How to Build Great React Search Experiences Quickly

How to Build Great React Search Experiences Quickly

How to Build Great React Search Experiences Quickly.We'll walkthrough how to build excellent, React-based search experiences using Elastic's open source Search UI library

Building search experiences is hard work. It can seem easy at a glance: build a search bar, put data into a database, then have user input fuel queries against the database. But there are many things to consider in the data modeling, underlying logic and — of course — the overall design and user experience.

We’ll walkthrough how to build excellent, React-based search experiences using Elastic’s open source Search UI library. It’ll take about 30 minutes and afterwards you’ll be ready to bring search to any application.

But first, what is it that makes building search so challenging?

Search Is Hard

A great article made the rounds a few weeks ago titled Falsehoods Programmers Believe About Search. It contains an exhaustive list of false assumptions developers take into the development of search.

Among the many believed falsehoods:

  • “Customers who know what they are looking for will search for it in the way you expect”
  • “You can write a query parser that will always parse the query successfully”
  • “Once setup, search will work the same way for the next week”
  • “Synonyms are easy”
  • … And many others gems — you should give it a read!

The takeaway is that search has many challenges — and they aren’t just under-the-hood. You need to think about how to manage state, build components for filtering, faceting, sorting, pagination, synonyms, language processing, and much, much… much more. But, in summary:

Building great search requires two sophisticated parts: (1) the search engine, which provides APIs to power search and (2) the search library, which paints the search experience.

For the search engine, we’ll look at Elastic App Search.

For the search experience, we’ll introduce an OS search library: Search UI.

When we’re done, it’ll lookjust like this:

Search Engine: Elastic App Search

App Search is available as either a paid, managed service, or a free, self-managed distribution. We’ll use the managed service for this tutorial, But remember that your team can use Search UI and App Search with a basic license at no cost if you host it yourself.

The plan: index documents which represent the best video games of all time into a search engine, then design and optimize a search experience to search through them.

First, signup for a 14 day trial — no credit card needed.

Create an Engine. You can pick from 13 different languages.

Let’s name it video-games and set the language to English.

Download the best video games data set and then upload it to App Search using the importer.

Next, click into the Engine, then select the Credentials tab.

Create a new Public Search Key with Limited Engine Access to only the video-games engine.

Retrieve the new Public Search Key and your Host Identifier.

Even though it didn’t look like much, we now have a fully functioning search engine that’s ready to search through our video game data using a refined search API.

Here’s what we’ve done so far:

  • Created a search engine.
  • Ingested documents.
  • Created a default schema.
  • Retrieved a scoped, disposable credential that we can expose to the browser.

That’s it for App Search, for now.

Let’s get to building our search experience using Search UI.

Search Library: Search UI

We’re going to use the [create-react-app](https://github.com/facebook/create-react-app) scaffolding utility to create a React app:

npm install -g create-react-app
create-react-app video-game-search --use-npm
cd video-game-search

Within this foundation, we’ll install Search UI and the App Search connector:

npm install — save @elastic/react-search-ui @elastic/search-ui-app-search-connector

And start the app in development mode:

npm start

Open up src/App.js in your favourite text editor.

We’ll start with some boilerplate code, and then unpack it.

Mind the comments!

// Step #1, import Statements
import React from "react";
import AppSearchAPIConnector from "@elastic/search-ui-app-search-connector";
import { SearchProvider, Results, SearchBox } from "@elastic/react-search-ui";
import { Layout } from "@elastic/react-search-ui-views";
import "@elastic/react-search-ui-views/lib/styles/styles.css";
// Step #2, The Connector
const connector = new AppSearchAPIConnector({
  searchKey: "[YOUR_SEARCH_KEY]",
  engineName: "video-games",
  hostIdentifier: "[YOUR_HOST_IDENTIFIER]"
});
// Step #3: Configuration Options
const configurationOptions = {
  apiConnector: connector
  // Let's fill this in together.
};
// Step #4, SearchProvider: The Finishing Touches.
export default function App() {
  return (
    <SearchProvider config={configurationOptions}>
      <div className="App">
        <Layout
        // Let's fill this in together.
        />
      </div>
    </SearchProvider>
  );
}
Step 1: import Statements

We’ll need to import our Search UI dependencies and React.

The core components, connector, and view components are contained within three different packages: @elastic/search-ui-app-search-connector, @elastic/react-search-ui, and @elastic/react-search-ui-views. We’ll learn more about each of them as we proceed.

import React from "react";
import AppSearchAPIConnector from "@elastic/search-ui-app-search-connector";
import { SearchProvider, Results, SearchBox } from "@elastic/react-search-ui";
import { Layout } from "@elastic/react-search-ui-views";
import "@elastic/react-search-ui-views/lib/styles/styles.css";

We’ll also be importing a default stylesheet for this project, which will give us a nice look and feel without writing a line of our own CSS:

import "@elastic/react-search-ui-views/lib/styles/styles.css";
Step 2: The Connector

We have our Public Search Key and Host Identifier from App Search.

Time to put them to work!

The connector object within Search UI uses the credentials to hook into App Search and power search:

const connector = new AppSearchAPIConnector({
  searchKey: "[YOUR_SEARCH_KEY]",
  engineName: "video-games",
  hostIdentifier: "[YOUR_HOST_IDENTIFIER]"
});

Search UI works with any search API. But connectors make it so that a search API will “just work”, without any deeper configuration.

Step 3: configurationOptions

Before we dig into configurationOptions, let’s take a moment to reflect.

We imported a set of data into our search engine. But what kind of data is it?

The more we know about our data, the better we’ll understand how to present that data to searchers. And that’ll inform how to configure the search experience.

Let’s look at one object, the best object of all within this data set:

{
  "id": "final-fantasy-vii-ps-1997",
  "name": "Final Fantasy VII",
  "year": 1997,
  "platform": "PS",
  "genre": "Role-Playing",
  "publisher": "Sony Computer Entertainment",
  "global_sales": 9.72,
  "critic_score": 92,
  "user_score": 9,
  "developer": "SquareSoft",
  "image_url": "https://r.hswstatic.com/w_907/gif/finalfantasyvii-MAIN.jpg"
}

We see that it has several text fields like name, year, platform, and so on and some number fields like critic_score, global_sales, and user_score.

If we ask three key questions, we’ll know enough to build a solid search experience:

  1. How will most people search? By the name of the video game.
  2. What will most people want to see in a result? The name of the video game, its genre, publisher, scores, and its platform.
  3. How will most people filter, sort, and facet? By score, genre, publisher, and platform.

We then can translate those answers into our configurationOptions:

const configurationOptions = {
  apiConnector: connector,
  searchQuery: {
    search_fields: {
      // 1. Search by name of video game.
      name: {}
    },
    // 2. Results: name of the video game, its genre, publisher, scores, and platform.
    result_fields: {
      name: {
        // A snippet means that matching search terms will be highlighted via <em> tags.
        snippet: {
          size: 75, // Limit the snippet to 75 characters.
          fallback: true // Fallback to a "raw" result.
        }
      },
      genre: {
        snippet: {
          size: 50,
          fallback: true
        }
      },
      publisher: {
        snippet: {
          size: 50,
          fallback: true
        }
      },
      critic_score: {
        // Scores are numeric, so we won't attempt to snippet these, we'll just use the raw
        // value.
        raw: {}
      },
      user_score: {
        raw: {}
      },
      platform: {
        snippet: {
          size: 50,
          fallback: true
        }
      },
      image_url: {
        raw: {}
      }
    },
    // 3. Facet by scores, genre, publisher, and platform, which we'll use to build filters later.
    facets: {
      user_score: {
        type: "range",
        ranges: [
          { from: 0, to: 5, name: "Not good" },
          { from: 5, to: 7, name: "Not bad" },
          { from: 7, to: 9, name: "Pretty good" },
          { from: 9, to: 10, name: "Must play!" }
        ]
      },
      critic_score: {
        type: "range",
        ranges: [
          { from: 0, to: 50, name: "Not good" },
          { from: 50, to: 70, name: "Not bad" },
          { from: 70, to: 90, name: "Pretty good" },
          { from: 90, to: 100, name: "Must play!" }
        ]
      },
      genre: { type: "value", size: 100 },
      publisher: { type: "value", size: 100 },
      platform: { type: "value", size: 100 }
    }
  }
};

We’ve connected Search UI to our search engine and now we have options that govern how we’re going to search through data, display our results, and then explore those results. But we need something to tie everything to the dynamic frontend components of Search UI.

Step 4: SearchProvider

The object that rules them all; the SearchProvider is where all other components are nested.

Search UI provides a Layout component, which is used to paint a typical search layout. There are deep customization options, but we won’t go into those in this tutorial.

We will do two things:

  1. Pass in configurationOptions to SearchProvider.
  2. Place some structural building blocks into Layout and add two basic components: SearchBox and Results.
export default function App() {
  return (
    <SearchProvider config={configurationOptions}>
      <div className="App">
        <Layout
          header={<SearchBox />}
          // titleField is the most prominent field within a result: the result header.
          bodyContent={<Results titleField="name" urlField="image_url" />}
        />
      </div>
    </SearchProvider>
  );
}

At this point, we have the basics set up on the front-end. There’s a few more details to work out on the back-end before we can run this. We should also work on the relevance model so that search is fine tuned for the unique needs of this project.

Off to App Search ~

Back to the Lab

App Search has powerful and refined search engine features. It makes once-sophisticated tuning much more enjoyable. We can perform fine-grained relevance adjustments and seamless schema changes in a few clicks.

We’ll adjust the schema first to see it in action.

Login to App Search, enter the video-games Engine, and then click Schema under the Manage section.

The schema appears. Each of the 11 fields is considered text by default.

In the configurationOptions object, we’ve defined two range facets to help us search through numbers: user_score and critic_score. For a range facet to work as expected, the field type needs to be a number.

We also might want to do some boosting and relevance tuning based on numerical values.

Click on the drop down menu next to each field, change it to number, then click Update Types:

The Engine re-indexes on the fly. And later on — when we add the faceting components to our layout — the range filters will function as we expect.

And now, onto the real nifty stuff.

This Section Is Highly Relevant

There are three key relevance features: Synonyms, Curations, and Relevance Tuning.

Select each feature under the Search Settings section in the sidebar:

Synonyms

Some people drive cars, some automobiles, others might drive a jalopy. The internet is global and people around the globe use different words to describe things. Synonyms help you create sets of terms that are considered one and the same.

In the case of a video game search engine, we know people will want to find Final Fantasy. But maybe they’ll type FF instead.

Click into Synonyms, then select Create a Synonym Set and enter the terms:

Click Save. You can add as many synonym sets as you’d like.

Searches for FF will now carry the same weight as searches for Final Fantasy.

Curations

Curations are a favorite. What if someone does search for Final Fantasy or FF? There are many games in the series — which will they get?

By default, the top five results looks like so:

  1. Final Fantasy VIII
  2. Final Fantasy X
  3. Final Fantasy Tactics
  4. Final Fantasy IX
  5. Final Fantasy XIII

That doesn’t seem right… Final Fantasy VII was the best Final Fantasy game of all. And Final Fantasy XIII wasn’t very good! 😜

Can we make it so that someone searching for Final Fantasy will receive Final Fantasy VII as the first result? And can we remove Final Fantasy XII from our search results?

We can!

Click into Curations and enter a query: Final Fantasy.

Next, drag the Final Fantasy VII document up to the Promoted Documents section by grabbing the handlebar on the leftmost side of the table. And then click on the Hide Result button on the Final Fantasy XIII document — the eye with the line going through it:

Anyone performing a search for Final Fantasy or FF will now see Final Fantasy VII first.

… And they won’t see Final Fantasy XIII. Hah!

We can promote and hide many documents. We can even sort promoted documents so we maintain full control over what appears at the top of each query.

Relevance Tuning

Click on Relevance Tuning in the sidebar.

We search into one text field: the name field. But what if we have multiple text fields people will search through, like a name field and a description field? The video game data set we’re using does not contain a description field, so we’ll fake some documents to think through it.

Say our documents looked similar to this:

{ 
  "name":"Magical Quest",
  "description": "A dangerous journey through caves and such." 
},
{ 
  "name":"Dangerous Quest",
  "description": "A magical journey filled with magical magic. Highly magic." 
}

If someone wanted to find the game Magical Quest, they would enter that as the query. But the first result would be Dangerous Quest:

Why? Because the word “magical” is present three times in the description of Dangerous Quest and the search engine will not know that one field is more important than another. It will then rank Dangerous Quest higher. This conundrum is why Relevance Tuning exists.

We can select a field and — among other things — increase the weighting of its relevance:

We see that when we scale up weight, the right item — Magical Quest — rises to the top because the name field becomes more significant. All we need to do is drag the slider to a higher value and click Save.

We’ve now used App Search to:

  1. Adjust the schema and change user_score and critic_score to number fields.
  2. Fine-tune the relevance model.

And that concludes the fancy “dashboard” features — each one has a matching API endpoint which you can use to make things work programmatically if GUIs aren’t your thing.

Now, let’s finish off the UI.

Finishing Touches

At this point your UI should be functional. Try some queries and poke around. The first thing that jumps out is that we’re missing tools to explore our results, like filtering, faceting, sorting, and so on, but search works. We’ll need to flesh out the UI.

Within the initial src/App.js file, we imported three basic components:

import { SearchProvider, Results, SearchBox } from "@elastic/react-search-ui";

Let’s add some more, given what we’ve defined for our configuration options.

Importing the following components will enable the missing abilities within the UI:

  • PagingInfo: Display information on the current page.
  • ResultsPerPage: Configure how many results appear on each page.
  • Paging: Navigate through different pages.
  • Facet: Filter and explore data in ways unique to the type of data.
  • Sorting: Re-orient results for a given field.
import {
  PagingInfo,
  ResultsPerPage,
  Paging,
  Facet,
  SearchProvider,
  Results,
  SearchBox,
  Sorting
} from "@elastic/react-search-ui";

Once imported, components can be placed into the Layout.

The Layout component divides the page into sections and components can be placed into these sections via props.

It contains sections for the:

  1. header: Search box/bar.
  2. bodyContent: Result container .
  3. sideContent: Sidebar which contains facets and sorting options.
  4. bodyHeader: “Wrapper” around results with context rich information like current page, number of results per page.
  5. bodyFooter: Paging options for quick navigation between pages.

Components render data. Data is fetched based on the search settings we provided in the configurationOptions. Now, we’ll place each component in the appropriate Layout section.

For example, we described 5 faceting dimensions in configurationOptions, so we’ll create 5 Facet components. Each Facet component will use a field prop as a key back to our data.

We’ll put them in the sideContent section, along with our Sorting component, then place the Paging, PagingInfo, ResultsPerPage components in the sections that best suites them:

<Layout
  header={<SearchBox />}
  bodyContent={<Results titleField="name" urlField="image_url" />}
  sideContent={
    <div>
      <Sorting
        label={"Sort by"}
        sortOptions={[
          {
            name: "Relevance",
            value: "",
            direction: ""
          },
          {
            name: "Name",
            value: "name",
            direction: "asc"
          }
        ]}
      />
      <Facet field="user_score" label="User Score" />
      <Facet field="critic_score" label="Critic Score" />
      <Facet field="genre" label="Genre" />
      <Facet field="publisher" label="Publisher" isFilterable={true} />
      <Facet field="platform" label="Platform" />
    </div>
  }
  bodyHeader={
    <>
      <PagingInfo />
      <ResultsPerPage />
    </>
  }
  bodyFooter={<Paging />}
/>

Now let’s have a look at the search experience in the local development environment.

Much better! We have rich options to explore the search results.

We threw in a couple extra goodies like multiple sort options and we’ve made the publisher facet filterable by adding a single flag. Try a search with a blank query and explore all the options.

Finally… let’s look at one last feature of the search experience. It’s a popular one…

Autocomplete.

You Autocomplete Me

Searchers love autocomplete because it provides instant feedback. Its suggestions come in two flavors: result and query. Depending on which flavor, a searcher will receive relevant results or potential queries that can lead to results.

We’re going to focus on autocomplete as a form of “query suggestion”.

This requires two quick changes.

First, we need to add autocomplete to the configurationOptions object:

const configurationOptions = {
  // ...
  autocompleteQuery: {
    suggestions: {
      types: {
        documents: {
          // Which fields to search for suggestions.
          fields: ["name"]
        },
        // How many suggestions appear.
        size: 5
      }
    }
  }
  // ...
};

Second, we need to enable autocomplete as a function of the SearchBox:

// ...
<Layout
  // ...
  header={<SearchBox autocompleteSuggestions={true} />}
/>
// ...

Yep — that’s it.

Try searching — as you type, autocomplete query suggestions appear.

Summary

We now have a good looking, functional search experience. And we’ve avoided a whole mess of pitfalls that often catch people as they try to implement search. Not bad for 30 minutes, wouldn’t you say?

Search UI is a flexible, modern React framework for the quick development of search experiences. Elastic App Search is a robust search engine built atop Elasticsearch. It’s a paid, managed service or you can run it yourself free with an ample basic license.
We’d love to see what you build with Search UI.
Stop by Gitter and consider contributing to the project!

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For those who don't know, I'm a full stack web developer who has been in the industry for over 5 years now. There is a lot of things I have learned along the way and I'd like to share that knowledge with anyone wanting to learn!

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🧠 Concepts Covered:

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Pagination in ReactJs

Pagination in ReactJs

There are a lot of resourceful materials online that give good insights into pagination in ReactJs, as well as NPM packages you can easily use

There are a lot of resourceful materials online that give good insights into pagination in ReactJs, as well as NPM packages you can easily use. As much as I appreciate those materials and love to use those packages, they mostly deal with loading the whole dataset on the page first then completely handle the pagination in the frontend. I am approaching this article with the concept of loading the exact data needed on the page, then manually loading other dataset based on the request when the user clicks the pagination number display. Below is the content structure to guide us through this article:

Table of Contents
  • Project Setup
  • HTML and CSS Styling
  • Pagination Data Format
  • Sample API request
  • Displaying the initial data
  • Showing Page Number and getting Other data
Project Setup

We are going to use create-react-app v0.1.0 which has the CSS Module configured already. Open your terminal and cd to the folder you want the project installed. Then run the below command:

npx create-react-app pagination  --use-npm

The above command will download the project into the folder calledpagination. You need to cd into the folder and run npm start. If everything goes well, you will have a page that looks like below:

HTML and CSS Styling

Open the project in your favorite code editor and locate the App.js file, We need to prepare our App.js to the look exactly like the way we want it by adding the HTML code and CSS style below:

Create a new file called App.module.css in the same directory where you have your App.js, then import it into your App.js using:

import styles from './App.module.css';

I want us to handle the display of the pagination number first, below is the style and HTML structure of what we are going to use.

  render() {
    

    return (
      <div className={styles.app}>
        
        <table className={styles.table}>
          <thead>
            <tr>
              <th>S/N</th>
              <th>First Name</th>
              <th>Last Name</th>
            </tr>
          </thead>
          <tbody>
              <tr>
                <td>1</td>
                <td>Abel</td>
                <td>Agoi</td>
              </tr>
              <tr>
                <td>2</td>
                <td>Muyiwa</td>
                <td>Aregbesola</td>
              </tr>
              <tr>
                <td>3</td>
                <td>Opeyemi</td>
                <td>Agoi</td>
              </tr>
              <tr>
                <td>4</td>
                <td>Ope</td>
                <td>Aina</td>
              </tr>
          </tbody>
        </table>


        <div className={styles.pagination}>
          <span>&laquo;</span>
          <span className={styles.active}>1</span>
          <span>2</span>
          <span>3</span>
          <span>4</span>
        </div>

      </div>
    );
  }

pagination_01.js

Add the content below into your App.module.css.

.app {
    width: 50%;
    margin: 0 auto;
}

table {
  border-collapse: collapse;
  border-spacing: 0; 
}


table {
  border-collapse: separate;
  border-spacing: 0;
  color: #4a4a4d;
  font: 14px/1.4 "Helvetica Neue", Helvetica, Arial, sans-serif;
  width: 100%;
}
tr {
  overflow-x: scroll;
}
th,
td {
  padding: 15px 15px;
  vertical-align: middle;
  /* text-align: left; */
}
thead {
  font-size: 14px;
  line-height: 24px;
  font-family: Lato;
  border: 1px solid transparent;

  max-width: 100%;
  font-weight: 900;
  line-height: 24px;
  mix-blend-mode: normal;

  color: rgba(51, 51, 51, .5);
  background: rgba(255, 255, 255, .9);
}
thead tr th {
  padding: 15px 15px;
  border: 1px solid transparent;


  text-align: left;
}
tbody {
  max-width: 100%;
}
tbody tr:nth-child(odd) {
  background: #f0f0f2;
}
tbody tr:hover {
  background: #f0f0f2;
}
td {
  padding: 15px 15px;
}
td:first-child {
}


.pagination {
    margin-top: 25px;
}
.pagination span {
  cursor: pointer;
  color: black;
  float: left;
  padding: 8px 16px;
  text-decoration: none;
  transition: background-color .3s;
  border: 1px solid #ddd;
}

.pagination span.active {
  background-color: #0099FF;
  color: white;
  border: 1px solid #0099FF;
}

pagination_app.module.css

Sorry for the plenty code written so far :), I want us to have a good looking table with pagination style in place before we move into the actual paging. If everything goes well, your view should look like below:

Pagination Data Format

In most cases, when you are making API calls to an endpoint that returns a paginated data, you need to pass at least the page number with the URL, hence a sample URL will look like below:

https://reqres.in/api/users?page=2

The most important thing to take note of in the URL above is the page=2 where 2 is the page number dataset we want to get. It can be 3,4 or any number as much as the dataset we have in the backend.

The response will always contain three important data which are per_page, total and the actual data we want to loop through. A sample response looks like below:

Sample API request

Talking about making an API request to the backend, We need a backend to make the request to, I decide to use https://reqres.in/ as the API endpoint for this tutorial because it is free, always available and reliable. You can decide to make your API request directly inside your component’s ComponentDidMount() or dispatch an action to redux from your ComponentDidMount() but for the purpose of this tutorial, we are going to make the API call from the App.js componentDidMount().

Firstly, we need to set the component’s state like below inside your App.js

  state = {
    users: null,
    total: null,
    per_page: null,
    current_page: null
  }

pagination_component_state.js

users is going to be the data we are going to loop over, while total and per_page is going to help us with calculating paging logic while the current_page will be used to style the active pagination link.

The next thing we should do is create a helper method that will serve the purpose of making an HTTP request to the API endpoint and also update the state with the response data. The method will look like below:

  makeHttpRequestWithPage = async pageNumber => {
    let response = await fetch(`https://reqres.in/api/users?page=${pageNumber}`, {
      method: 'GET',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
    });

    const data = await response.json();

    this.setState({
      users: data.data,
      total: data.total,
      per_page: data.per_page,
      current_page: data.page,
    });
  }

pagination_http_request.js

This method will accept a parameter called pageNumber so it can be reusable and will always update the state with the right data when the response is successful.

Since on page load, we need to make the HTTP request to the backend, and we are going to do this inside thecomponentDidMount() by calling the method above and passing it the first-page number we want which should be 1. Hence, the componentDidMount() will look like below:

 componentDidMount() {
    this.makeHttpRequestWithPage(1);
  }

pagination_componentDidMount.js

If we add console.dir(this.state.users) inside the render() method, below will be printed in the console

The null was before the data arrived, once the data arrived, it updates the state, hence the array of users data.

Displaying the initial data

Haven gotten the data needed, we need to loop through the data and display it. Hence we can update our render method to have below:

    let users;

    if (this.state.users !== null) {
      users = this.state.users.map(user => (
        <tr key={user.id}>
          <td>{user.id}</td>
          <td>{user.first_name}</td>
          <td>{user.last_name}</td>
        </tr>
      )); 
    }
    
    return (
      <div className={styles.app}>
        
        <table className={styles.table}>
          <thead>
            <tr>
              <th>S/N</th>
              <th>First Name</th>
              <th>Last Name</th>
            </tr>
          </thead>
          <tbody>
              { users }
          </tbody>
        </table>


        <div className={styles.pagination}>
          <span>&laquo;</span>
          <span className={styles.active}>1</span>
          <span>2</span>
          <span>3</span>
          <span>4</span>
          <span>&raquo;</span>
        </div>

      </div>
    );

gistfile1.txt

I replaced the dummy data we had inside the with the result of the loop which I equated to users. We have the assurance that when the state changes, ReactJs will automatically update the content of the table. The final stage is displaying the page logic and getting the other contents based on the page number clicked which will be sent to the API endpoint.

Showing Page Number and getting other data

Before we talk about showing page number automatically using the desired logic, I want us to manually show those numbers and make the actual API calls when the numbers are clicked. For now, we are going to hard code the pagination numbers ourselves like below:

<div className={styles.pagination}>
  <span onClick={() => this.makeHttpRequestWithPage(1)}>1</span>
  <span onClick={() => this.makeHttpRequestWithPage(2)}>2</span>
  <span onClick={() => this.makeHttpRequestWithPage(3)}>3</span>
  <span onClick={() => this.makeHttpRequestWithPage(4)}>4</span>
</div>

pagination_hard_code.js

The above code will look like below when previewed in the browser.

Notice that each span has an event handler attached to it, and I passed the page number to that event handler, so anytime we click on the pagination link, it will make a new HTTP request and update the component states, hence the user’s table data. We do not want to hard-code the links as we did above, so we need to automatically display those links.

So we’re planning on showing the page numbers for a series of pieces of data so that users can easily navigate multiple items. There are a few things that we need to know first:

  • The page that we’re on
  • Total number of items
  • Number of items per page

Good news is that we have captured all these things in our component’s state.

Next, we need to look at how we want to display the page numbers, there is a wide range of methods that people use:

  • Simple Next/Previous buttons with no numbers
  • A list of all possible pages
  • Page 1 & the last page, with the current page (and 2 above/below) shown

I personally prefer to show the very first page, that last page, and then the current page with 2 pages above & below. So for example on page 12 out of 24 pages we’d see:

1, 10, 11, 12, 13, 14, 24

This allows users to quickly navigate to the start, and to the end, as well as jump through multiple pages at once. For the purpose of this tutorial, I am going to show us how to show a list of all possible pages(item two above) then item three too.

The Arithmetic

We need to work out the total number of pages, for this, we want to take the total number of items that there are, and divide it by the number of items per page. But we want to make sure that we take that number and round it up.

So if there were 12 items in total, and we were showing 5 per page, we’d have a total of 3 pages of items. If we were to show 3 per page, we’d show 4 pages.

const pageNumbers = [];
for (let i = 1; i <= Math.ceil(this.state.meta.total / this.state.meta.per_page); i++) {
    pageNumbers.push(i);
}

page_logic_pagination.js

Haven gotten the page numbers, we need to loop through to display the span since we want to show all possible numbers first, our loop will look like below:

renderPageNumbers = pageNumbers.map(number => {
  let classes = this.state.current_page === number ? styles.active : '';

  return (
    <span key={number} className={classes} onClick={() => this.makeHttpRequestWithPage(number)}>{number}</span>
  );
});

pagination_all_numbers_loop.js

We need to update our pagination view to look like below:

<div className={styles.pagination}>
  <span onClick={() => this.makeHttpRequestWithPage(1)}>&laquo;</span>
  {renderPageNumbers}
</div>

pagination_view._01js

Congrats, we have successfully handle pagination, make HTTP request to the backend and changing the table content when user click on the page number to see.

To be sure we are on the same page, my App.js code looks like below:

import React, { Component } from 'react';
import styles from './App.module.css';

class App extends Component {


  state = {
    users: null,
    total: null,
    per_page: null,
    current_page: 1
  }


  componentDidMount() {
    this.makeHttpRequestWithPage(1);
  }


  makeHttpRequestWithPage = async pageNumber => {
    const response = await fetch(`https://reqres.in/api/users?page=${pageNumber}`, {
      method: 'GET',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
    });

    const data = await response.json();

    this.setState({
      users: data.data,
      total: data.total,
      per_page: data.per_page,
      current_page: data.page
    });
  }


  render() {

    let users, renderPageNumbers;

    if (this.state.users !== null) {
      users = this.state.users.map(user => (
        <tr key={user.id}>
          <td>{user.id}</td>
          <td>{user.first_name}</td>
          <td>{user.last_name}</td>
        </tr>
      ));
    }

    const pageNumbers = [];
    if (this.state.total !== null) {
      for (let i = 1; i <= Math.ceil(this.state.total / this.state.per_page); i++) {
        pageNumbers.push(i);
      }


      renderPageNumbers = pageNumbers.map(number => {
        let classes = this.state.current_page === number ? styles.active : '';

        return (
          <span key={number} className={classes} onClick={() => this.makeHttpRequestWithPage(number)}>{number}</span>
        );
      });
    }

    return (


      <div className={styles.app}>

        <table className={styles.table}>
          <thead>
            <tr>
              <th>S/N</th>
              <th>First Name</th>
              <th>Last Name</th>
            </tr>
          </thead>
          <tbody>
            {users}
          </tbody>
        </table>


        <div className={styles.pagination}>
          <span onClick={() => this.makeHttpRequestWithPage(1)}>&laquo;</span>
          {renderPageNumbers}
          <span onClick={() => this.makeHttpRequestWithPage(1)}>&raquo;</span>
        </div>

      </div>
    );
  }

}

export default App;

pagination_app.js

and my view like below:

We can change the page number display logic to below since it will accommodate for large dataset.

renderPageNumbers = pageNumbers.map(number => {
  let classes = this.state.current_page === number ? styles.active : '';

  if (number == 1 || number == this.state.total || (number >= this.state.current_page - 2 && number <= this.state.current_page + 2)) {
    return (
      <span key={number} className={classes} onClick={() => this.makeHttpRequestWithPage(number)}>{number}</span>
    );
  }
});

pagination_another_display_logic.js

Thanks for reading.