silverstripe-framework/core/control/RequestHandler.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 RequestHandler 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 {@link handleRequest()} on that Controller, passing it the parameters that it
* parsed from the URL, and the {@link SS_HTTPRequest} that contains the remainder of the URL to be parsed.
*
* You can use ?debug_request=1 to view information about the different components and rule matches for a specific URL.
*
* In Sapphire, URL parsing is distributed throughout the object graph. For example, suppose that we have a search form
* that contains a {@link TreeMultiSelectField} named "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/field/Groups/treesegment/36"
* - Director will determine that admin/crm is controlled by a new ModelAdmin object, and pass control to that.
* Matching Director Rule: "admin/crm" => "ModelAdmin" (defined in mysite/_config.php)
* - ModelAdmin will determine that SearchForm is controlled by a Form object returned by $this->SearchForm(), and pass control to that.
* Matching $url_handlers: "$Action" => "$Action" (defined in RequestHandler class)
* - Form will determine that field/Groups is controlled by the Groups field, a TreeMultiselectField, and pass control to that.
* Matching $url_handlers: 'field/$FieldName!' => 'handleField' (defined in Form class)
* - 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.
* Matching $url_handlers: "$Action/$ID" => "handleItem" (defined in TreeMultiSelectField class)
*
* {@link RequestHandler::handleRequest()} is where this behaviour is implemented.
*
* @package sapphire
* @subpackage control
*/
class RequestHandler extends ViewableData {
protected $request = null;
/**
* This variable records whether RequestHandler::__construct()
* was called or not. Useful for checking if subclasses have
* called parent::__construct()
*
* @var boolean
*/
protected $brokenOnConstruct = true;
/**
* The default URL handling rules. This specifies that the next component of the URL corresponds to a method to
* be called on this RequestHandlingData object.
*
* The keys of this array are parse rules. See {@link SS_HTTPRequest::match()} for a description of the rules available.
*
* The values of the array are the method to be called if the rule matches. If this value starts with a '$', 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;
public function __construct() {
$this->brokenOnConstruct = false;
parent::__construct();
}
/**
* Handles URL requests.
*
* - ViewableData::handleRequest() iterates through each rule in {@link self::$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 $request The {@link SS_HTTPRequest} object that is reponsible for distributing URL parsing
* @uses SS_HTTPRequest
* @uses SS_HTTPRequest->match()
* @return SS_HTTPResponse|RequestHandler|string|array
*/
function handleRequest(SS_HTTPRequest $request) {
// $handlerClass is used to step up the class hierarchy to implement url_handlers inheritance
$handlerClass = ($this->class) ? $this->class : get_class($this);
if($this->brokenOnConstruct) {
user_error("parent::__construct() needs to be called on {$handlerClass}::__construct()", E_USER_WARNING);
}
$this->request = $request;
// We stop after RequestHandler; in other words, at ViewableData
while($handlerClass && $handlerClass != 'ViewableData') {
$urlHandlers = Object::get_static($handlerClass, 'url_handlers');
if($urlHandlers) foreach($urlHandlers as $rule => $action) {
if(isset($_REQUEST['debug_request'])) Debug::message("Testing '$rule' with '" . $request->remaining() . "' on $this->class");
if($params = $request->match($rule, true)) {
// FIXME: This unnecessary coupling was added to fix a bug in Image_Uploader.
if($this instanceof Controller) $this->urlParams = $request->allParams();
if(isset($_REQUEST['debug_request'])) {
Debug::message("Rule '$rule' matched to action '$action' on $this->class. Latest request params: " . var_export($request->latestParams(), true));
}
// Actions can reference URL parameters, eg, '$Action/$ID/$OtherID' => '$Action',
if($action[0] == '$') $action = $params[substr($action,1)];
if($this->checkAccessAction($action)) {
if(!$action) {
if(isset($_REQUEST['debug_request'])) Debug::message("Action not set; using default action method name 'index'");
$action = "index";
} else if(!is_string($action)) {
user_error("Non-string method name: " . var_export($action, true), E_USER_ERROR);
}
try {
$result = $this->$action($request);
} catch(SS_HTTPResponse_Exception $responseException) {
$result = $responseException->getResponse();
}
} else {
return $this->httpError(403, "Action '$action' isn't allowed on class $this->class");
}
if($result instanceof SS_HTTPResponse && $result->isError()) {
if(isset($_REQUEST['debug_request'])) Debug::message("Rule resulted in HTTP error; breaking");
return $result;
}
// If we return a RequestHandler, call handleRequest() on that, even if there is no more URL to parse.
// It might have its own handler. However, we only do this if we haven't just parsed an empty rule ourselves,
// to prevent infinite loops
if(!$request->isEmptyPattern($rule) && is_object($result) && $result instanceof RequestHandler) {
$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(404, "I can't handle sub-URLs of a $this->class object.");
}
return $this;
}
}
$handlerClass = get_parent_class($handlerClass);
}
// If nothing matches, return this object
return $this;
}
/**
* Get a unified array of allowed actions on this controller (if such data is available) from both the controller
* ancestry and any extensions.
*
* @return array|null
*/
public function allowedActions() {
$actions = Object::combined_static(get_class($this), 'allowed_actions', 'RequestHandler');
foreach($this->extension_instances as $extension) {
if($extensionActions = Object::get_static(get_class($extension), 'allowed_actions')) {
$actions = array_merge($actions, $extensionActions);
}
}
if($actions) {
// convert all keys and values to lowercase to
// allow for easier comparison, unless it is a permission code
$actions = array_change_key_case($actions, CASE_LOWER);
foreach($actions as $key => $value) {
if(is_numeric($key)) $actions[$key] = strtolower($value);
}
return $actions;
}
}
/**
* Checks if this request handler has a specific action (even if the current user cannot access it).
*
* @param string $action
* @return bool
*/
public function hasAction($action) {
if($action == 'index') return true;
$action = strtolower($action);
$actions = $this->allowedActions();
if(is_array($actions)) {
if(array_key_exists($action, $actions) || in_array($action, $actions)) {
return true;
}
}
if(!is_array($actions) || !$this->uninherited('allowed_actions')) {
if($action != 'init' && $action != 'run' && method_exists($this, $action)) return true;
}
return false;
}
/**
* Check that the given action is allowed to be called from a URL.
* It will interrogate {@link self::$allowed_actions} to determine this.
*/
function checkAccessAction($action) {
$action = strtolower($action);
$allowedActions = $this->allowedActions();
if($allowedActions) {
// check for specific action rules first, and fall back to global rules defined by asterisk
foreach(array($action,'*') as $actionOrAll) {
// check if specific action is set
if(isset($allowedActions[$actionOrAll])) {
$test = $allowedActions[$actionOrAll];
if($test === true || $test === 1 || $test === '1') {
// Case 1: TRUE should always allow access
return true;
} elseif(substr($test, 0, 2) == '->') {
// Case 2: Determined by custom method with "->" prefix
return $this->{substr($test, 2)}();
} else {
// Case 3: Value is a permission code to check the current member against
return Permission::check($test);
}
} elseif((($key = array_search($actionOrAll, $allowedActions)) !== false) && is_numeric($key)) {
// Case 4: Allow numeric array notation (search for array value as action instead of key)
return true;
}
}
}
// If we get here an the action is 'index', then it hasn't been specified, which means that
// it should be allowed.
if($action == 'index') return true;
if($allowedActions === null || !$this->uninherited('allowed_actions')) {
// If no allowed_actions are provided, then we should only let through actions that aren't handled by magic methods
// we test this by calling the unmagic method_exists and comparing it to the magic $this->hasMethod(). This will
// still let through actions that are handled by templates.
return method_exists($this, $action) || !$this->hasMethod($action);
}
return false;
}
/**
* Throws a HTTP error response encased in a {@link SS_HTTPResponse_Exception}, which is later caught in
* {@link RequestHandler::handleAction()} and returned to the user.
*
* @param int $errorCode
* @param string $errorMessage
* @uses SS_HTTPResponse_Exception
*/
public function httpError($errorCode, $errorMessage = null) {
throw new SS_HTTPResponse_Exception($errorMessage, $errorCode);
}
/**
* Returns the SS_HTTPRequest object that this controller is using.
*
* @return SS_HTTPRequest
*/
function getRequest() {
return $this->request;
}
}