silverstripe-framework/core/control/RequestHandlingData.php

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<?php
/**
* This class is the base class of any Sapphire object that can be used to handle HTTP requests.
*
* Any RequestHandlingData object can be made responsible for handling its own segment of the URL namespace.
* The {@link Director} begins the URL parsing process; it will parse the beginning of the URL to identify which
* controller is being used. It will then call handleRequest on that Controller, passing it the parameters that it
* parsed from the URL, and the HTTPRequest that contains the remainder of the URL to be parsed.
*
* In Sapphire, URL parsing is distributed throughout the object graph. For example, suppose that we have a search form
* that contains a {@link TreeMultiSelectField}, Groups. We want to use ajax to load segments of this tree as they are needed
* rather than downloading the tree right at the beginning. We could use this URL to get the tree segment that appears underneath
* Group #36:
*
* admin/crm/SearchForm/fields/Groups/treesegment/36
*
* - Director will determine that admin/crm is controlled by a new ModelAdmin object, and pass control to that.
* - ModelAdmin will determine that SearchForm is controlled by a Form object returned by $this->SearchForm(), and pass control to that.
* - Form will determine that fields/Groups is controlled by the Groups field, a TreeMultiselectField, and pass control to that.
* - TreeMultiselectField will determine that treesegment/36 is handled by its treesegment() method. This method will return an HTML fragment that is output to the screen.
*
* {@link RequestHandlingData::handleRequest()} is where this behaviour is implemented.
*/
class RequestHandlingData extends ViewableData {
protected $request = null;
/**
* The default URL handling rules. This specifies that the next component of the URL corresponds to a method to
* be called on this RequestHandlingData object.
*
* The keys of this array are parse rules. See {@link HTTPRequest::match()} for a description of the rules available.
*
* The values of the array are the method to be called if the rule matches. If this value starts with a '$', then the
* named parameter of the parsed URL wil be used to determine the method name.
*/
static $url_handlers = array(
'$Action' => '$Action',
);
/**
* Define a list of action handling methods that are allowed to be called directly by URLs.
* The variable should be an array of action names. This sample shows the different values that it can contain:
*
* <code>
* array(
* 'someaction', // someaction can be accessed by anyone, any time
* 'otheraction' => true, // So can otheraction
* 'restrictedaction' => 'ADMIN', // restrictedaction can only be people with ADMIN privilege
* 'complexaction' '->canComplexAction' // complexaction can only be accessed if $this->canComplexAction() returns true
* );
* </code>
*/
static $allowed_actions = null;
/**
* Handles URL requests.
*
* - ViewableData::handleRequest() iterates through each rule in {@link self::$url_handlers}.
* - If the rule matches, the named method will be called.
* - If there is still more URL to be processed, then handleRequest() is called on the object that that method returns.
*
* Once all of the URL has been processed, the final result is returned. However, if the final result is an array, this
* array is interpreted as being additional template data to customise the 2nd to last result with, rather than an object
* in its own right. This is most frequently used when a Controller's action will return an array of data with which to
* customise the controller.
*
* @param $params The parameters taken from the parsed URL of the parent url handler
* @param $request The {@link HTTPRequest} object that is reponsible for distributing URL parsing
* @uses HTTPRequest
*/
function handleRequest($request) {
$this->request = $request;
foreach($this->stat('url_handlers') as $rule => $action) {
if(isset($_REQUEST['debug_request'])) Debug::message("Testing '$rule' with '" . $request->remaining() . "' on $this->class");
if($params = $request->match($rule, true)) {
if(isset($_REQUEST['debug_request'])) Debug::message("Rule '$rule' matched to action '$action' on $this->class");
// Actions can reference URL parameters, eg, '$Action/$ID/$OtherID' => '$Action',
if($action[0] == '$') $action = $params[substr($action,1)];
if($this->checkAccessAction($action)) {
$result = $this->$action($request);
} else {
return $this->httpError(403, "Action '$action' isn't allowed on class $this->class");
}
if($result instanceof HTTPResponse && $result->isError()) {
if(isset($_REQUEST['debug_request'])) Debug::message("Rule resulted in HTTP error; breaking");
return $result;
}
// If we return a RequestHandlingData, call handleRequest() on that, even if there is no more URL to parse.
// It might have its own handler. However, we only do this if we haven't just parsed an empty rule ourselves,
// to prevent infinite loops
if(!$request->isEmptyPattern($rule) && is_object($result) && $result instanceof RequestHandlingData) {
$returnValue = $result->handleRequest($request);
// Array results can be used to handle
if(is_array($returnValue)) $returnValue = $this->customise($returnValue);
return $returnValue;
// If we return some other data, and all the URL is parsed, then return that
} else if($request->allParsed()) {
return $result;
// But if we have more content on the URL and we don't know what to do with it, return an error.
} else {
return $this->httpError(400, "I can't handle sub-URLs of a $this->class object.");
}
break;
}
}
// If nothing matches, return this object
return $this;
}
/**
* Check that the given action is allowed to be called from a URL.
* It will interrogate {@link self::$allowed_actions} to determine this.
*/
function checkAccessAction($action) {
// Collate self::$allowed_actions from this class and all parent classes
$access = null;
$className = $this->class;
while($className != 'RequestHandlingData') {
// Merge any non-null parts onto $access.
$accessPart = eval("return $className::\$allowed_actions;");
if($accessPart !== null) $access = array_merge((array)$access, $accessPart);
// Build an array of parts for checking if part[0] == part[1], which means that this class doesn't directly define it.
$accessParts[] = $accessPart;
$className = get_parent_class($className);
}
// Add $allowed_actions from extensions
if($this->extension_instances) {
foreach($this->extension_instances as $inst) {
$accessPart = $inst->stat('allowed_actions');
if($accessPart !== null) $access = array_merge((array)$access, $accessPart);
}
}
if($access === null || (isset($accessParts[1]) && $accessParts[0] === $accessParts[1])) {
// user_error("Deprecated: please define static \$allowed_actions on your Controllers for security purposes", E_USER_NOTICE);
return true;
}
if($action == 'index') return true;
if(isset($access[$action])) {
$test = $access[$action];
if($test === true) return true;
if(substr($test,0,2) == '->') {
$funcName = substr($test,2);
return $this->$funcName();
}
if(Permission::check($test)) return true;
} else if((($key = array_search($action, $access)) !== false) && is_numeric($key)) {
return true;
}
return false;
}
/**
* Throw an HTTP error instead of performing the normal processing
* @todo This doesn't work properly right now. :-(
*/
function httpError($errorCode, $errorMessage = null) {
$r = new HTTPResponse();
$r->setBody($errorMessage);
$r->setStatuscode($errorCode);
return $r;
}
}