diff --git a/README.md b/README.md index f21d7f1..f64fb2e 100644 --- a/README.md +++ b/README.md @@ -4,12 +4,14 @@ [![Donate](https://img.shields.io/beerpay/trevorblades/countries.svg)](https://beerpay.io/trevorblades/countries) -A public GraphQL API for information about countries, continents, and languages. This project uses [Countries List](https://annexare.github.io/Countries/) as a data source, so the schema follows the shape of that data, with a couple exceptions: +A public GraphQL API for information about countries, continents, and languages. This project uses [Countries List](https://annexare.github.io/Countries/) as a data source, so the schema follows the shape of that data, with a few exceptions: 1. The codes used to key the objects in the original data are available as a `code` property on each item returned from the API. 2. The `continent` and `languages` properties are now objects and arrays of objects, respectively. -## Writing queries +## Querying + +In: ```graphql { @@ -26,6 +28,8 @@ A public GraphQL API for information about countries, continents, and languages. } ``` +Out: + ```json { "data": { @@ -45,30 +49,38 @@ A public GraphQL API for information about countries, continents, and languages. } ``` -Check out the [playground](https://countries.trevorblades.com) to explore the schema and test out some queries. +Check out [the playground](https://countries.trevorblades.com) to explore the schema and test out some queries. ## Example -A practical use of this API is to create a country select input that doesn't require you to include a large dataset of country info in your bundle. +One practical use of this API is to create a country select field that fetches its options dynamically. Normally, you would need to install an npm package or create a file in your project containing the necessary data -- usually country codes and names -- and bundle that data with your app code. This results in a lot of extra kilobytes hanging around in your bundle for a feature that might not always get rendered or used. Here's what that data size looks like: -In this example, we'll be using [React](https://reactjs.org/) and the [Apollo](https://apollographql.com) GraphQL client. First, we'll install all of our dependencies: +- **50.1 KB** using the `countries` export from [Countries List](https://annexare.github.io/Countries/) +- **14.2 KB** using this API (~70% smaller) + +In this example, I'll be using [React](https://reactjs.org/) and some [Apollo](https://apollographql.com) tools. Apollo's GraphQL client and React components make it simple to execute, handle, and cache GraphQL queries. You can also accomplish this by sending a POST request to this API using `fetch` or your favourite request library, but I won't cover that in this example. + +### Install dependencies ```shell $ npm install react react-dom react-apollo apollo-boost graphql graphql-tag ``` -50.1 KB with `countries-list` -14.2 KB with Countries GraphQL +### Build a React component ```js -import React from 'react'; -import ReactDOM from 'react-dom'; import ApolloClient from 'apollo-boost'; +import React, {Component} from 'react'; +import ReactDOM from 'react-dom'; +import gql from 'graphql-tag'; +import {Query} from 'react-apollo'; +// initialize our Apollo GraphQL client const client = new ApolloClient({ uri: 'https://countries.trevorblades.com' }); +// write a GraphQL query that asks for names and codes for all countries const GET_COUNTRIES = gql` { countries { @@ -79,38 +91,45 @@ const GET_COUNTRIES = gql` `; class App extends Component { - state = { - country: '' - }; + constructor(props) { + super(props); - onCountryChange = event => + // set a default value + this.state = { + country: 'US' + }; + } + + // set the selected country to the new input value + onCountryChange(event) { this.setState({country: event.target.value}); + } render() { return ( - - - {({loading, error, data}) => { - if (loading) return

Loading...

; - if (error) return

{error.message}

; - return ( - - ); - }} -
-
+ + {({loading, error, data}) => { + if (loading) return

Loading...

; + if (error) return

{error.message}

; + return ( + + ); + }} +
); } } ReactDOM.render(, document.getElementById('root')); ``` + +### Behold, your mighty country select 🎉