silverstripe-framework/src/Control/PjaxResponseNegotiator.php
2016-11-29 12:31:16 +13:00

144 lines
4.2 KiB
PHP

<?php
namespace SilverStripe\Control;
use SilverStripe\Core\Convert;
use InvalidArgumentException;
/**
* Handle the X-Pjax header that AJAX responses may provide, returning the
* fragment, or, in the case of non-AJAX form submissions, redirecting back
* to the submitter.
*
* X-Pjax ensures that users won't end up seeing the unstyled form HTML in
* their browser.
*
* If a JS error prevents the Ajax overriding of form submissions from happening.
*
* It also provides better non-JS operation.
*
* Caution: This API is volatile, and might eventually be replaced by a generic
* action helper system for controllers.
*/
class PjaxResponseNegotiator
{
/**
* See {@link respond()}
*
* @var array
*/
protected $callbacks = array();
protected $response = null;
/**
* Overriden fragments (if any). Otherwise uses fragments from the request.
*/
protected $fragmentOverride = null;
/**
* @param array $callbacks
* @param HTTPResponse $response An existing response to reuse (optional)
*/
public function __construct($callbacks = array(), $response = null)
{
$this->callbacks = $callbacks;
$this->response = $response;
}
public function getResponse()
{
if (!$this->response) {
$this->response = new HTTPResponse();
}
return $this->response;
}
public function setResponse($response)
{
$this->response = $response;
}
/**
* Out of the box, the handler "CurrentForm" value, which will return the rendered form.
* Non-Ajax calls will redirect back.
*
* @param HTTPRequest $request
* @param array $extraCallbacks List of anonymous functions or callables returning either a string
* or HTTPResponse, keyed by their fragment identifier. The 'default' key can
* be used as a fallback for non-ajax responses.
* @return HTTPResponse
* @throws HTTPResponse_Exception
*/
public function respond(HTTPRequest $request, $extraCallbacks = array())
{
// Prepare the default options and combine with the others
$callbacks = array_merge($this->callbacks, $extraCallbacks);
$response = $this->getResponse();
$responseParts = array();
if (isset($this->fragmentOverride)) {
$fragments = $this->fragmentOverride;
} elseif ($fragmentStr = $request->getHeader('X-Pjax')) {
$fragments = explode(',', $fragmentStr);
} else {
if ($request->isAjax()) {
throw new HTTPResponse_Exception("Ajax requests to this URL require an X-Pjax header.", 400);
} elseif (empty($callbacks['default'])) {
throw new HTTPResponse_Exception("Missing default response handler for this URL", 400);
}
$response->setBody(call_user_func($callbacks['default']));
return $response;
}
// Execute the fragment callbacks and build the response.
foreach ($fragments as $fragment) {
if (isset($callbacks[$fragment])) {
$res = call_user_func($callbacks[$fragment]);
$responseParts[$fragment] = $res ? (string) $res : $res;
} else {
throw new HTTPResponse_Exception("X-Pjax = '$fragment' not supported for this URL.", 400);
}
}
$response->setBody(Convert::raw2json($responseParts));
$response->addHeader('Content-Type', 'text/json');
return $response;
}
/**
* @param string $fragment
* @param Callable $callback
*/
public function setCallback($fragment, $callback)
{
$this->callbacks[$fragment] = $callback;
}
/**
* Set up fragment overriding - will completely replace the incoming fragments.
*
* @param array $fragments Fragments to insert.
* @return $this
*/
public function setFragmentOverride($fragments)
{
if (!is_array($fragments)) {
throw new InvalidArgumentException("fragments must be an array");
}
$this->fragmentOverride = $fragments;
return $this;
}
/**
* @return array
*/
public function getFragmentOverride()
{
return $this->fragmentOverride;
}
}