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Awesome Open Source


Pjax enables fast and easy AJAX navigation on any website using pushState and fetch. No more full page reloads, no more multiple HTTP request, and written entirely in TypeScript.


Download Pjax via NPM:

npm i --save @pageworks/pjax

Once the package is installed import the package:

import Pjax from '@pageworks/pjax';

Then it's as simple as starting a new instance:

new Pjax();

How Pjax Works

Pjax loads pages using the Fetch API and updates the browser's current URL using a window.pushState() all without reloading the page's layout or any resources (JavaScript, CSS, etc). Pjax listens for the onmouseenter event for links and prefetches the pages HTML. Dpending on what the user does determines Pjax's response. If the user clicks the link before the server responds Pjax will notice that the user wants the page and will switch out the content as soon as the server responds. Finally, if the user remains hovered and the server has already responded Pjax will cache the new pages HTML content and will wait until the user clicks the link or triggers the onmouseleave event causing Pjax to clear the cached HTML. When combining prefetching and the ability to swap out content without causing a full page reload results in very fast page load responses.

Under the hood Pjax is one HTTP request with a window.pushState().

What Pjax's All About

  • Multiple container support
  • Fully supports browser history (window popstates)
  • Automagically falls back to standard navigation for external pages
  • Automagically falls back to standard navigation for internal pages that do not have an appropriate DOM tree
  • Allows for modern CSS page transitions (animation) easily
  • Is very lightweight

Under the Hood

  • Pjax attempts to prefetch internal links for the fastest possible load time
  • Pjax renders new pages without reloading resources such as images, CSS, JavaScript, etc...
  • Checks that all defined parts can be replaced:
    • If the page doesn't meet the requirements Pjax will do nothing and standard navigation is used
    • If the page meets requirements Pjax swaps the DOM elements
  • Pjax updates the browser's current URL using pushState()


Getting Started

Start by setting up the basic index.html file for your website.

<!doctype <!DOCTYPE html>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Index | Pjax Testing</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <a href="index">Home</a>
    <main class="js-pjax-wrapper">
        <article class="js-pjax">
            <h1>Index Page</h1>
                <li><a href="index">Index</a></li>
                <li><a href="page-1">Page 1</a></li>
    <script src="main.js"></script>

In the main/application script for your project you can being using Pjax with the following:

import Pjax from '@pageworks/pjax';

const pjax = new Pjax({
    debug: true

Pjax Options

You can define custom Pjax options using the following:

Option Type Default
elements string a[href]
selectors string[] .js-pjax
history boolean true
cacheBust boolean false
debug boolean false
titleSwitch boolean true
customTransitions boolean false
customPreventionAttributes string[] []
importScripts boolean true
importCSS boolean true
scriptImportLocation HTMLElement document.head
requireCssBeforeComplete boolean false

elements is the base element users should click on to trigger a page transition.

selectors is an array of containers that Pjax should swap.

When history is true Pjax will use window.history.pushState() to manipulate the browsers history.

cacheBust will add a GET param to all request forcing the browser to perform the request instead of using a cached version of the page.

debug will tell Pjax to display all debug information.

titleSwitch when true will swap out the documents title during page transitions.

customTransitions when true Pjax won't actually switch out the content until the developers application sends a custom pjax:continue event.

customPreventionAttributes is an array of custom element attributes that Pjax will look for when attaching event listeners. The default prevention attribute that is prevent-pjax however you can define additional attributes. For example, if you are using a custom lightcase modal libary you could tell Pjax not to hijack the events attached to any element that has a valid href attribute when the element also has a lightcase attribute.

When importScripts is true Pjax will dynamically fetch and append all <script> elements. Elements with a valid src will be appended once, elements that contain JavaScript will be re-appended every time.

When importCSS is true Pjax will dynamically fetch and append custom <style> elements to the documents <head>. Only <link> elements labeled as rel="stylesheet" with a valid href attribute will be appended. Custom styles will only be appended once.

scriptImportLocation is the HTMLElement that the dynamically fetched <script> elements will be appended upon. Defaults to document.head.

When requireCssBeforeComplete is true Pjax will delay firing the pjax:complete event until all the CSS fetch request have been resolved.

Pjax Events

Pjax fires a handful of events on the document that you can listen for.

document.addEventListener('pjax:error', ()=>{ console.log('Event: pjax:error'); });
document.addEventListener('pjax:send', (e)=>{ console.log('Event: pjax:send', e); });
document.addEventListener('pjax:prefetch', ()=>{ console.log('Event: pjax:prefetch'); });
document.addEventListener('pjax:cancel', ()=>{ console.log('Event: pjax:cancel'); });
document.addEventListener('pjax:complete', ()=>{ console.log('Event: pjax:complete'); });
document.addEventListener('pjax:scriptContentLoaded', ()=>{ console.log('Event: pjax:scriptContentLoaded'); });

Pjax listens for a pjax:continue event on the document. This is only used when the customTransitions option is set to true. Pjax will NOT swap content until it receives this event.

The pjax:scriptContentLoaded will fire on the document when all the new scripts have been fetched and appended to the body.

Status Classes

Pjax sets two custom status classes on the document element that you can use in your CSS to style your page transitions. In the example below we set all elements to use the wait cursor while the dom-is-loading class is set. Once the pjax:complete or pjax:error events fire the dom-is-loading class is removed and the dom-is-loaded class is applied.

HTML.dom-is-loading *
    cursor: wait !important;

Static Methods

Pjax allows developers to manually trigger a page load by using the public static method Pjax.load(url)

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