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Build an API for your front end using Pages Functions

Last reviewed: over 1 year ago

In this tutorial, you will build a full-stack Pages application. Your application will contain:

  • A front end, built using Cloudflare Pages and the React framework.
  • A JSON API, built with Pages Functions, that returns blog posts that can be retrieved and rendered in your front end.

If you prefer to work with a headless CMS rather than an API to render your blog content, refer to the headless CMS tutorial.

Build your front end

To begin, create a new Pages application using the React framework.

Create a new React project

In your terminal, create a new React project called blog-frontend using the create-react-app command. Go into the newly created blog-frontend directory and start a local development server:

Create a new React application
npx create-react-app blog-frontend
cd blog-frontend
npm start

Set up your React project

To set up your React project:

  1. Install the React Router in the root of your blog-frontend directory.

With npm:

Terminal window
npm install react-router-dom@6

With yarn:

Terminal window
yarn add react-router-dom@6
  1. Clear the contents of src/App.js. Copy and paste the following code to import the React Router into App.js, and set up a new router with two routes:
import { Routes, Route } from "react-router-dom";
import Posts from "./components/posts";
import Post from "./components/post";
function App() {
return (
<Routes>
<Route path="/" element={<Posts />} />
<Route path="/posts/:id" element={<Post />} />
</Routes>
);
}
export default App;
  1. In the src directory, create a new folder called components.
  2. In the components directory, create two files: posts.js, and post.js. These files will load the blog posts from your API, and render them.
  3. Populate posts.js with the following code:
import React, { useEffect, useState } from "react";
import { Link } from "react-router-dom";
const Posts = () => {
const [posts, setPosts] = useState([]);
useEffect(() => {
const getPosts = async () => {
const resp = await fetch("/api/posts");
const postsResp = await resp.json();
setPosts(postsResp);
};
getPosts();
}, []);
return (
<div>
<h1>Posts</h1>
{posts.map((post) => (
<div key={post.id}>
<h2>
<Link to={`/posts/${post.id}`}>{post.title}</Link>
</h2>
</div>
))}
</div>
);
};
export default Posts;
  1. Populate post.js with the following code:
import React, { useEffect, useState } from "react";
import { Link, useParams } from "react-router-dom";
const Post = () => {
const [post, setPost] = useState({});
const { id } = useParams();
useEffect(() => {
const getPost = async () => {
const resp = await fetch(`/api/post/${id}`);
const postResp = await resp.json();
setPost(postResp);
};
getPost();
}, [id]);
if (!Object.keys(post).length) return <div />;
return (
<div>
<h1>{post.title}</h1>
<p>{post.text}</p>
<p>
<em>Published {new Date(post.published_at).toLocaleString()}</em>
</p>
<p>
<Link to="/">Go back</Link>
</p>
</div>
);
};
export default Post;

Build your API

You will now create a Pages Functions that stores your blog content and retrieves it via a JSON API.

Write your Pages Function

To create the Pages Function that will act as your JSON API:

  1. Create a functions directory in your blog-frontend directory.
  2. In functions, create a directory named api.
  3. In api, create a posts.js file in the api directory.
  4. Populate posts.js with the following code:
import posts from "./post/data";
export function onRequestGet() {
return Response.json(posts);
}

This code gets blog data (from data.js, which you will make in step 8) and returns it as a JSON response from the path /api/posts.

  1. In the api directory, create a directory named post.
  2. In the post directory, create a data.js file.
  3. Populate data.js with the following code. This is where your blog content, blog title, and other information about your blog lives.
const posts = [
{
id: 1,
title: "My first blog post",
text: "Hello world! This is my first blog post on my new Cloudflare Workers + Pages blog.",
published_at: new Date("2020-10-23"),
},
{
id: 2,
title: "Updating my blog",
text: "It's my second blog post! I'm still writing and publishing using Cloudflare Workers + Pages :)",
published_at: new Date("2020-10-26"),
},
];
export default posts;
  1. In the post directory, create an [[id]].js file.
  2. Populate [[id]].js with the following code:
[[id]].js
import posts from "./data";
export function onRequestGet(context) {
const id = context.params.id;
if (!id) {
return new Response("Not found", { status: 404 });
}
const post = posts.find((post) => post.id === Number(id));
if (!post) {
return new Response("Not found", { status: 404 });
}
return Response.json(post);
}

[[id]].js is a dynamic route which is used to accept a blog post id.

Deploy

After you have configured your Pages application and Pages Function, deploy your project using the Wrangler or via the dashboard.

Deploy with Wrangler

In your blog-frontend directory, run wrangler pages deploy to deploy your project to the Cloudflare dashboard.

Terminal window
wrangler pages deploy blog-frontend

Deploy via the dashboard

To deploy via the Cloudflare dashboard, you will need to create a new Git repository for your Pages project and connect your Git repository to Cloudflare. This tutorial uses GitHub as its Git provider.

Create a new repository

Create a new GitHub repository by visiting repo.new. After creating a new repository, prepare and push your local application to GitHub by running the following commands in your terminal:

Terminal window
git init
git remote add origin https://github.com/<YOUR-GH-USERNAME>/<REPOSITORY-NAME>
git add .
git commit -m "Initial commit"
git branch -M main
git push -u origin main

Deploy with Cloudflare Pages

Deploy your application to Pages:

  1. Log in to the Cloudflare dashboard and select your account.
  2. In Account Home, select Workers & Pages > Create application > Pages > Connect to Git.
  3. Select the new GitHub repository that you created and, in the Set up builds and deployments section, provide the following information:
Configuration optionValue
Production branchmain
Build commandnpm run build
Build directorybuild

After configuring your site, begin your first deploy. You should see Cloudflare Pages installing blog-frontend, your project dependencies, and building your site.

By completing this tutorial, you have created a full-stack Pages application.