Arnaud Ferrand

Posted on Mar 22, 2020 • Updated on Jun 18, 2023

Using Opencage Gecoder API with REACT

#javascript #react #geocoder #opencage

Photo by Kelsey Knight on Unsplash

🆕 Newer version available Using OpenCage Gecoder API with React (2nd-edition)

This post was previously published on Medium

Overview

In this tutorial, we will discuss about the integration of Opencage API into a React application.

The prerequisites are, of course, a OpenCage API key, (if you don’t have one, simply use this free registration link), a node platform with yarn or npm; and finally your favourite IDE or Text Editor.

I assume you are familiar with JavaScript. In this tutorial, we’re going to use some ES6 features like arrow functions, classes, let, and const statements.

This tutorial is not about setting up a build environment for React, so for the easy use, we will use create-react-app.

Before we start, here is the source code. And a live version can be found here.

Setup the environment

As current node version, when writing this guide, is 10.12; I assume you can use npx as it is available since version 5.2.

$ npx create-react-app opencage-react-app

it outputs :

Creating a new React app in \[...\]/opencage-react-app.Installing packages. This might take a couple of minutes.  
Installing react, react-dom, and react-scripts...yarn add v1.10.1  
\[1/4\] 🔍  Resolving packages...  
\[2/4\] 🚚  Fetching packages...  
\[3/4\] 🔗  Linking dependencies...  
\[4/4\] 📃  Building fresh packages...  
success Saved lockfile.  
success Saved 11 new dependencies.  
info Direct dependencies  
├─ react-dom@16.5.2  
├─ react-scripts@2.0.5  
└─ react@16.5.2  
info All dependencies  
├─ babel-plugin-dynamic-import-node@2.2.0  
├─ babel-preset-react-app@5.0.4  
├─ confusing-browser-globals@1.0.4  
├─ eslint-config-react-app@3.0.4  
├─ eslint-plugin-jsx-a11y@6.1.2  
├─ object.assign@4.1.0  
├─ react-dev-utils@6.0.5  
├─ react-dom@16.5.2  
├─ react-error-overlay@5.0.5  
├─ react-scripts@2.0.5  
└─ react@16.5.2  
✨  Done in 79.89s.Initialized a git repository.Success! Created opencage-react-app at \[...\]/opencage-react-app  
Inside that directory, you can run several commands: yarn start  
    Starts the development server. yarn build  
    Bundles the app into static files for production. yarn test  
    Starts the test runner. yarn eject  
    Removes this tool and copies build dependencies, configuration files  
    and scripts into the app directory. If you do this, you can’t go back!We suggest that you begin by typing: cd opencage-react-app  
  yarn startHappy hacking!

Start hacking

First part

Let’s do the suggested commands

$ cd opencage-react-app  
$ yarn start

The project is built in development mode and it opens your favourite browser on http://localhost:3000.

The page will automatically reload if you make changes to the code. So let’s do it.

First of all download opencage svg logo and copy it to the src/ folder

Open your IDE or Text Editor with the folder opencage-react-app

Edit the file ./src/App.js

replace

import logo from './logo.svg';

with

import logo from './opencage-white.svg';

The app is rebuilt and instead of the atomic react logo, you should now have a Open Cage logo.

use CTRL + C to stop the development server.

We will now add dependencies to the project.

First the style, you can pick up your favourite CSS framework (flexbox, bootstrap or material UI), for this tutorial I picked up Bulma as it is javascript free, then no react wrapper is needed to keep this tutorial simple and focused only on opencage geocode API integration.

$ yarn add bulma

it outputs

yarn add v1.10.1  
\[1/4\] 🔍  Resolving packages...  
\[2/4\] 🚚  Fetching packages...  
\[3/4\] 🔗  Linking dependencies...  
\[4/4\] 📃  Building fresh packages...success Saved lockfile.  
success Saved 3 new dependencies.  
info Direct dependencies  
├─ bulma@0.7.2  
├─ react-dom@16.5.2  
└─ react@16.5.2  
info All dependencies  
├─ bulma@0.7.2  
├─ react-dom@16.5.2  
└─ react@16.5.2  
✨  Done in 8.61s.

let’s create an Header component:

Rename App.css into Header.css. Then edit Header.css, we will avoid being see sick with the infinite loop animation and place the center text in the header only. The header will be a header not whole view port page.

Create ./src/Header.js file:

Edit ./src/index.js, adding

import 'bulma/css/bulma.css';

after

import './index.css';

now edit App.js, we first use the Header Component and then we prepare 2 columns.

Now add packages dependencies like the opencage API client, LeafletJS, and classnames:

$ yarn add opencage-api-client leaflet classnames

opencage-api-client is the client library for Opencage Geocoder API
LeafletJS is the well-known web mapping API
classnames is a javascript utility lib to help build className attributes

We can start the dev server with $ yarn start

For now the app looks like this

In the first column we will set up the form with the search input parameters. In the second column, we will have the results as multiple tabs, starting with the readable results (formatted address and coordinates), and a second tab with the raw JSON result from the API. As you can see in the following design, we will create two main components and GeocodingFormand GeocodingResults

Create a file ./src/GeocodingForm.js

Then create a file ./src/GeocodingResults.js

We need to create files ./src/ResultList.js and ./src/ResultJSON.js

To finish the first part, wire the application with those two main components (GeocodingForm and GeocodingResults)

Edit the ./src/App.js file, first the imports:

now add a constructor

the App handles input text changes and the submit.

So first add the handleChange method

Followed by the handleSubmit method

Last touch for this first part, we add the main components in the render method:

Here is what the app now looks like

Second part

In this part we will add a map tab in the result section.

First let’s create a ./src/ResultMap.js file :

Download the pin icon from marker-icon-red.png and save it to public/ folder.

As the map needs a height, we create a ./src/ResultMap.css file :

Back in ./src/GeocodingResuls.js add the tab in the ul _s_ection

and with the other results content add the map:

The app now contains a map

I really hope this was helpful for you. If it was, please, do let me know so that I can write more posts like this. You can always reach me out on Twitter and again if you followed this tutorial along till the end, I am really proud of you guys.