Create a tag list extension
A tag list is a group of tags associated with a product. This tutorial provides steps for creating and installing an extension that displays a tag list on the product details page in a Venia-based storefront.
Prerequisites
Before you start this tutorial, make sure you have a storefront project set up using the steps outlined in the Setup your project topic. This is the storefront you will use to install your extension in this tutorial.
Set up the extension project
Create a folder anywhere in your system and run Yarn's project creation script.
The script starts an interactive questionnaire that helps you fill out your project's package.json
file.
Copied to your clipboardmkdir tagList && \cd tagList && \yarn init
After answering the questions, the yarn CLI creates a package.json
file that looks like the following:
Copied to your clipboard{"name": "tagList","version": "1.0.0","description": "A tag list extension for a PWA Studio storefront","main": "index.js","license": "MIT"}
Create TagList component files
The core purpose of this extension is to provide a React component that renders a list of tags. Use the following command to create a directory and the files that define this component.
Copied to your clipboardmkdir -p src/TagList && \touch src/Taglist/index.js && \touch src/Taglist/tag.js && \touch src/Taglist/tag.css && \touch src/Taglist/tagList.js && \touch src/Taglist/tagList.css
index.js
Exporting modules from your component's index.js
file is a common standard in a React project.
It lets another component import the tag list component using the TagList
directory name.
Copied to your clipboard/* src/TagList/index.js */export { default } from "./tagList";
tag.js
and tag.css
The tag.js
and tag.css
files define a Tag component that renders a single tag in the tag list.
Copied to your clipboard/* src/TagList/tag.js */import React from "react";import Button from "@magento/venia-ui/lib/components/Button";import { Link } from "@magento/venia-ui/lib/drivers";import classes from "./tag.css";const categoryUrlSuffix = ".html";// This is a component responsible for rendering a single tagconst Tag = (props) => {// Destructures the props object into variablesconst { value } = props;const { name, url_path } = value;const url = `/${url_path}${categoryUrlSuffix}`;const buttonClasses = {root_lowPriority: classes.root,content: classes.content,};return (<Link className={classes.link} to={url}><Button classes={buttonClasses} priority="low" type="button">{name}</Button></Link>);};// Make this function the default exported of this moduleexport default Tag;
Copied to your clipboard/* src/TagList.tag.css */.root {border: solid 1px #2680eb;padding: 3px 9px;margin: 5px;border-radius: 6px;}.content {color: #2680eb;font-size: 0.875rem;}
tagList.js
and tagList.css
The tagList.js
and tagList.css
files define the main TagList component this package provides.
It accepts a categoriesListData
object as a prop and renders the data as a tag list.
Copied to your clipboard/* src/TagList/tagList.js */import React from "react";import Tag from "./tag";import classes from "./tagList.css";const TagList = (props) => {// Destructures the props object into variablesconst { categoriesListData } = props;const { categories } = categoriesListData;// Returns nothing if there are no categoriesif (!categories) {return null;}// Converts the array of tag strings into an array of Tag componentsconst tagList = categories.map((category) => {return <Tag key={category.name} value={category} />;});// Returns the list of Tag components inside a div containerreturn <div className={classes.root}>{tagList}</div>;};export default TagList;
Copied to your clipboard/* src/TagList/tagList.css */.root {display: flex;flex-wrap: wrap;}
Add TagList component dependencies
The TagList component requires third party libraries, such as React, to render the correct HTML.
Since this package is an extension, you should list these as peer dependencies in your package.json
file.
This safeguards against including more than one copy of the same dependency in the storefront project and final build.
Use the following command to add the TagList component dependencies as peer dependencies:
Copied to your clipboardyarn add --peer react @magento/venia-ui
This command creates a new peerDependencies
entry in your package.json
file that lists these dependencies.
Copied to your clipboard{"name": "tagList","version": "1.0.0","description": "A tag list extension for a PWA Studio storefront","main": "index.js",- "license": "MIT"+ "license": "MIT",+ "peerDependencies": {+ "@magento/venia-ui": "^6.0.1",+ "react": "^17.0.1"+ }}
Export TagList in extension
Your extension needs to export the TagList component in your project's main entry point to let other developers import it in their code.
The default main entry point for Node packages is the index.js
file, so create this file using the following command:
Copied to your clipboardtouch index.js
Edit the file and add the following content:
Copied to your clipboardexport { default as TagList } from "./src/TagList";
Now, other developers can import the TagList component in their own projects using the following syntax:
Copied to your clipboardimport { TagList } from "tagList";
Create data fetch hook
The TagList component requires data the ProductDetailsFragment does not provide, so you need to create a data fetch hook. The data fetch hook is a custom React hook that sends a GraphQL query requesting the product categories for a product.
Run the following command to create this file:
Copied to your clipboardmkdir -p src/hooks && \touch src/hooks/useProductCategoriesList.js
Edit the file and add the following content:
Copied to your clipboard/* src/hooks/useProductCategoriesList.js */import { useMemo } from "react";import { useQuery } from "@apollo/client";import gql from "graphql-tag";// GraphQL query to fetch a list of categories for a productconst GET_PRODUCT_CATEGORIES = gql`query getProductCategories($urlKey: String!) {products(filter: { url_key: { eq: $urlKey } }) {items {categories {nameurl_path}}}}`;const useProductCategoriesList = (props) => {const { urlKey } = props;const { error, loading, data } = useQuery(GET_PRODUCT_CATEGORIES, {fetchPolicy: "cache-and-network",nextFetchPolicy: "cache-first",variables: {urlKey: urlKey,},});const categories = useMemo(() => {if (data && data.products.items[0]) {return data.products.items[0].categories;}return null;}, [data]);return {error,isLoading: loading,categories,};};export default useProductCategoriesList;
This file requires two new dependencies, @apollo/client
and graphql-tag
.
Run the following command to add these as peer dependencies to the package.json
file:
Copied to your clipboardyarn add --peer @apollo/client graphql-tag
Create wrapper file
A wrapper file exports an interceptor that wraps a module in another file. An interceptor module has access to the original module and the parameters it receives. This lets the interceptor module run the original code along with its own custom logic that can change the incoming parameters or outgoing return value.
For this extension, create a wrapper file for the useProductFullDetails()
hook that calls the data fetch hook you created in a previous step and adds the result to its return value.
First, create this file with the following command:
Copied to your clipboardmkdir -p src/targets/ && \touch src/targets/wrapper.js
Edit this file and add the following content:
Copied to your clipboardimport useProductCategoriesList from "../hooks/useProductCategoriesList";export default (original) => {return function useProductFullDetails(props, ...restArgs) {const { product } = props;// Run the data fetch hookconst categoriesListData = useProductCategoriesList({urlKey: product.url_key,});// Run the original, wrapped functionconst { productDetails, ...defaultReturnData } = original(props,...restArgs);// Add the new data to the data returned by the original functionreturn {...defaultReturnData,productDetails: {...productDetails,categoriesListData: categoriesListData,},};};};
Define intercept file
The intercept file is where you directly interact with Target objects to apply customizations. In this extension, the intercept file tells the build process to use Webpack loaders for ES Modules and CSS Modules. Without these intructions, the build process will not know how to load the files in this extension.
Create this file using the following command:
Copied to your clipboardtouch src/targets/intercept.js
Edit this file and add the following content:
Copied to your clipboardmodule.exports = (targets) => {const { Targetables } = require("@magento/pwa-buildpack");const targetables = Targetables.using(targets);targetables.setSpecialFeatures("esModules", "cssModules");};
This script uses @magento/pwa-buildpack
, so you need to add this library as a dependency.
Copied to your clipboardyarn add --peer @magento/pwa-buildpack
Next, edit your package.json
file to point to the location of this extension's intercept file:
Copied to your clipboard{"name": "tagList","version": "1.0.0","description": "A tag list extension for a PWA Studio storefront","main": "index.js","license": "MIT","peerDependencies": {"@apollo/client": "^3.3.11","@magento/pwa-buildpack": "^8.0.1","@magento/venia-ui": "^6.0.1","graphql-tag": "^2.11.0","react": "^17.0.1"+ },+ "pwa-studio": {+ "targets": {+ "intercept": "src/targets/intercept"+ }}}
Install extension locally
Navigate to your storefront project directory and use the yarn add file:/path/to/local/folder
syntax for the yarn add
CLI to install your extension locally.
For example:
Copied to your clipboardyarn add --dev file:../extensions/tagList
This adds a new entry under devDependencies
in your storefront project's package.json
file that looks like the following:
Copied to your clipboard"style-loader": "~0.23.1",+ "tagList": "file:../extensions/tagList","terser-webpack-plugin": "~1.2.3",
Intercept Venia UI components
All scaffolded projects come with an intercept file called local-intercept.js
.
This file lets you use Targets and Targetables to make modifications to the Venia application code without copying over the source file.
Edit this file so it looks like the following:
Copied to your clipboard/* local-intercept.js */// Import the Targetables managerconst { Targetables } = require("@magento/pwa-buildpack");function localIntercept(targets) {// Create a bound Targetable factoryconst targetables = Targetables.using(targets);// Create a React component targetable linked to the productFullDetail.js fileconst ProductDetails = targetables.reactComponent("@magento/venia-ui/lib/components/ProductFullDetail/productFullDetail.js");// Add an import statement to the productFullDetail.js file and// return the SingleImportStatement objectconst TagList = ProductDetails.addImport("{TagList} from 'tagList'");// Insert the TagList component after the product description and pass in the// new categoriesListData object added to the useProductFullDetails() hookProductDetails.insertAfterJSX("<RichText content={productDetails.description} />",`<${TagList} categoriesListData={productDetails.categoriesListData} />`);// Create an ES Module targetable linked to the useProductFullDetail.js fileconst useProductFullDetails = targetables.esModule("@magento/peregrine/lib/talons/ProductFullDetail/useProductFullDetail.js");// Wrap the useProductFullDetail hook with your extension's wrapper fileuseProductFullDetails.wrapWithFile("useProductFullDetail","tagList/src/targets/wrapper");}module.exports = localIntercept;
Congratulations
You created a tag list extension and installed it in your development server!
Now, when you start your storefront application and navigate to a product page, you will see a list of tags associated with that product.