "url-join";

export default {
  name: "ProductHighlights",
  
  data() {
    return {
      highlightsData: null
    };
  },

  async mounted() {
    const baseURL = window.location.origin;
    const product_slug = this.$route.params.slug;

    
    let { data } = await axios.get(
      urlJoin(baseURL, 'ext/producthighlights/highlight'), 
      { params: {slug: product_slug} }
    );
    
    if (data && data.is_active && data.product && data.product.highlights && data.product.highlights.length) {
      this.highlightsData = data.product.highlights
    }
  },
}
</script>

<style>
.highlightTitle {
  font-size: 14px;
  font-weight: 700;
  color: #000000;
  padding: 32px 0 6px 0;
}

.highlightList {
  font-size: 14px;
  font-weight: 400;
  color: #000000;
  padding: 8px 0;
}
</style>

Download drop-price-tag.svg file from GitHub and add it into the /bindings/assets/ directory. Here is the link to SVG : Click Here

In the /bindings/src/ directory, create a new file called PriceDrop.vue and add the following code to the file:

<template>
  <div>
    <div v-if="showPriceDrop">
      <img src="../assets/drop-price-tag.svg" alt="price-drop-png" />
    </div>
  </div>
</template>

<script>
import axios from "axios";
import urlJoin from "url-join";
export default {
  name: 'PriceDrop',

  data() {
    return {
      showPriceDrop: false
    }
  },

  async mounted() {
    const baseURL = window.location.origin;
    const product_slug = this.$route.params.slug;

    let { data } = await axios.get(
      urlJoin(baseURL, 'ext/producthighlights/price-drop'), 
      { params: {slug: product_slug} }
    );

    if (data && data.showPriceDrop) {
      this.showPriceDrop = true;
    }
  }

}
</script>

<style scoped>
img {
  height: 48px;
  width: auto;
}
</style>

Build the project using the following command inside /bindings/ directory.
```
npm run build
```

Step 4: Write logic for script injection

In the /app/ directory, open the /server.js file and replace following line
```
app.use(express.static(path.resolve(__dirname, "../build/")));
```
with
```
app.use(express.static(path.resolve(__dirname, "../build/")));
app.use('/bindings/product-highlights', express.static(path.join(__dirname, '../bindings/dist')))
```
with these we are serving min.js files which we have created by building the bindings bundle. Now these min.js files can be accessed using Extension base URL.

To maintain the record of the Proxy we will create one MongoDB schema. for that open the /app/db/mongo.js file and add the following code

const ProxySchema = new mongoose.Schema({
  company_id: {
    type: String,
    required: true
  },
  application_id: {
    type: String,
    required: true
  },
  attached_path: {
    type: String
  },
  proxy_url:{
    type: String
  },
})
const ProxyRecord = mongoose.model("Proxy", ProxySchema);

add also export newly created ProxyRecord at end of the file

module.exports = { ProductHighlightRecord, ProxyRecord }

For adding a Proxy we’ll require unique string which will be passed as a parameter to the addProxyPath method.
Add the following line at the end of .env file at project directory
```
PROXY_ATTACH_PATH="producthighlights"
```

Add proxy_attach_path to /app/config.js file

proxy_attach_path: {
  doc: "Proxy attach path",
  default: '',
  env: "PROXY_ATTACH_PATH"
},

In the /app/routes/ directory, create a new file called script.router.js and add the following code to the file:

const express = require('express');
const router = express.Router();
const config = require('../config');
const { ProductHighlightRecord, ProxyRecord } = require('../db/mongo')

function getTagSchema(application_id) {
  return [
    {
      "name": "Product Highlights injection script",
      "sub_type": "external",
      "type": "js",
      "position": "body-bottom",
      "url": `${config.extension.base_url}/bindings/product-highlights/product-highlights.umd.js`,
      "attributes": {
        "id": application_id
      }
    },
    {
      "name": "Product Highlights injection css",
      "sub_type": "external",
      "type": "css",
      "position": "head",
      "url": `${config.extension.base_url}/bindings/product-highlights/product-highlights.css`,
      "attributes": {
      }
    }
  ]
}

router.post("/:application_id/tag/:item_code", async function view(req, res, next) {
  try {
    const { platformClient } = req;
    const { application_id, item_code } = req.params;
    const companyId = Number(req.fdkSession.company_id);

    let response;
    let data = await ProductHighlightRecord.findOne({
      application_id: application_id, company_id: companyId, product_item_code: item_code
    }).exec()

    if (data) {
      data.is_active = true;
      await data.save();

      // add proxy
      let proxyCount = await ProxyRecord.find({company_id: companyId, application_id: application_id}).count();
      if (proxyCount < 1) {
        await platformClient.application(application_id).partner.addProxyPath({
          extensionId: config.extension.api_key, 
          body: {
            attached_path: config.proxy_attach_path, 
            proxy_url: `${config.extension.base_url}/app/proxy`
          }
        })
        let prepareProxy = {
          company_id: companyId,
          application_id: application_id,
          attached_path: config.proxy_attach_path,
          proxy_url: `${config.extension.base_url}/app/proxy`
        }
        await new ProxyRecord(prepareProxy).save();
      }
      
      response = await platformClient.application(application_id).content.addInjectableTag({
        body: {tags: getTagSchema(application_id)}
      })
    } else {
      throw new Error(`Invalid item code: ${item_code}`)
    }

    return res.status(200).json(response);
  } catch(err) {
    next(err);
  }
})

router.delete("/:application_id/tag/:item_code", async function view(req, res, next) {
  try {
    const { platformClient } = req;
    const { application_id, item_code } = req.params;
    const companyId = Number(req.fdkSession.company_id);

    let data = await ProductHighlightRecord.findOne({
      application_id: application_id, company_id: companyId, product_item_code: item_code
    }).exec()

    if (data) {
      data.is_active = false;
      await data.save();

      let activeCount = await ProductHighlightRecord.find({
        application_id: application_id, company_id: companyId, is_active: true
      }).count();

      if (activeCount < 1) {
        let proxy = await ProxyRecord.deleteOne({company_id: companyId, application_id: application_id}).exec();
        if (proxy) {
          await platformClient.application(application_id).partner.removeProxyPath({
            extensionId: config.extension.api_key, attachedPath: config.proxy_attach_path
          })
        }
        await platformClient.application(application_id).content.deleteAllInjectableTags();
      }

    } else {
      return res.status(400).json({"Error": `Invalid item code: ${item_code}`});
    }

    return res.status(204).json({"data": "success"});
  } catch(err) {
    next(err);
  }
})

module.exports = router;

In this script.router.js file we have created APIs which will be called when activating or deactivating toggle button on the product list page.

This APIs will create and destroy the proxy by calling to addProxyPath and removeProxyPath methods of the platformClient respectively.

We will use this proxy to call our Extension endpoints from the store front website which will prevent the CORS error thrown by the browser.

tip

For API documentation on addProxyPath and removeProxyPath , please refer to these links.

tip

To learn more about how proxy URLs work, visit this link.

Also, add the following endpoints to the Endpoints object in /src/service/endpoint.service.js file.

INJECTABLE_TAG(application_id, item_code) {
    return urlJoin(envVars.EXAMPLE_MAIN_URL, `api/v1.0/${application_id}/tag/${item_code}`);
}

Also, add the following methods to the MainService object in /src/service/main-service.js file.

// script inject
addInjectableTag(application_id, item_code) {
    return axios.post(URLS.INJECTABLE_TAG(application_id, item_code));
},
deleteInjectableTag(application_id, item_code) {
    return axios.delete(URLS.INJECTABLE_TAG(application_id, item_code));
}

Now we’ll develop APIs for the application. Both the following APIs will be called from the Product Description Page of the store front. One of the API will return the highlights of the product and the other one will return the boolean value on whether to show Price Drop tag or not.

Before that we will need one MongoDB schema to store the data about whether product’s price has dropped in last 2 days or not.

Open /app/db/mongo.js file and add the following code

const PriceDropSchema = new mongoose.Schema({
  product_slug: {
    type: String,
    require: true,
    index: true,
    unique: true
  },
  updatedAt: {
    type: Date,
    default: Date.now
  }
})
PriceDropSchema.pre('save', function(next) {
  let now = Date.now();
  this.updatedAt = now;
  next();
})
PriceDropSchema.path('updatedAt').index({expires: 172800}) // 172800 seconds == 2 days
const PriceDropRecord = mongoose.model("PriceDrop", PriceDropSchema);

Add also export newley created PriceDropSchema at end of file

module.exports = { ProductHighlightRecord, ProxyRecord, PriceDropRecord }

In the /app/routes/ directory, create a new file called app.router.jsand add the following code to the file:

const express = require('express');
const { ProductHighlightRecord, PriceDropRecord } = require('../db/mongo');
const router = express.Router();

router.get("/highlight", async function view(req, res, next) {
  try {
    const application_id = req.application._id;
    const { slug } = req.query;

    let data = await ProductHighlightRecord.findOne({
      application_id: application_id, product_slug: slug
    })

    if (data) {
      return res.status(200).json(data);
    } else {
      return res.status(404).json({message: "Not found!"});
    }
  } catch(err) {
    next(err)
  }
})

router.get("/price-drop", async function view(req, res, next) {
  try {
    const application_id = req.application._id;
    const { slug } = req.query;

    let data = await PriceDropRecord.find({product_slug: slug}).exec();
    if (data) {
      let productData = await ProductHighlightRecord.findOne({
        application_id: application_id, product_slug: slug
      })
      if (productData.is_active) {
        return res.status(200).json({showPriceDrop: productData.product.enablePriceDrop});
      } else {
        return res.status(200).json({showPriceDrop: false});
      }
    } else {
      return res.status(200).json({showPriceDrop: false});
    }

  } catch(err) {
    next(err);
  }
})

module.exports = router;

Open /app/server.js file and replace with following code:

const express = require('express');
const cookieParser = require('cookie-parser');
const bodyParser = require('body-parser');
const path = require("path");
const healthzRouter = require("./routes/healthz.router");
const productRouter = require("./routes/product.router");
const scriptRouter = require("./routes/script.router");
const appRouter = require("./routes/app.router");
const fdkExtension = require("./fdk");
const app = express();
const config = require("./config");
app.use(cookieParser("ext.session"));
app.use(bodyParser.json({
    limit: '2mb'
}));
app.get('/env.js', (req, res) => {
    const commonEnvs = {
      base_url: config.extension.base_url
    }
    res.type('application/javascript');
    res.send(
      `window.env = ${JSON.stringify(
        commonEnvs,
        null,
        4
      )}`
    );
});
app.use("/", healthzRouter);
app.use(express.static(path.resolve(__dirname, "../build/")));
app.use('/bindings/product-highlights', express.static(path.join(__dirname, '../bindings/dist')))
app.use("/", fdkExtension.fdkHandler);

// platform routes
const apiRoutes = fdkExtension.apiRoutes;
apiRoutes.use('/v1.0', productRouter);
apiRoutes.use('/v1.0', scriptRouter);
app.use('/api', apiRoutes);

// application routes
const applicationProxyRoutes = fdkExtension.applicationProxyRoutes
applicationProxyRoutes.use("/proxy", appRouter);
app.use('/app', applicationProxyRoutes);

app.get('/company/:company_id', (req, res) => {
  res.sendFile(path.resolve(__dirname, "../build/index.html"))
})

app.get('*', (req, res) => {
  res.contentType('text/html');
  res.sendFile(path.resolve(__dirname, '../build/index.html'))
});

// webhook handler
app.post('/ext/product-highlight-webhook', async function(req, res) {
  try {
    console.log("1");
    await fdkExtension.webhookRegistry.processWebhook(req);
    return res.status(200).json({"success": true});
  } catch(err) {
    console.log(2);
    return res.status(500).json({"success": false});
  }
})

module.exports = app;

Step 5: Restart the extension server and refresh extension page in development account

caution

When the tunnel is restarted, the extension's local development base URL also changes. Consequently, any existing proxy for a sales channel won't function properly. To address this, it's advisable to remove the old proxy associated with the previous tunnel URL and add the new tunnel URL as a proxy.

The simplest approach is to uninstall the extension from the development company and then reinstall it.

As shown on below image, when clicking on Toggle button, API call is made to Extension backend. Which will inject the script into store front theme.

click on toggle button

But highlights won’t be visible on the product description page of the product for which we have activated highlights. To show the highlights user will have to configure extension binding in their theme.

Visit platform.fynd.com
Select the sales channel
Appearance > Themes
Edit the current active theme

edit current active theme

Select Product Description from top menu and select any product
Select Page tab of Sections and Scroll down for Extension Positions
Add Product Highlight Extension at Below Price Component position and Below Product Info position as shown in below image
Click on Save

Now Visit PDP page of the product for which you have activated highlights. You should be able to get see the highlight below Product Info.

product highlight in sales channel

Configuring Webhook

Add Webhook config Object in your /app/fdk/index.js file

const { setupFdk } = require("fdk-extension-javascript/express");
const { RedisStorage } = require("fdk-extension-javascript/express/storage");
const config =  require("../config");
const { appRedis } = require("./../common/redis.init");
const { productPriceUpdateHandler } = require('../webhook')

let fdkExtension = setupFdk({
    api_key: config.extension.api_key,
    api_secret: config.extension.api_secret,
    base_url: config.extension.base_url,
    callbacks: {
        auth: async (req) => {
            // Write your code here to return initial launch url after auth process complete
            return `${req.extension.base_url}/company/${req.query['company_id']}`;
        },
        
        uninstall: async (req) => {
            // Write your code here to cleanup data related to extension
            // If task is time taking then process it async on other process.
        }
    },
    // debug: true,
    storage: new RedisStorage(appRedis,"product-highlights-ext"), // add your prefix
    access_mode: "offline",
    cluster: config.extension.fp_api_server,
    webhook_config: {
        api_path: "/ext/product-highlight-webhook",
        notification_email: "[email protected]",
        event_map: {
            "company/article/update": {
                "handler": productPriceUpdateHandler,
                "version": '1'
            }
        }
    }
});

module.exports = fdkExtension;

Now Create productPriceUpdateHandler function inside a new file /app/webhook.js and add following code

const { ProductHighlightRecord, PriceDropRecord } = require('./db/mongo')

const productPriceUpdateHandler = async (eventName, { payload }, companyId, applicationId) => {

  // check if payload has articles object or not 
  // if not exists then return
  if (!payload.articles) {
    return 
  } else {
    payload.articles.forEach(async (article) => {
      
      // fetch record from database
      let data = await ProductHighlightRecord.findOne(
        {company_id: companyId, product_item_code: article.item_id}
      )
      
      // check if data is there and price is also there or not
      if (data && data.product.price ) {

        // get old and new price
        let previousPrice = data.product.price.effective
        let newPrice = article.price.effective.max

        // compare both price
        if (previousPrice !== newPrice) {

          // if price is decreased
          if (newPrice < previousPrice || newPrice < previousPrice) {
            
            // saving price drop with TTL of 2 days
            await new PriceDropRecord({product_slug: data.product_slug}).save();
          }

          // update record with new price
          data.product.price.effective.max = newPrice
          data.product.price.effective.min = newPrice
          await data.save();
        }
      }
    })
  }
}

module.exports = { productPriceUpdateHandler };

We'll need to create one POST API for listening to Webhook Event.

add the following API code to /app/server.js file

// webhook handler
app.post('/ext/product-highlight-webhook', async function(req, res) {
  try {
    console.log(`Webhook Event: ${req.body.event} received`)
    await fdkExtension.webhookRegistry.processWebhook(req);
    return res.status(200).json({"success": true});
  } catch(err) {
    console.log(`Error Processing ${req.body.event} Webhook`);
    return res.status(500).json({"success": false});
  }
})

Now Restart the Extension Server and Relaunch the Extension

You can test if Webhook is working or not by updating the price for one of the products for which you have checked enabled price drop from the Extension. Make sure the tunnel and Extension Server keeps running.

Update the price of the product from the Platform Panel

Products > All Products > Search Product by slug > Edit Inventory

edit inventory

Decrease the selling price of the product After waiting for some time visit the PDP of the same product. You should be able to see the Price Drop tag below the price components

price drop tag on sales channel

At Last, We will need to handle the Uninstall event of the Extension open /app/fdk/index.js file, and add the following code to the uninstall callback function

// Write your code here to cleanup data related to extension
// If task is time taking then process it async on other process.
const { company_id } = req.body;
const { ProductHighlightRecord, ProxyRecord } = require('../db/mongo')
await ProductHighlightRecord.bulkWrite([{
    updateMany: {
        "filter": {
            "company_id": company_id
        },
        "update": {
            $set: {
                "is_active": false
            }
        }
    }
}]);
await ProxyRecord.deleteMany({ company_id: company_id });

What you will learn​

Download the Product Highlight example extension​

Adding DB Configuration​

Step 1: Populate test products in your development account​

Step 2: Provide MongoDB configuration​

Step 3: Preview the changes​

Building the extension home page​

Step 1: Create MongoDB schema​

Step 2: Update the backend API​

Step 3: Changes in the Front End​

Step 4: Restart the server and refresh extension page in development account​

Building 'Highlights Listing' page​

Step 1: Create Backend APIs​

Step 2: Create FrontEnd Page​

Step 3: Add CSS for the ProductList component​

Step 4: Create a Route for ProductList component​

Step 5: Restart the extension server and refresh extension page in development account​

Building 'Create Highlight' page​

Step 1: Create Backend APIs​

Step 2: Create FrontEnd page​

Step 3: Add CSS for the CreateHighlight component​

Step 4: Create a Route for CreateHighlight component​

Step 5: Restart the extension server and refresh extension page in development account​

Injecting Javascript into the storefront theme​

Step 1: Create Binding in Extension​

Step 2: Setup Vue project​

Step 3: Create Vue components​

Step 4: Write logic for script injection​

Step 5: Restart the extension server and refresh extension page in development account​

Configuring Webhook​

Now Restart the Extension Server and Relaunch the Extension​

Products > All Products > Search Product by slug > Edit Inventory​

What you will learn

Download the Product Highlight example extension

Adding DB Configuration

Step 1: Populate test products in your development account

Step 2: Provide MongoDB configuration

Step 3: Preview the changes

Building the extension home page

Step 1: Create MongoDB schema

Step 2: Update the backend API

Step 3: Changes in the Front End

Step 4: Restart the server and refresh extension page in development account

Building 'Highlights Listing' page

Step 1: Create Backend APIs

Step 2: Create FrontEnd Page

Step 3: Add CSS for the ProductList component

Step 4: Create a Route for ProductList component

Step 5: Restart the extension server and refresh extension page in development account

Building 'Create Highlight' page

Step 1: Create Backend APIs

Step 2: Create FrontEnd page

Step 3: Add CSS for the CreateHighlight component

Step 4: Create a Route for CreateHighlight component

Step 5: Restart the extension server and refresh extension page in development account

Injecting Javascript into the storefront theme

Step 1: Create Binding in Extension

Step 2: Setup Vue project

Step 3: Create Vue components

Step 4: Write logic for script injection

Step 5: Restart the extension server and refresh extension page in development account

Configuring Webhook

Now Restart the Extension Server and Relaunch the Extension

Products > All Products > Search Product by slug > Edit Inventory