pjax = pushState + ajax

pjax是一个jQuery插件，它使用ajax和pushState为永久链接，页面标题和工作返回按钮提供快速浏览体验。
pjax的工作原理是通过ajax从服务器获取HTML片段，再替换原容器元素内容。
然后用pushState更新浏览器中的当前URL。
这么做出于以下两个原因：

• 没有页面资源（如：js css）被重新执行或请求；
• 如果服务器配置为pjax，就只是渲染局部而避免了全局渲染

这个项目的状态

jquery-pjax is largely unmaintained at this point. It might continue to
receive important bug fixes, but its feature set is frozen and it's unlikely
that it will get new features or enhancements.

jquery-pjax在很大程度上是无法维护的。 它可能会继续接收重要的错误修复，但是它的功能集是冻结状态的，而且不太可能会得到新的功能或增强。

安装

pjax依赖于jQuery 1.8或更高版本。

npm

$ npm install jquery-pjax

独立脚本

下载并在您的网页中包含jquery.pjax.js：

curl -LO https://raw.github.com/defunkt/jquery-pjax/master/jquery.pjax.js

用法

$.fn.pjax

pjax的最简单和最常见的用法是这样的：

$(document).pjax('a', '#pjax-container')

这将启用页面上所有链接的pjax，并将容器指定为＃pjax-container。

If you are migrating an existing site, you probably don't want to enable pjax
everywhere just yet. Instead of using a global selector like a, try annotating
pjaxable links with data-pjax, then use 'a[data-pjax]' as your selector. Or,
try this selector that matches any <a data-pjax href=> links inside a <div data-pjax> container:
如果您正在迁移现有网站，则可能不希望到处都启用pjax。 不要使用像“a”这样的全局选择器，可以将需要的链接添加为data-pjax，然后使用'a[data-pjax]' 作为选择器。
要么，试试下面这个选择器，它匹配任何 在一个 <div data-pjax>容器内部的<a data-pjax href=>链接：

$(document).pjax('[data-pjax] a, a[data-pjax]', '#pjax-container')

服务端配置

Ideally, your server should detect pjax requests by looking at the special
X-PJAX HTTP header, and render only the HTML meant to replace the contents of
the container element (#pjax-container in our example) without the rest of
the page layout. Here is an example of how this might be done in Ruby on Rails:

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

If you'd like a more automatic solution than pjax for Rails check out Turbolinks.

Check if there is a pjax plugin for your favorite server framework.

Also check out RailsCasts #294: Playing with PJAX.

Arguments

The synopsis for the $.fn.pjax function is:

$(document).pjax(selector, [container], options)

1. selector is a string to be used for click event delegation.
2. container is a string selector that uniquely identifies the pjax container.
3. options is an object with keys described below.

pjax options

key	default	description
timeout	650	ajax timeout in milliseconds after which a full refresh is forced
push	true	use pushState to add a browser history entry upon navigation
replace	false	replace URL without adding browser history entry
maxCacheLength	20	maximum cache size for previous container contents
version		a string or function returning the current pjax version
scrollTo	0	vertical position to scroll to after navigation. To avoid changing scroll position, pass false.
type	"GET"	see $.ajax
dataType	"html"	see $.ajax
container		CSS selector for the element where content should be replaced
url	link.href	a string or function that returns the URL for the ajax request
target	link	eventually the relatedTarget value for pjax events
fragment		CSS selector for the fragment to extract from ajax response

You can change the defaults globally by writing to the $.pjax.defaults object:

$.pjax.defaults.timeout = 1200

$.pjax.click

This is a lower level function used by $.fn.pjax itself. It allows you to get a little more control over the pjax event handling.

This example uses the current click context to set an ancestor element as the container:

if ($.support.pjax) {
  $(document).on('click', 'a[data-pjax]', function(event) {
    var container = $(this).closest('[data-pjax-container]')
    var containerSelector = '#' + container.id
    $.pjax.click(event, {container: containerSelector})
  })
}

NOTE Use the explicit $.support.pjax guard. We aren't using $.fn.pjax so we should avoid binding this event handler unless the browser is actually going to use pjax.

$.pjax.submit

Submits a form via pjax.

$(document).on('submit', 'form[data-pjax]', function(event) {
  $.pjax.submit(event, '#pjax-container')
})

$.pjax.reload

Initiates a request for the current URL to the server using pjax mechanism and replaces the container with the response. Does not add a browser history entry.

$.pjax.reload('#pjax-container', options)

$.pjax

Manual pjax invocation. Used mainly when you want to start a pjax request in a handler that didn't originate from a click. If you can get access to a click event, consider $.pjax.click(event) instead.

function applyFilters() {
  var url = urlForFilters()
  $.pjax({url: url, container: '#pjax-container'})
}

Events

All pjax events except pjax:click & pjax:clicked are fired from the pjax
container element.

<table>
<tr>
<th>event</th>
<th>cancel</th>
<th>arguments</th>
<th>notes</th>
</tr>
<tr>
<th colspan=4>event lifecycle upon following a pjaxed link</th>
</tr>
<tr>
<td><code>pjax:click</code></td>
<td>✔︎</td>
<td><code>options</code></td>
<td>fires from a link that got activated; cancel to prevent pjax</td>
</tr>
<tr>
<td><code>pjax:beforeSend</code></td>
<td>✔︎</td>
<td><code>xhr, options</code></td>
<td>can set XHR headers</td>
</tr>
<tr>
<td><code>pjax:start</code></td>
<td></td>
<td><code>xhr, options</code></td>
<td></td>
</tr>
<tr>
<td><code>pjax:send</code></td>
<td></td>
<td><code>xhr, options</code></td>
<td></td>
</tr>
<tr>
<td><code>pjax:clicked</code></td>
<td></td>
<td><code>options</code></td>
<td>fires after pjax has started from a link that got clicked</td>
</tr>
<tr>
<td><code>pjax:beforeReplace</code></td>
<td></td>
<td><code>contents, options</code></td>
<td>before replacing HTML with content loaded from the server</td>
</tr>
<tr>
<td><code>pjax:success</code></td>
<td></td>
<td><code>data, status, xhr, options</code></td>
<td>after replacing HTML content loaded from the server</td>
</tr>
<tr>
<td><code>pjax:timeout</code></td>
<td>✔︎</td>
<td><code>xhr, options</code></td>
<td>fires after <code>options.timeout</code>; will hard refresh unless canceled</td>
</tr>
<tr>
<td><code>pjax:error</code></td>
<td>✔︎</td>
<td><code>xhr, textStatus, error, options</code></td>
<td>on ajax error; will hard refresh unless canceled</td>
</tr>
<tr>
<td><code>pjax:complete</code></td>
<td></td>
<td><code>xhr, textStatus, options</code></td>
<td>always fires after ajax, regardless of result</td>
</tr>
<tr>
<td><code>pjax:end</code></td>
<td></td>
<td><code>xhr, options</code></td>
<td></td>
</tr>
<tr>
<th colspan=4>event lifecycle on browser Back/Forward navigation</th>
</tr>
<tr>
<td><code>pjax:popstate</code></td>
<td></td>
<td></td>
<td>event <code>direction</code> property: "back"/"forward"</td>
</tr>
<tr>
<td><code>pjax:start</code></td>
<td></td>
<td><code>null, options</code></td>
<td>before replacing content</td>
</tr>
<tr>
<td><code>pjax:beforeReplace</code></td>
<td></td>
<td><code>contents, options</code></td>
<td>right before replacing HTML with content from cache</td>
</tr>
<tr>
<td><code>pjax:end</code></td>
<td></td>
<td><code>null, options</code></td>
<td>after replacing content</td>
</tr>
</table>

pjax:send & pjax:complete are a good pair of events to use if you are implementing a
loading indicator. They'll only be triggered if an actual XHR request is made,
not if the content is loaded from cache:

$(document).on('pjax:send', function() {
  $('#loading').show()
})
$(document).on('pjax:complete', function() {
  $('#loading').hide()
})

An example of canceling a pjax:timeout event would be to disable the fallback
timeout behavior if a spinner is being shown:

$(document).on('pjax:timeout', function(event) {
  // Prevent default timeout redirection behavior
  event.preventDefault()
})

Advanced configuration

Reinitializing plugins/widget on new page content

The whole point of pjax is that it fetches and inserts new content without
refreshing the page. However, other jQuery plugins or libraries that are set to
react on page loaded event (such as DOMContentLoaded) will not pick up on
these changes. Therefore, it's usually a good idea to configure these plugins to
reinitialize in the scope of the updated page content. This can be done like so:

$(document).on('ready pjax:end', function(event) {
  $(event.target).initializeMyPlugin()
})

This will make $.fn.initializeMyPlugin() be called at the document level on
normal page load, and on the container level after any pjax navigation (either
after clicking on a link or going Back in the browser).

Response types that force a reload

By default, pjax will force a full reload of the page if it receives one of the
following responses from the server:

• Page content that includes <html> when fragment selector wasn't explicitly
  configured. Pjax presumes that the server's response hasn't been properly
  configured for pjax. If fragment pjax option is given, pjax will extract the
  content based on that selector.

• Page content that is blank. Pjax assumes that the server is unable to deliver
  proper pjax contents.

• HTTP response code that is 4xx or 5xx, indicating some server error.

Affecting the browser URL

If the server needs to affect the URL which will appear in the browser URL after
pjax navigation (like HTTP redirects work for normal requests), it can set the
X-PJAX-URL header:

def index
  request.headers['X-PJAX-URL'] = "http://example.com/hello"
end

Layout Reloading

Layouts can be forced to do a hard reload when assets or html changes.

First set the initial layout version in your header with a custom meta tag.

<meta http-equiv="x-pjax-version" content="v123">

Then from the server side, set the X-PJAX-Version header to the same.

if request.headers['X-PJAX']
  response.headers['X-PJAX-Version'] = "v123"
end

Deploying a deploy, bumping the version constant to force clients to do a full reload the next request getting the new layout and assets.