Easy APIs using Strapi - a NodeJS Headless CMS

20 May, 2020

Recently while watching Jason Lengstorf's Twitch, he featured Chris Sevilleja (aka Scotch.io) who presented a headless NodeJS CMS and API called StrapiJS. I've had experience with headless CMS in the past in PHP world (Wordpress, Directus, etc), and I was pumped by the prospect of having a JavaScript based solution that would blend better in a React stack.

Looking into it, they recently released a 3.0 beta, so I thought it'd be a great time to try out the new API and docs. I tested it out and took some notes on the process, as well as some tips that weren't particularly clear (or present) in the docs. We'll create an API and connect a NextJS app to it.

Setting up a Strapi project

I installed Strapi per the CLI documentation. It was really simple, and only a few steps. I appreciate when a team takes the time to put together a CLI to walk you through the setup and handle common tasks (like installing deps).

You can create a new Strapi project and install the dependencies by running one command:

yarn create strapi-app my-project --quickstart

This creates a new Strapi project connected to a SQLite database. If you prefer to use a different database connection, remove the โ€”quickstart from the command above to be prompted for a database connection in the CLI walkthrough.

Then you can run the development server from inside the project directory using this command:

yarn develop

After running spinning up the development server, you should see a bit of output in the console, like the URL for your API (http://localhost:1337/) - as well as an Admin page (http://localhost:1337/admin).

Screen_Shot_2020-05-19_at_12.36.09_PM.jpg

Head over to the Admin page, login, and start creating "collections" (aka DB tables and columns). Or you can create "Single" types, which are basically APIs for pages and their data (ala Wordpress pages with custom fields). There's even a handy Getting Started video guide that helps you understand the workflow and UI.

Screen_Shot_2020-05-19_at_12.36.15_PM.jpg

What you get ๐Ÿ“ฆ

  • Rest API
  • "Admin" CMS
  • User authentication using JWT
  • User roles and permissions

By default your database will come preloaded with users, permission, and role tables.

Creating a basic API

I spent time creating a small API for a freelance time tracking app (more on that soon ๐Ÿ‘€). I needed 3 tables: projects, clients, and hours. They were very simple with a few text fields each, and a couple had simple one-to-one relationships with eachother.

./Screen_Shot_2020-05-19_at_12.49.11_PM.jpg

I created the tables and columns using the CMS, and added one test item in each table. Then to access the API, I visited http://localhost:1337/clients. In less than 10 minutes or so I had a working API with modeled content.

Private user content

I wanted to make sure that the content was protected from the public, and that anyone accessing the API would require authorization. Strapi made this fairly simple with "Roles and Permissions".

./Screen_Shot_2020-05-19_at_12.49.24_PM.jpg

My first thought was to create a new user, add them to the Authenticated role, and try querying the API with that user. It didn't work at first ๐Ÿ™…๐Ÿปโ€โ™‚๏ธ. This was because the Authenticated role doesn't automatically gain permissions for "collections" you create. If you edit the Authenticated role and enable the collections you want to access, it should work ๐Ÿ‘

I opted to create a new user role (App User) to encompass this new level of permission (as a kind of "admin" role), and that way Authenticated users could have more restricted privileges (in my case, maybe accounting oversight).

./Screen_Shot_2020-05-19_at_12.49.38_PM.jpg

Generating JWT tokens

Once you've created a user, assigned them a role that has permission to view content - you can finally generate a JWT (aka API token) to access private API endpoints.

Send POST request to http://localhost:1337/auth/local with application/json and the body as:

{
"identifier": "username-or-email",
"password": "strongPassword"
}

API will return something like:

{
"jwt": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwiaWF0IjoxNTg5MjM1Mjc2LCJleHAiOjE1OTE4MjcyNzZ9.KtpTQgI7MNHvWUkQ0hPeops4ZwzP2grRFFR3OH3hB9Q",
"user": {
"id": 1,
"username": "whoisryosuke",
"email": "ryosuke.san.hana@gmail.com",
"provider": "local",
"confirmed": true,
"blocked": false,
"role": {
"id": 1,
"name": "Authenticated",
"description": "Default role given to authenticated user.",
"type": "authenticated"
},
"created_at": "2020-05-11T21:31:17.526Z",
"updated_at": "2020-05-11T21:31:17.529Z"
}
}

Authorizing users with JWT requires that the user's role has callback enabled. By default, users are in the Authenticated role which has callback enabled by default as well.

To enable for a new role: Go to the Strapi admin > User Roles & Permissions > Click the user role > Click the User Permissions accordion to expand it > Check the callback checkbox if it isn't already.

Using the JWT

Once you have generated the JWT using the /auth/local/ endpoint, you can use the JWT in the "headers" of your API request as a "Bearer token".

Here's an example of a GET request using fetch() with the JWT (or "token") attached to the headers:

const token = Cookies.get('your-cookie-key')
fetch('http://localhost:1337/clients', {
method: 'get',
headers: new Headers({
Authorization: 'Bearer ' + token,
'Content-Type': 'application/json',
}),
})

This works great, but I feel like with every API you end up writing a wrapper around fetch to handle these repetitive operations (like regular vs authenticated requests, hitting common endpoints, etc). In my search I found that Strapi has a SDK for JavaScript that offers this kind of functionality with an easy to use API.

If you already have a JWT token, you get use the setToken method on the Strapi class to authorize further requests:

// Grab token from cookies
const token = Cookies.get(TOKEN_COOKIES_KEY)
// Create a new instance of Strapi with the API URL
const strapi = new Strapi('http://localhost:1337/')
// Set the JWT token for headers
strapi.setToken(token)
// Fetch any content that requires auth
const posts = strapi.getEntries('table-name')

Creating Authorization Component

We need a component that can wrap any private pages, check if the user is logged in, and redirect any unauthorized users away (or show content if authorized). Ideally you should validate the token, but for sake of simplicity, we let the user in if they have a token at all (if they don't, the private API requests will still fail):

import { useEffect, useState } from 'react'
import { useRouter } from 'next/router'
import Cookies from 'js-cookie'
import { TOKEN_COOKIES_KEY } from '../constants'
export default function AuthGuard({ children }) {
const [loggedIn, setLoggedIn] = useState(false)
const router = useRouter()
const token = Cookies.get(TOKEN_COOKIES_KEY)
// Grab JWT from cookies
// If no cookie, redirect to login page
useEffect(() => {
if (token && !loggedIn) {
// Validate token here
return setLoggedIn(true)
}
if (!loggedIn) router.push('/login')
}, [loggedIn])
if (loggedIn) return children
return <div>Not authorized, redirecting to login</div>
}

In order for this to work, we need a way for the user to login and store the token in cookies. I made a basic login form using Chakra UI. It submits the user data to authorization endpoint in the Strapi API:

import { useState } from 'react'
import Link from 'next/link'
import Head from 'next/head'
import { useRouter } from 'next/router'
import Cookies from 'js-cookie'
import Strapi from 'strapi-sdk-javascript'
import { motion } from 'framer-motion'
import { Box, Button, Input, Stack } from '@chakra-ui/core'
import { TOKEN_COOKIES_KEY } from '../constants'
import { useUser } from '../context/UserContext'
import BaseLayout from '../layouts/BaseLayout'
const Login = () => {
const [formData, setFormData] = useState({
identifier: '',
password: '',
})
const router = useRouter()
const { updateUser } = useUser()
const onChange = ({ currentTarget: { name, value } }) => {
setFormData(prevState => ({ ...prevState, [name]: value }))
}
const submitForm = async e => {
e.preventDefault()
const strapi = new Strapi('http://localhost:1337/')
let response
try {
response = await strapi.login(formData.identifier, formData.password)
} catch (e) {
// Login failed
}
// Login succeeded
if (response) {
// Save JWT in cookies
Cookies.set(TOKEN_COOKIES_KEY, response.jwt)
// Save user info to context
updateUser(response.user)
// Redirect user to dashboard
router.push('/')
}
}
return (
<BaseLayout>
<Head>
<title>Login</title>
<link rel="icon" href="/favicon.ico" />
</Head>
<Box textAlign="center">
<form method="POST" onSubmit={submitForm}>
<Stack spacing={3}>
<Input
name="identifier"
placeholder="Username"
value={formData.identifier}
onChange={onChange}
/>
<Input
name="password"
type="password"
placeholder="Password"
value={formData.password}
onChange={onChange}
/>
<Button type="submit" onClick={submitForm}>
Login
</Button>
</Stack>
</form>
</Box>
</BaseLayout>
)
}
export default Login

Ideally you should use a library like Yup to validate the form beyond relying on the HTML5 validation attributes.

And then to get the user data across the app, we create a context provider that queries the user API and pass it to the context. Ideally here if the user check fails, we could invalidate the user logged in status (if it was in context, or we combined the AuthGuard and this provider):

import React, { createContext, useContext, useEffect, useState } from 'react'
import Strapi from 'strapi-sdk-javascript'
import Cookies from 'js-cookie'
import { TOKEN_COOKIES_KEY } from '../constants'
export const UserContext = createContext()
export const UserProvider = ({ children }) => {
const [user, updateUser] = useState({})
const token = Cookies.get(TOKEN_COOKIES_KEY)
useEffect(() => {
const fetchUser = async () => {
const strapi = new Strapi('http://localhost:1337/')
strapi.setToken(token)
const profile = await strapi.getEntries('users/me')
if (profile) updateUser(profile)
}
if (Object.keys(user).length === 0) {
fetchUser()
}
}, [user, token])
return (
<UserContext.Provider value={{ user, updateUser }}>
{children}
</UserContext.Provider>
)
}
export const useUser = () => {
return useContext(UserContext)
}

Working with Dates

A great example of "it just works" out of the box was working with dates. I had a collection called hours that had two columns for "start" and "end" date times. It was supposed to represent a time range that could later be parsed into the number of hours spent working.

You can filter dates by using the "greater than" gte and "less than" lte filter parameters (if you have your column set to date or datetime).

When filtering collections with the SDK, you can use the getEntries() method, but the SDK docs don't specify what format the query params need to be. Looking at the underlying code, you can see it's just a wrapper around axios and passing a params object to that. Checking the axios docs, it seems like you just create an object where the keys are column names and values are the filter value.

In this case, I grab hours between two dates:

const latestHours = await strapi.getEntries('hours', {
// Column name (and _filtertype): filter/search value
start_gte: formatISO(dateRange.start),
end_lte: formatISO(dateRange.end),
})

What broke for me

As much as it was a fairly easy process, I hit big snags that left me clueless for a 5-10 minutes.

  • Don't create a UID column for id. Strapi automatically creates auto-incrementing IDs for your collections. If you add one named id specifically, it will break the API completely. If you happen to create one accidentally, go into model file and remove the column from the schema.
  • Titles of columns are 1:1, meaning the API will display the property/column in uppercase if set. Keep this in mind when consuming the API, accessing the parameter will be case sensitive (i.e. getting the item.Description).
  • When you login users using the /auth/local endpoint, if the user details are incorrect the form will return error code 400 Bad Request. Try real auth details and see if you get a valid response with JWT and user details.
  • CORS are enabled by default. Make sure to add your frontend app URL to the allowed origin list or make it * to allow all URLs. Settings are located in different places for each app env (dev, production, etc) โ€” config/environments/development/security.json.

Despite these hiccups, I was fairly happy with the experience. If you don't fuss with CORS once in your API, you're doing something wrong ๐Ÿ˜‚

Adding GraphQL

One of the coolest parts of Strapi was the ability to basically turn GraphQL on with the flip of a switch. By running one install script you can enable a GraphQL endpoint (complete with CRUD mutations), as well as GraphQL Playground (a UI for creating queries).

Install the necessary plugins:

yarn strapi install graphql
# npm run strapi install graphql

Then start the dev server and navigate to http://localhost:1337/graphql. You'll see a GraphQL Playground.

Install the ModHeader browser extension to set the Authorization header in your request. Or use an app like Insomnia, Postwoman, etc to apply the appropriate headers and query the GraphQL endpoint.

./Screen_Shot_2020-05-19_at_10.05.45_AM.jpg

Querying the Strapi GraphQL endpoint using Insomnia (and showing the autocomplete from schema)

Setting up a NextJS App with Apollo Client

To test out the GraphQL API with a React app, I spun up a quick NextJS app with the create-next-app CLI. Then I installed the basic Apollo Client dependencies. The latest version of Apollo is big on React context and hooks, allowing you to query GraphQL inside functional components using a useQuery hook. As long as the app is wrapped in an <ApolloProvider>, it gives nested components access to the Apollo "client" using React's context.

Wrap _app.js in a <ApolloProvider> and pass it an instantiated Apollo client:

import React from 'react'
import ApolloClient from 'apollo-boost'
import { ApolloProvider } from '@apollo/react-hooks'
const token = 'JWT-token-here'
const client = new ApolloClient({
uri: 'http://localhost:1337/graphql',
headers: {
authorization: token ? `Bearer ${token}` : '',
},
})
export default ({ Component, pageProps }) => (
<ApolloProvider client={client}>
<Component {...pageProps} />
</ApolloProvider>
)

Create a component that uses Apollo and queries GraphQL using a React hook:

import React from 'react'
import { useQuery } from '@apollo/react-hooks'
import { gql } from 'apollo-boost'
const GET_CLIENTS = gql`
{
clients {
Name
Description
Color
}
}
`
export default function Clients() {
const { loading, error, data } = useQuery(GET_CLIENTS)
if (loading) return <p>Loading...</p>
if (error) return <p>Error :(</p>
return <div>{JSON.stringify(data)}</div>
}

If you add this component to any NextJS page you should see a loading state, then the data from GraphQL. If you see an error, make sure you have permissions setup properly for the endpoint you're accessing.

API in 1-2-3

I'm really impress with Strapi and how easy it was to use. Definitely faster than booting up an a custom Express server or an Adonis/Nest project. The only thing comparably faster would be generating an API from a Swagger/OpenAPI blueprint, and even then, that requires more startup knowledge.

I could definitely see this becoming a standard in my own workflow, and I hope it helps expedite your full stack or backend process as well. And with platforms like DigitalOcean offering new droplets with Strapi as a one-click install, it makes the process of deploying a production API even more seamless.

Cheers, Ryo

References

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@Ryosuke2 months ago