pace
Include pace.js and the theme css of your choice on your page (as early as is possible), and you're done!
Pace will automatically monitor your ajax requests, event loop lag, document ready state, and elements on your page to decide the progress. On ajax navigation it will begin again!
If you use AMD or Browserify, require in pace.js and call pace.start()
as early in
the loading process as is possible.
Install with Eager
The easiest way to add Pace to your site is with Eager. Click Install to see a live preview of Pace on your website.
Example
<head>
<script src="/pace/pace.js"></script>
<link href="/pace/themes/pace-theme-barber-shop.css" rel="stylesheet" />
</head>
Configuration
Pace is fully automatic, no configuration is necessary to get started.
If you would like to make some tweaks, here's how:
You can set window.paceOptions
before bringing in the file:
paceOptions = {
// Disable the 'elements' source
elements: false,
// Only show the progress on regular and ajax-y page navigation,
// not every request
restartOnRequestAfter: false
}
You can also put options on the script tag:
<script data-pace-options='{ "ajax": false }' src='pace.js'></script>
If you're using AMD or Browserify, you can pass your options to start
:
define(['pace'], function(pace){
pace.start({
document: false
});
});
Themes
Pace includes a bunch of themes to get you started. Just include the appropriate css file. Send us a PR with any interesting themes you create.
Collectors
Collectors are the bits of code which gather progress information. Pace includes four default collectors:
Ajax
Monitors all ajax requests on the page
Elements
Checks for the existance of specific elements on the page
Document
Checks the document readyState
Event Lag
Checks for event loop lag signaling that javascript is being executed
They can each be configured or disabled through configuration options of the same name.
paceOptions = {
ajax: false, // disabled
document: false, // disabled
eventLag: false, // disabled
elements: {
selectors: ['.my-page']
}
};
Add your own classes to paceOptions.extraSources
to add more sources.
Each source should either
have a .progress
property, or a .elements
property which
is a list of objects with
.progress
properties. Pace will automatically handle all scaling to
make the progress
changes look smooth to the user.
Elements
Elements being rendered to the screen is one way for us to decide that the page has been rendered. If you would like to use that source of information (not required at all), specify one or more selectors. You can comma seperate the selectors to propertly handle error states, where the progress bar should disappear, but the element we are looking for may never appear:
paceOptions = {
elements: {
selectors: ['.timeline,.timeline-error', '.user-profile,.profile-error']
}
}
Pace will consider the elements test successful when each selector matches something.
For
this example, when either .timeline
or .timeline-error
exist, and either .user-profile
or .profile-error
exist.
Restart Rules
Most users want the progress bar to automatically restart when a pushState event occurs (generally means ajax navigation is occuring). You can disable this:
paceOptions = {
restartOnPushState: false
}
You can also have pace restart on every ajax request which lasts longer than x ms. You'll want to disable this if you make ajax requests the user doesn't need to know about, like precaching:
paceOptions = {
restartOnRequestAfter: false
}
You can always trigger a restart manually by calling Pace.restart()
See the source for a full list of all options.
API
Pace exposes the following methods:
Pace.start
: Show the progress bar and start updating. Called automatically if you don't use AMD or CommonJS.Pace.restart
: Show the progress bar if it's hidden and start reporting the progress from scratch. Called automatically wheneverpushState
orreplaceState
is called by default.Pace.stop
: Hide the progress bar and stop updating it.Pace.track
: Explicitly track one or more requests, see Tracking belowPace.ignore
: Expliticly ignore one or more requests, see Tracking below
Events
Pace fires the following events:
start
: When pace is initially started, or as a part of a restartstop
: When pace is manually stopped, or as a part of a restartrestart
: When pace is restarted (manually, or by a new AJAX request)done
: When pace is finishedhide
: When the pace is hidden (can be later thandone
, based onghostTime
andminTime
)
You can bind onto events using the on
, off
and
once
methods:
Pace.on(event, handler, [context])
: Callhandler
(optionally with context) whenevent
is triggeredPace.off(event, [handler])
: Unbind the providedevent
andhandler
combination.Pace.once(event, handler, [context])
: Bindhandler
to the next (and only the next) incidence ofevent
Tracking
By default, Pace will show any ajax requests which begin as a part of a normal or ajax-y page load, or which last longer than 500ms.
You can disable all ajax tracking by setting ajax
to false:
Pace.options = {
ajax: false
}
You can disable ajax tracking except on page navigation by setting restartOnRequestAfter
to false:
Pace.options = {
restartOnRequestAfter: false
}
You can manually disable tracking for a specific request or requests by triggering
them within a Pace.ignore
callback:
Pace.ignore(function(){
$.ajax(...)
});
You can force the progress bar to be shown for a specific request by triggering them
within a Pace.track
callback:
Pace.track(function(){
$.ajax(...)
});
You can also ignore URLs based on a pattern:
Pace.options = {
ajax: {
ignoreURLs: ['some-substring', /some-regexp/]
}
}
Dependencies
None!
Support
Pace is designed to support IE8+ (standards mode), FF 3.5+, Chrome, Safari 4+, Opera 10.5+, and all modern mobile browsers. If you run into a compatibility issue, or can make a case for supporting something else, please create an issue.
Size
pace.js is 4kb minified and gzipped. The themes vary between 0.5 and 4kb.
Issues
We have obviously not tested this on every website. If you run into an issue, or find a way the automatic detection could be better, please create an Issue. If you can include a test case, that's even better.
Contributing
PRs Welcome!
Building requires node.js.
npm install
grunt
You can also run grunt watch
to have it automatically build as you make
changes.
There is no need to include compiled files in PRs.
Credits
Javascript by Zack Bloom CSS by Adam Schwartz
Themes inspired by Mary Lou
Project inspired by nprogress