Morioh
Login
Elvis Miranda

Elvis Miranda

5 years ago

Other versions available:

This is a simple example of how to implement server-side pagination in Vue.js with a Node.js backend API.

The example contains a hard coded array of 150 objects split into 30 pages (5 items per page) to demonstrate how the pagination logic works. Styling of the example is done with Bootstap 4.

The tutorial code is available on GitHub at https://github.com/cornflourblue/vue-node-server-side-pagination.

Here it is in action (may take a few seconds for the container to startup):

Running the Vue.js + Node Pagination Example Locally

  1. Install NodeJS and NPM from https://nodejs.org.
  2. Download or clone the tutorial project source code from https://github.com/cornflourblue/vue-node-server-side-pagination.
  3. Install required npm packages of the backend Node API by running the npm install command in the /server folder.
  4. Start the backend Node API by running npm start in the /server folder, this will start the API on the URL http://localhost:4000.
  5. Install required npm packages of the frontend Vue.js app by running the npm install command in the /client folder.
  6. Start the Vue.js frontend app by running npm start in the /client folder, this will build the app with webpack and automatically launch it in a browser on the URL http://localhost:8080.

Server-Side (Node.js) Pagination Logic

Pagination is handled by the backend Node API with the help of the jw-paginate npm package, for more info on how the pagination logic works see JavaScript - Pure Pagination Logic in Vanilla JS / TypeScript.

Below is the code for the paged items route (/api/items) in the node server file (/server/server.js) in the example, it creates a hardcoded list of 150 items to be paged, in a real application you would replace this with real data (e.g. from a database). The route accepts an optional page parameter in the url query string, if the parameter isn’t set it defaults to the first page.

The paginate() function is from the jw-paginate package and accepts the following parameters:

The output of the paginate function is a pager object containing all the information needed to get the current pageOfItems out of the itemsarray, and to display the pagination controls in the Vue.js frontend, including:

I’ve set the pageSize to 5 in the CodeSandbox example above so the pagination links aren’t hidden below the terminal console when the container starts up. In the code on GitHub I didn’t set the page size so the default 10 items are displayed per page in that version.

The current pageOfItems is extracted from the items array using the startIndex and endIndex from the pager object. The route then returns the pager object and current page of items in a JSON response.

// paged items route
app.get('/api/items', (req, res, next) => {
    // example array of 150 items to be paged
    const items = [...Array(150).keys()].map(i => ({ id: (i + 1), name: 'Item ' + (i + 1) }));

    // get page from query params or default to first page
    const page = parseInt(req.query.page) || 1;

    // get pager object for specified page
    const pageSize = 5;
    const pager = paginate(items.length, page, pageSize);

    // get page of items from items array
    const pageOfItems = items.slice(pager.startIndex, pager.endIndex + 1);

    // return pager object and current page of items
    return res.json({ pager, pageOfItems });
});

Client-Side (Vue.js) Pagination Component

Since the pagination logic is handled on the server, the only thing the Vue.js client needs to do is fetch the pager information and current page of items from the backend, and display them to the user.

Vue.js Home Page Component

Below is the Vue home page component (/client/src/home/HomePage.vue) from the example. The template renders the current page of items as a list of divs with the v-for directive, and renders the pagination controls using the data from the pager object. Each pagination link sets the page query parameter in the url with the <router-link> component and :to="{ query: { page: ... }}" property.

The Vue component contains a watcher function on the page url query parameter '$route.query.page', the handler function is triggered by Vue whenever the page variable in the url querystring changes, the immediate: true flag tells Vue to also run the function when the component first loads. The watcher function checks if the page has changed and fetches the pager object and pageOfItems for the current page from the backend API with an HTTP request.

The CSS classes used are all part of Bootstrap 4.3, for more info see https://getbootstrap.com/docs/4.3/getting-started/introduction/.

<template>
    <div class="card text-center m-3">
        <h3 class="card-header">Vue.js + Node - Server Side Pagination Example</h3>
        <div class="card-body">
            <div v-for="item in pageOfItems" :key="item.id">{{item.name}}</div>
        </div>
        <div class="card-footer pb-0 pt-3">
            <ul v-if="pager.pages && pager.pages.length" class="pagination">
                <li :class="{'disabled':pager.currentPage === 1}" class="page-item first-item">
                    <router-link :to="{ query: { page: 1 }}" class="page-link">First</router-link>
                </li>
                <li :class="{'disabled':pager.currentPage === 1}" class="page-item previous-item">
                    <router-link :to="{ query: { page: pager.currentPage - 1 }}" class="page-link">Previous</router-link>
                </li>
                <li v-for="page in pager.pages" :key="page" :class="{'active':pager.currentPage === page}" class="page-item number-item">
                    <router-link :to="{ query: { page: page }}" class="page-link">{{page}}</router-link>
                </li>
                <li :class="{'disabled':pager.currentPage === pager.totalPages}" class="page-item next-item">
                    <router-link :to="{ query: { page: pager.currentPage + 1 }}" class="page-link">Next</router-link>
                </li>
                <li :class="{'disabled':pager.currentPage === pager.totalPages}" class="page-item last-item">
                    <router-link :to="{ query: { page: pager.totalPages }}" class="page-link">Last</router-link>
                </li>
            </ul>
        </div>
    </div>
</template>

<script>
export default {
    data () {
        return {
            pager: {},
            pageOfItems: []
        }
    },
    watch: {
        '$route.query.page': {
            immediate: true,
            handler(page) {
                page = parseInt(page) || 1;
                if (page !== this.pager.currentPage) {
                    fetch(`/api/items?page=${page}`, { method: 'GET' })
                        .then(response => response.json())
                        .then(({pager, pageOfItems}) => {
                            this.pager = pager;
                            this.pageOfItems = pageOfItems;
                        });
                }
            }
        }
    }
}
</script>

Further reading:

☞ Docker & Nodejs: Aplicación de Nodejs en Docker Container

☞ Node.js file streams explained!

☞ 20. Node.js Lessons. Data Streams in Node.JS, fs.ReadStream

☞ How to create your first program with the Node.js runtime

☞ How to Build Simple Authentication in Express

#vue-js #node-js #javascript

Server Side Pagination with Vue.js and Node

jasonwatmore.com

Server Side Pagination with Vue.js and Node

Vue.js + Node - Server Side Pagination Tutorial & Example. A simple example of how to implement server-side pagination in Vue.js with a Node.js backend API.

84.10 GEEK