silverstripe-framework/api/RestfulServer.php
Andrew O'Neil 60f75c5ca4 Merged changes from 2.3 branch
git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@71172 467b73ca-7a2a-4603-9d3b-597d59a354a9
2009-02-01 23:49:53 +00:00

602 lines
21 KiB
PHP

<?php
/**
* @package sapphire
* @subpackage api
*
* Sapphire's generic RESTful server.
*
* This class gives your application a RESTful API for free. All you have to do is define static $api_access = true on
* the appropriate DataObjects. You will need to ensure that all of your data manipulation and security is defined in
* your model layer (ie, the DataObject classes) and not in your Controllers. This is the recommended design for Sapphire
* applications.
*
* Example DataObject with simple api access, giving full access to all object properties and relations,
* unless explicitly controlled through model permissions.
* <code>
* class Article extends DataObject {
* static $db = array('Title'=>'Text','Published'=>'Boolean');
* static $api_access = true;
* }
* </code>
*
* * Example DataObject with advanced api access, limiting viewing and editing to Title attribute only:
* <code>
* class Article extends DataObject {
* static $db = array('Title'=>'Text','Published'=>'Boolean');
* static $api_access = array(
* 'view' => array('Title'),
* 'edit' => array('Title'),
* );
* }
* </code>
*
* Supported operations:
* - GET /api/v1/(ClassName)/(ID) - gets a database record
* - GET /api/v1/(ClassName)/(ID)/(Relation) - get all of the records linked to this database record by the given reatlion
* - GET /api/v1/(ClassName)?(Field)=(Val)&(Field)=(Val) - searches for matching database records
* - POST /api/v1/(ClassName) - create a new database record
* - PUT /api/v1/(ClassName)/(ID) - updates a database record
* - PUT /api/v1/(ClassName)/(ID)/(Relation) - updates a relation, replacing the existing record(s) (NOT IMPLEMENTED YET)
* - POST /api/v1/(ClassName)/(ID)/(Relation) - updates a relation, appending to the existing record(s) (NOT IMPLEMENTED YET)
*
* - DELETE /api/v1/(ClassName)/(ID) - deletes a database record (NOT IMPLEMENTED YET)
* - DELETE /api/v1/(ClassName)/(ID)/(Relation)/(ForeignID) - remove the relationship between two database records, but don't actually delete the foreign object (NOT IMPLEMENTED YET)
*
* - POST /api/v1/(ClassName)/(ID)/(MethodName) - executes a method on the given object (e.g, publish)
*
* You can trigger searches based on the fields specified on {@link DataObject::searchable_fields} and passed
* through {@link DataObject::getDefaultSearchContext()}. Just add a key-value pair with the search-term
* to the url, e.g. /api/v1/(ClassName)/?Title=mytitle.
*
* Other url-modifiers:
* - &limit=<numeric>: Limit the result set
* - &relationdepth=<numeric>: Displays links to existing has-one and has-many relationships to a certain depth (Default: 1)
* - &fields=<string>: Comma-separated list of fields on the output object (defaults to all database-columns).
* Handy to limit output for bandwidth and performance reasons.
* - &sort=<myfield>&dir=<asc|desc>
* - &add_fields=<string>: Comma-separated list of additional fields, for example dynamic getters.
*
* Access control is implemented through the usual Member system with Basicauth authentication only.
* By default, you have to bear the ADMIN permission to retrieve or send any data.
*
* You should override the following built-in methods to customize permission control on a
* class- and object-level:
* - {@link DataObject::canView()}
* - {@link DataObject::canEdit()}
* - {@link DataObject::canDelete()}
* - {@link DataObject::canCreate()}
* See {@link DataObject} documentation for further details.
*
* You can specify the character-encoding for any input on the HTTP Content-Type.
* At the moment, only UTF-8 is supported. All output is made in UTF-8 regardless of Accept headers.
*
* @todo Finish RestfulServer_Item and RestfulServer_List implementation and re-enable $url_handlers
* @todo Implement PUT/POST/DELETE for relations
* @todo Access-Control for relations (you might be allowed to view Members and Groups, but not their relation with each other)
* @todo Make SearchContext specification customizeable for each class
* @todo Allow for range-searches (e.g. on Created column)
* @todo Allow other authentication methods (currently only HTTP BasicAuth)
* @todo Filter relation listings by $api_access and canView() permissions
* @todo Exclude relations when "fields" are specified through URL (they should be explicitly requested in this case)
* @todo Custom filters per DataObject subclass, e.g. to disallow showing unpublished pages in SiteTree/Versioned/Hierarchy
* @todo URL parameter namespacing for search-fields, limit, fields, add_fields (might all be valid dataobject properties)
* e.g. you wouldn't be able to search for a "limit" property on your subclass as its overlayed with the search logic
* @todo i18n integration (e.g. Page/1.xml?lang=de_DE)
* @todo Access to decoratable methods/relations like SiteTree/1/Versions or SiteTree/1/Version/22
* @todo Respect $api_access array notation in search contexts
*/
class RestfulServer extends Controller {
static $url_handlers = array(
'$ClassName/$ID/$Relation' => 'handleAction'
#'$ClassName/#ID' => 'handleItem',
#'$ClassName' => 'handleList',
);
protected static $api_base = "api/v1/";
/**
* If no extension is given in the request, resolve to this extension
* (and subsequently the {@link self::$default_mimetype}.
*
* @var string
*/
public static $default_extension = "xml";
/**
* If no extension is given, resolve the request to this mimetype.
*
* @var string
*/
protected static $default_mimetype = "text/xml";
/**
* @uses authenticate()
* @var Member
*/
protected $member;
/*
function handleItem($request) {
return new RestfulServer_Item(DataObject::get_by_id($request->param("ClassName"), $request->param("ID")));
}
function handleList($request) {
return new RestfulServer_List(DataObject::get($request->param("ClassName"),""));
}
*/
/**
* This handler acts as the switchboard for the controller.
* Since no $Action url-param is set, all requests are sent here.
*/
function index() {
ContentNegotiator::disable();
if(!isset($this->urlParams['ClassName'])) return $this->notFound();
$className = $this->urlParams['ClassName'];
$id = (isset($this->urlParams['ID'])) ? $this->urlParams['ID'] : null;
$relation = (isset($this->urlParams['Relation'])) ? $this->urlParams['Relation'] : null;
// Check input formats
if(!class_exists($className)) return $this->notFound();
if($id && !is_numeric($id)) return $this->notFound();
if($relation && !preg_match('/^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*$/', $relation)) return $this->notFound();
// if api access is disabled, don't proceed
$apiAccess = singleton($className)->stat('api_access');
if(!$apiAccess) return $this->permissionFailure();
// authenticate through HTTP BasicAuth
$this->member = $this->authenticate();
// handle different HTTP verbs
if($this->request->isGET() || $this->request->isHEAD()) return $this->getHandler($className, $id, $relation);
if($this->request->isPOST()) return $this->postHandler($className, $id, $relation);
if($this->request->isPUT()) return $this->putHandler($className, $id, $relation);
if($this->request->isDELETE()) return $this->deleteHandler($className, $id, $relation);
// if no HTTP verb matches, return error
return $this->methodNotAllowed();
}
/**
* Handler for object read.
*
* The data object will be returned in the following format:
*
* <ClassName>
* <FieldName>Value</FieldName>
* ...
* <HasOneRelName id="ForeignID" href="LinkToForeignRecordInAPI" />
* ...
* <HasManyRelName>
* <ForeignClass id="ForeignID" href="LinkToForeignRecordInAPI" />
* <ForeignClass id="ForeignID" href="LinkToForeignRecordInAPI" />
* </HasManyRelName>
* ...
* <ManyManyRelName>
* <ForeignClass id="ForeignID" href="LinkToForeignRecordInAPI" />
* <ForeignClass id="ForeignID" href="LinkToForeignRecordInAPI" />
* </ManyManyRelName>
* </ClassName>
*
* Access is controlled by two variables:
*
* - static $api_access must be set. This enables the API on a class by class basis
* - $obj->canView() must return true. This lets you implement record-level security
*
* @todo Access checking
*
* @param String $className
* @param Int $id
* @param String $relation
* @return String The serialized representation of the requested object(s) - usually XML or JSON.
*/
protected function getHandler($className, $id, $relationName) {
$sort = array(
'sort' => $this->request->getVar('sort'),
'dir' => $this->request->getVar('dir')
);
$limit = array(
'start' => $this->request->getVar('start'),
'limit' => $this->request->getVar('limit')
);
$params = $this->request->getVars();
$responseFormatter = $this->getResponseDataFormatter();
if(!$responseFormatter) return $this->unsupportedMediaType();
// $obj can be either a DataObject or a DataObjectSet,
// depending on the request
if($id) {
// Format: /api/v1/<MyClass>/<ID>
$query = $this->getObjectQuery($className, $id, $params);
$obj = singleton($className)->buildDataObjectSet($query->execute());
if(!$obj) return $this->notFound();
$obj = $obj->First();
if(!$obj->canView()) return $this->permissionFailure();
// Format: /api/v1/<MyClass>/<ID>/<Relation>
if($relationName) {
$query = $this->getObjectRelationQuery($obj, $params, $sort, $limit, $relationName);
if($query === false) return $this->notFound();
$obj = singleton($className)->buildDataObjectSet($query->execute());
}
} else {
// Format: /api/v1/<MyClass>
$query = $this->getObjectsQuery($className, $params, $sort, $limit);
$obj = singleton($className)->buildDataObjectSet($query->execute());
// show empty serialized result when no records are present
if(!$obj) $obj = new DataObjectSet();
}
$this->getResponse()->addHeader('Content-Type', $responseFormatter->getOutputContentType());
$rawFields = $this->request->getVar('fields');
$fields = $rawFields ? explode(',', $rawFields) : null;
if($obj instanceof DataObjectSet) {
$responseFormatter->setTotalSize($query->unlimitedRowCount());
return $responseFormatter->convertDataObjectSet($obj, $fields);
} else if(!$obj) {
$responseFormatter->setTotalSize(0);
return $responseFormatter->convertDataObjectSet(new DataObjectSet(), $fields);
} else {
return $responseFormatter->convertDataObject($obj, $fields);
}
}
/**
* Uses the default {@link SearchContext} specified through
* {@link DataObject::getDefaultSearchContext()} to augument
* an existing query object (mostly a component query from {@link DataObject})
* with search clauses.
*
* @todo Allow specifying of different searchcontext getters on model-by-model basis
*
* @param string $className
* @param array $params
* @return DataObjectSet
*/
protected function getSearchQuery($className, $params = null, $sort = null, $limit = null, $existingQuery = null) {
if(singleton($className)->hasMethod('getRestfulSearchContext')) {
$searchContext = singleton($className)->{'getRestfulSearchContext'}();
} else {
$searchContext = singleton($className)->getDefaultSearchContext();
}
$query = $searchContext->getQuery($params, $sort, $limit, $existingQuery);
return $query;
}
/**
* Returns a dataformatter instance based on the request
* extension or mimetype. Falls back to {@link self::$default_extension}.
*
* @param boolean $includeAcceptHeader Determines wether to inspect and prioritize any HTTP Accept headers
* @return DataFormatter
*/
protected function getDataFormatter($includeAcceptHeader = false) {
$extension = $this->request->getExtension();
$contentTypeWithEncoding = $this->request->getHeader('Content-Type');
preg_match('/([^;]*)/',$contentTypeWithEncoding, $contentTypeMatches);
$contentType = $contentTypeMatches[0];
$accept = $this->request->getHeader('Accept');
$mimetypes = $this->request->getAcceptMimetypes();
// get formatter
if(!empty($extension)) {
$formatter = DataFormatter::for_extension($extension);
}elseif($includeAcceptHeader && !empty($accept) && $accept != '*/*') {
$formatter = DataFormatter::for_mimetypes($mimetypes);
} elseif(!empty($contentType)) {
$formatter = DataFormatter::for_mimetype($contentType);
} else {
$formatter = DataFormatter::for_extension(self::$default_extension);
}
if(!$formatter) return false;
// set custom fields
if($customAddFields = $this->request->getVar('add_fields')) $formatter->setCustomAddFields(explode(',',$customAddFields));
if($customFields = $this->request->getVar('fields')) $formatter->setCustomFields(explode(',',$customFields));
$formatter->setCustomRelations($this->getAllowedRelations($this->urlParams['ClassName']));
$apiAccess = singleton($this->urlParams['ClassName'])->stat('api_access');
if(is_array($apiAccess)) {
$formatter->setCustomAddFields(array_intersect((array)$formatter->getCustomAddFields(), (array)$apiAccess['view']));
if($formatter->getCustomFields()) {
$formatter->setCustomFields(array_intersect((array)$formatter->getCustomFields(), (array)$apiAccess['view']));
} else {
$formatter->setCustomFields((array)$apiAccess['view']);
}
if($formatter->getCustomRelations()) {
$formatter->setCustomRelations(array_intersect((array)$formatter->getCustomRelations(), (array)$apiAccess['view']));
} else {
$formatter->setCustomRelations((array)$apiAccess['view']);
}
}
// set relation depth
$relationDepth = $this->request->getVar('relationdepth');
if(is_numeric($relationDepth)) $formatter->relationDepth = (int)$relationDepth;
return $formatter;
}
protected function getRequestDataFormatter() {
return $this->getDataFormatter(false);
}
protected function getResponseDataFormatter() {
return $this->getDataFormatter(true);
}
/**
* Handler for object delete
*/
protected function deleteHandler($className, $id) {
$obj = DataObject::get_by_id($className, $id);
if(!$obj) return $this->notFound();
if(!$obj->canDelete()) return $this->permissionFailure();
$obj->delete();
$this->getResponse()->setStatusCode(204); // No Content
return true;
}
/**
* Handler for object write
*/
protected function putHandler($className, $id) {
$obj = DataObject::get_by_id($className, $id);
if(!$obj) return $this->notFound();
if(!$obj->canEdit()) return $this->permissionFailure();
$reqFormatter = $this->getRequestDataFormatter();
if(!$reqFormatter) return $this->unsupportedMediaType();
$responseFormatter = $this->getResponseDataFormatter();
if(!$responseFormatter) return $this->unsupportedMediaType();
$obj = $this->updateDataObject($obj, $reqFormatter);
$this->getResponse()->setStatusCode(200); // Success
$this->getResponse()->addHeader('Content-Type', $responseFormatter->getOutputContentType());
$objHref = Director::absoluteURL(self::$api_base . "$obj->class/$obj->ID");
$this->getResponse()->addHeader('Location', $objHref);
return $responseFormatter->convertDataObject($obj);
}
/**
* Handler for object append / method call.
*
* @todo Posting to an existing URL (without a relation)
* current resolves in creatig a new element,
* rather than a "Conflict" message.
*/
protected function postHandler($className, $id) {
if($id) {
$this->response->setStatusCode(409);
return 'Conflict';
}
if(!singleton($className)->canCreate()) return $this->permissionFailure();
$obj = new $className();
$reqFormatter = $this->getRequestDataFormatter();
if(!$reqFormatter) return $this->unsupportedMediaType();
$responseFormatter = $this->getResponseDataFormatter();
$obj = $this->updateDataObject($obj, $reqFormatter);
$this->getResponse()->setStatusCode(201); // Created
$this->getResponse()->addHeader('Content-Type', $responseFormatter->getOutputContentType());
$objHref = Director::absoluteURL(self::$api_base . "$obj->class/$obj->ID");
$this->getResponse()->addHeader('Location', $objHref);
return $responseFormatter->convertDataObject($obj);
}
/**
* Converts either the given HTTP Body into an array
* (based on the DataFormatter instance), or returns
* the POST variables.
* Automatically filters out certain critical fields
* that shouldn't be set by the client (e.g. ID).
*
* @param DataObject $obj
* @param DataFormatter $formatter
* @return DataObject The passed object
*/
protected function updateDataObject($obj, $formatter) {
// if neither an http body nor POST data is present, return error
$body = $this->request->getBody();
if(!$body && !$this->request->postVars()) {
$this->getResponse()->setStatusCode(204); // No Content
return 'No Content';
}
if(!empty($body)) {
$data = $formatter->convertStringToArray($body);
} else {
// assume application/x-www-form-urlencoded which is automatically parsed by PHP
$data = $this->request->postVars();
}
// @todo Disallow editing of certain keys in database
$data = array_diff_key($data, array('ID','Created'));
$apiAccess = singleton($this->urlParams['ClassName'])->stat('api_access');
if(is_array($apiAccess) && isset($apiAccess['edit'])) {
$data = array_intersect_key($data, array_combine($apiAccess['edit'],$apiAccess['edit']));
}
$obj->update($data);
$obj->write();
return $obj;
}
/**
* Gets a single DataObject by ID,
* through a request like /api/v1/<MyClass>/<MyID>
*
* @param string $className
* @param int $id
* @param array $params
* @return SQLQuery
*/
protected function getObjectQuery($className, $id, $params) {
$baseClass = ClassInfo::baseDataClass($className);
return singleton($className)->buildSQL(
"\"$baseClass\".ID = {$id}"
);
}
/**
* @param DataObject $obj
* @param array $params
* @param int|array $sort
* @param int|array $limit
* @return SQLQuery
*/
protected function getObjectsQuery($className, $params, $sort, $limit) {
return $this->getSearchQuery($className, $params, $sort, $limit);
}
/**
* @param DataObject $obj
* @param array $params
* @param int|array $sort
* @param int|array $limit
* @param string $relationName
* @return SQLQuery|boolean
*/
protected function getObjectRelationQuery($obj, $params, $sort, $limit, $relationName) {
if($obj->hasMethod("{$relationName}Query")) {
// @todo HACK Switch to ComponentSet->getQuery() once we implement it (and lazy loading)
$query = $obj->{"{$relationName}Query"}(null, $sort, null, $limit);
$relationClass = $obj->{"{$relationName}Class"}();
} elseif($relationClass = $obj->many_many($relationName)) {
$query = $obj->getManyManyComponentsQuery($relationName);
} elseif($relationClass = $obj->has_many($relationName)) {
$query = $obj->getComponentsQuery($relationName);
} elseif($relationClass = $obj->has_one($relationName)) {
$query = null;
} else {
return false;
}
// get all results
return $this->getSearchQuery($relationClass, $params, $sort, $limit, $query);
}
protected function permissionFailure() {
// return a 401
$this->getResponse()->setStatusCode(403);
return "You don't have access to this item through the API.";
}
protected function notFound() {
// return a 404
$this->getResponse()->setStatusCode(404);
return "That object wasn't found";
}
protected function methodNotAllowed() {
$this->getResponse()->setStatusCode(405);
return "Method Not Allowed";
}
protected function unsupportedMediaType() {
$this->response->setStatusCode(415); // Unsupported Media Type
return "Unsupported Media Type";
}
protected function authenticate() {
if(!isset($_SERVER['PHP_AUTH_USER']) || !isset($_SERVER['PHP_AUTH_PW'])) return false;
if($member = Member::currentMember()) return $member;
$member = MemberAuthenticator::authenticate(array(
'Email' => $_SERVER['PHP_AUTH_USER'],
'Password' => $_SERVER['PHP_AUTH_PW'],
), null);
if($member) {
$member->LogIn(false);
return $member;
} else {
return false;
}
}
/**
* Return only relations which have $api_access enabled.
* @todo Respect field level permissions once they are available in core
*
* @param string $class
* @param Member $member
* @return array
*/
protected function getAllowedRelations($class, $member = null) {
$allowedRelations = array();
$obj = singleton($class);
$relations = (array)$obj->has_one() + (array)$obj->has_many() + (array)$obj->many_many();
if($relations) foreach($relations as $relName => $relClass) {
if(singleton($relClass)->stat('api_access')) {
$allowedRelations[] = $relName;
}
}
return $allowedRelations;
}
}
/**
* Restful server handler for a DataObjectSet
*/
class RestfulServer_List {
static $url_handlers = array(
'#ID' => 'handleItem',
);
function __construct($list) {
$this->list = $list;
}
function handleItem($request) {
return new RestulServer_Item($this->list->getById($request->param('ID')));
}
}
/**
* Restful server handler for a single DataObject
*/
class RestfulServer_Item {
static $url_handlers = array(
'$Relation' => 'handleRelation',
);
function __construct($item) {
$this->item = $item;
}
function handleRelation($request) {
$funcName = $request('Relation');
$relation = $this->item->$funcName();
if($relation instanceof DataObjectSet) return new RestfulServer_List($relation);
else return new RestfulServer_Item($relation);
}
}