pjax with normal fallback!

pushState, hash-navigation, ajax forms, interchangeable url formats and other remarkable features

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What is it now?

It'a a fork of defunkt's pjax library: https://github.com/defunkt/jquery-pjax . That was completely awesome, but my project needed old IEs support. So I modified it a bit. I hope, you'll enjoy mix of pushState and regular #!/hash navigation.

Some features and changes:

• IE7+, FF4+ and all modern browsers (if it works on some not mentioned ancient browser – please let me know [email protected])
• mix of html5-like navigation and old-school #!/hashes
• i added most of ';' in lines of code for you :]. for some reason, defunkt didn't use them, but it was strange for me
• links from both kinds of browsers are interchangable

Some bad news:

• you HAVE to put some settings before using:

$.hash = '#!/';
$.siteurl = 'http://yoursite.com';
$.container = '#pjaxcontainer';

$.hash is a string, which appeares is url, when browser doesn't support pushState. So, by default, url of page changes from http://yoursite.com/this/is/awesome/article to http://yoursite.com/#!/this/is/awesome/article and pjax sends request to server with first url.

Links are interchangable – so if someone with modern browser gets old-style link http://yoursite.com/#!/page – he would be redirected to http://yoursite.com/page and vice versa.

And what about SEO?

All we know, most part of AJAX-enabled sites have issues with search engine crawlers – their links are basically not parsable because of #. But we can handle it at least with Google!

Default $.hash value is meaningful and hopely would be parsed in future by all major search engine crawlers. All you need – set up some custom routing on your server: if crawler meets link like http://yoursite.com/#!/some/path/on/site, he sends request to http://yoursite.com/?_escaped_fragment_=/some/path/on/site and parses it.

For more information:

• http://googlewebmastercentral.blogspot.com/2009/10/proposal-for-making-ajax-crawlable.html
• http://code.google.com/intl/ru-RU/web/ajaxcrawling/docs/specification.html

What was it?

Pjax loads HTML from your server into the current page without a full reload. It's ajax with real permalinks, page titles, and a working back button that fully degrades.

Pjax enhances the browsing experience - nothing more.

You can find a demo on http://pjax.heroku.com/

three ways to pjax on the client side:

One. Functionally obtrusive, loading the href with ajax into data-pjax:

<a href='/explore' data-pjax='#main'>Explore</a>

$('a[data-pjax]').pjax()

Two. Slightly obtrusive, passing a container and jQuery ajax options:

<a href='/explore' class='js-pjax'>Explore</a>

$('.js-pjax').pjax('#main', { timeout: null, error: function(xhr, err){
  $('.error').text('Something went wrong: ' + err)
}})

Three. Unobtrusive, showing a 'loading' spinner:

<div id='main'>
  <div class='loader' style='display:none'><img src='spin.gif'></div>
  <div class='tabs'>
    <a href='/explore'>Explore</a>
    <a href='/help'>Help</a>
  </div>
</div>

$('a').pjax('#main').live('click', function(){
  $(this).showLoader()
})

$(link).pjax( container, options )

The $(link).pjax() function accepts a container, an options object, or both. The container MUST be a string selector - this is because we cannot persist jQuery objects using the History API between page loads.

The options are the same as jQuery's $.ajax options with the following additions:

• container - The String selector of the container to load the reponse body. Must be a String.
• clickedElement - The element that was clicked to start the pjax call.
• push - Whether to pushState the URL. Default: true (of course)
• replace - Whether to replaceState the URL. Default: false
• error - By default this callback reloads the target page once timeout ms elapses.
• timeout - pjax sets this low, <1s. Set this higher if using a custom error handler. It's ms, so something like timeout: 2000
• fragment - A String selector that specifies a sub-element to be pulled out of the response HTML and inserted into the container. Useful if the server always returns full HTML pages.

$(form).pjaxform( container, options )

Same as $(link).pjax() but for forms. For GET forms will change address string

$.pjax( options )

You can also just call $.pjax directly. It acts much like $.ajax, even returning the same thing and accepting the same options.

The pjax-specific keys listed in the $(link).pjax() section work here as well.

This pjax call:

$.pjax({
  url: '/authors',
  container: '#main'
})

Roughly translates into this ajax call:

$.ajax({
  url: '/authors',
  dataType: 'html',
  beforeSend: function(xhr){
    xhr.setRequestHeader('X-PJAX', 'true')
  },
  success: function(data){
    $('#main').html(data)
    history.pushState(null, $(data).filter('title').text(), '/authors')
  })
})

pjax on the server side

You'll want to give pjax requests a 'chrome-less' version of your page. That is, the page without any layout.

As you can see in the "ajax call" example above, pjax sets a custom 'X-PJAX' header to 'true' when it makes an ajax request to make detecting it easy.

This is for PHP:

if (!isset($_SERVER['HTTP_X_PJAX'])
{
   // here is regular-kind load
}
else
{
   // here you don't print page layout — just the page
}

In Rails, check for request.headers['X-PJAX']:

def my_page
  if request.headers['X-PJAX']
    render :layout => false
  end
end

One more Rails example by slayerhabr (http://slayerhabr.habrahabr.ru/)

class ApplicationController < ActionController::Base
   layout Proc.new { |controller| request.headers['X-PJAX'] ? false : 'application' }
end

Django: https://github.com/jacobian/django-pjax

Asp.Net MVC3: http://biasecurities.com/blog/2011/using-pjax-with-asp-net-mvc3/

page titles

Your HTML should also include a <title> tag if you want page titles to work.

events

pjax will fire four events on the container you've asked it to load your reponse body into:

• start.pjax - Fired when a pjax ajax request begins.
• success.pjax - Fired on pjax ajax request success.
• complete.pjax - Fired on pjax ajax request complete, one parameter is jqXHR.
• error.pjax - Fired on pjax ajax request fail.

This allows you to, say, display a loading indicator upon pjaxing:

$('a.pjax').pjax('#main')
$('#main')
  .bind('start.pjax', function() { $('#loading').show() })
  .bind('success.pjax',   function() { $('#loading').hide() })
  .live('complete.pjax',   function(event, jqXHR) {  })
  .bind('error.pjax',   function() { })

Because these events bubble, you can also set them on the body:

$('a.pjax').pjax()
$('body')
  .bind('start.pjax', function() { $('#loading').show() })
  .bind('end.pjax',   function() { $('#loading').hide() })

browser support

Pjax works with browses that support the history.pushState API and old-ones, that don't. For the lasts we use hashes.

For a history API's table of supported browsers see: http://caniuse.com/#search=pushstate

To check if pjax is supported, use the $.support.pjax boolean.

When history API is not supported, $('a').pjax() calls will do use $.ajax to load page and window.location.hash to identify itself. On page load without history API script loads page due to hash.

install it

Download

Then, in your HTML:

<script src="path/to/js/jquery.pjax.js"></script>

Replace path/to/js with the path to your JavaScript directory, e.g. public/javascripts.