Using Opencage Gecoder API with REACT
Arnaud Ferrand
Posted on March 22, 2020
Photo by Kelsey Knight on Unsplash
π 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 donβt 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, weβre 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
\[1/4\] π Resolving packages...
\[2/4\] π Fetching packages...
\[3/4\] π Linking dependencies...
\[4/4\] π Building fresh packages...
success Saved lockfile.
success Saved 11 new dependencies.
info Direct dependencies
ββ react-dom@16.5.2
ββ react-scripts@2.0.5
ββ react@16.5.2
info All dependencies
ββ babel-plugin-dynamic-import-node@2.2.0
ββ babel-preset-react-app@5.0.4
ββ confusing-browser-globals@1.0.4
ββ eslint-config-react-app@3.0.4
ββ eslint-plugin-jsx-a11y@6.1.2
ββ object.assign@4.1.0
ββ react-dev-utils@6.0.5
ββ react-dom@16.5.2
ββ react-error-overlay@5.0.5
ββ react-scripts@2.0.5
ββ react@16.5.2
β¨ 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 canβt go back!We suggest that you begin by typing: cd opencage-react-app
yarn startHappy hacking!
Start hacking
First part
Letβs 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 letβs 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
\[1/4\] π Resolving packages...
\[2/4\] π Fetching packages...
\[3/4\] π Linking dependencies...
\[4/4\] π Building fresh packages...success Saved lockfile.
success Saved 3 new dependencies.
info Direct dependencies
ββ bulma@0.7.2
ββ react-dom@16.5.2
ββ react@16.5.2
info All dependencies
ββ bulma@0.7.2
ββ react-dom@16.5.2
ββ react@16.5.2
β¨ Done in 8.61s.
letβs 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 GeocodingForm
and 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 letβs 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.
Resources
- Opencage Data Geocoder: https://opencagedata.com/
- Source code repository on github : https://github.com/tsamaya/opencage-react-guide
- Demo version on netlify : https://unruffled-kirch-3cd76e.netlify.com/
Posted on March 22, 2020
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