How To Write a Search Component with Suggestions in React

Stefan Age — Thu, 30 Nov 2017 20:41:12 +0000

Github Repo
This example uses syntax that requires transpiling. See repo for full babel configuration.

Providing search suggestions is a great way to improve user experience. It can save time as well as guide users who are not exactly sure what they are looking for.

With our 'why' identified we can move on to the implementation. But how do we implement suggestions in JavaScript?

As is the case in most problem solving exercises, a good place to start is by asking the right questions:

Is there a library that solves what I'm trying to accomplish and should I use it? A quick google search returns options like autocomplete.js, but there is valuable insight to be gained by writing our own.
What HTML elements are we operating with? Looks like we could use <form>, <input/>, <ul>.

We've decided to write our own.

What we'll need:

A source of information. We're after a collection of values to compare against what our user has entered (we'll source an API response, but you could also use a local array of values).
An HTTP client. Allows us to make requests to specific endpoints to GET the data we're looking for. I chose axios since it gives us some additional features over the Fetch API such as automatic parsing of the data it receives.
A smart/container component that makes API calls referencing a controlled input.
A presentational (stateless functional) component for displaying the results.

Lets start with our container, Search:

import React, { Component } from 'react'

class Search extends Component {
 state = {
   query: '',
 }

 handleInputChange = () => {
   this.setState({
     query: this.search.value
   })
 }

 render() {
   return (
     <form>
       <input
         placeholder="Search for..."
         ref={input => this.search = input}
         onChange={this.handleInputChange}
       />
       <p>{this.state.query}</p>
     </form>
   )
 }
}

export default Search

You'll notice that as you type into the input field, Search re-renders and our input's value is shown below. Thanks to refs we can select the input element and do useful things such as getting its value or invoking DOM events like focus (this.search.focus()).

Next, let's wire in an API. Here we'll use MusicGraph, a database of music information. Grab an API key here.

We'll use axios to create a getInfo method (check your API's docs on how to structure your request URL):

  getInfo = () => {
    axios.get(`${API_URL}?api_key=${API_KEY}&prefix=${this.state.query}&limit=7`)
      .then(({ data }) => {
        this.setState({
          results: data.data
        })
      })
  }

Axios .get returns a promise meaning it does not block the rest of the application from executing while it waits for an API response. Here we are making a request to the MovieGraph API's artist endpoint, using the magic of refs to populate the prefix query parameter. (API_URL and API_KEY are being defined above the class definition, see next snapshot.)

Let's also tweak the handleInputChange method. We don't need to make an API call for every single onChange event, or when the input is cleared.

The full component so far:

import React, { Component } from 'react'
import axios from 'axios'

const { API_KEY } = process.env
const API_URL = 'http://api.musicgraph.com/api/v2/artist/suggest'

class Search extends Component {
  state = {
    query: '',
    results: []
  }

  getInfo = () => {
    axios.get(`${API_URL}?api_key=${API_KEY}&prefix=${this.state.query}&limit=7`)
      .then(({ data }) => {
        this.setState({
          results: data.data // MusicGraph returns an object named data, 
                             // as does axios. So... data.data                             
        })
      })
  }

  handleInputChange = () => {
    this.setState({
      query: this.search.value
    }, () => {
      if (this.state.query && this.state.query.length > 1) {
        if (this.state.query.length % 2 === 0) {
          this.getInfo()
        }
      } 
    })
  }

  render() {
    return (
      <form>
        <input
          placeholder="Search for..."
          ref={input => this.search = input}
          onChange={this.handleInputChange}
        />
        <p>{this.state.query}</p>
      </form>
    )
  }
}

export default Search

If you have React Dev Tools installed in your browser you can watch the state of Search change as the API calls complete:

Home stretch. Now to render our results to the DOM.

As mentioned at setup let's create our presentational component, Suggestions.

import React from 'react'

const Suggestions = (props) => {
  const options = props.results.map(r => (
    <li key={r.id}>
      {r.name}
    </li>
  ))
  return <ul>{options}</ul>
}

export default Suggestions

We've setup Suggestions to expect a prop named results.

Let's render our Suggestions component:

import React, { Component } from 'react'
import axios from 'axios'
import Suggestions from 'components/Suggestions'

const { API_KEY } = process.env
const API_URL = 'http://api.musicgraph.com/api/v2/artist/suggest'

class Search extends Component {
  state = {
    query: '',
    results: []
  }

  getInfo = () => {
    axios.get(`${API_URL}?api_key=${API_KEY}&prefix=${this.state.query}&limit=7`)
      .then(({ data }) => {
        this.setState({
          results: data.data
        })
      })
  }

  handleInputChange = () => {
    this.setState({
      query: this.search.value
    }, () => {
      if (this.state.query && this.state.query.length > 1) {
        if (this.state.query.length % 2 === 0) {
          this.getInfo()
        }
      } else if (!this.state.query) {
      }
    })
  }

  render() {
    return (
      <form>
        <input
          placeholder="Search for..."
          ref={input => this.search = input}
          onChange={this.handleInputChange}
        />
        <Suggestions results={this.state.results} />
      </form>
    )
  }
}

export default Search

Try it out:

It works!

Once routing is setup, we can wrap each result in an anchor/react-router Link component. But that is a topic for another post. Until then, I hope this was helpful to someone!

Hi, I'm Stefan

Stefan Age — Fri, 02 Jun 2017 15:11:54 +0000

I have been coding for 1 year.

You can find me on GitHub as Sage911

I live in Dallas, TX

I mostly program in these languages: Node, React, Ruby, Ruby On Rails.

I am currently learning more about RoR.

Nice to meet you.

DEV Community: Stefan Age

How To Write a Search Component with Suggestions in React

We've decided to write our own.

What we'll need:

Hi, I'm Stefan