A resource which streams the data from a local file. More...

#include <Wt/WFileResource>

Inheritance diagram for Wt::WFileResource:

Public Member Functions
	WFileResource (WObject *parent=0)
	Default constructor. More...

	WFileResource (const std::string &fileName, WObject *parent=0)
	Creates a new resource for a file. More...

	WFileResource (const std::string &mimeType, const std::string &fileName, WObject *parent=0)
	Creates a new resource with given mime-type for a file.

	~WFileResource ()
	Destructor. More...

void	setFileName (const std::string &fileName)
	Sets a (different) filename. More...

const std::string &	fileName () const
	Returns the filename.

virtual void	handleRequest (const Http::Request &request, Http::Response &response)
	Handles a request. More...

Public Member Functions inherited from Wt::WStreamResource
	WStreamResource (WObject *parent=0)
	Default constructor. More...

	WStreamResource (const std::string &mimeType, WObject *parent=0)
	Creates a new resource with given mime-type.

	~WStreamResource ()
	Destructor. More...

void	setMimeType (const std::string &mimeType)
	Sets the mime-type.

const std::string &	mimeType () const
	Returns the mime-type.

void	setBufferSize (int size)
	Configures the buffer size. More...

int	bufferSize () const
	Returns the buffer size. More...

Public Member Functions inherited from Wt::WResource
	WResource (WObject *parent=0)
	Creates a new resource.

	~WResource ()
	Destroys the resource. More...

void	suggestFileName (const Wt::WString &name, DispositionType dispositionType=Attachment)
	Suggests a filename to the user for the data streamed by this resource. More...

const Wt::WString &	suggestedFileName () const
	Returns the suggested file name. More...

void	setDispositionType (DispositionType cd)
	Configures the Content-Disposition header. More...

DispositionType	dispositionType () const
	Returns the currently configured content disposition. More...

void	setChanged ()
	Generates a new URL for this resource and emits the changed signal. More...

void	setInternalPath (const std::string &path)
	Sets an internal path for this resource. More...

std::string	internalPath () const
	Returns the internal path. More...

const std::string &	generateUrl ()
	Generates an URL for this resource. More...

const std::string &	url () const
	Returns the current URL for this resource. More...

Signal &	dataChanged ()
	Signal emitted when the data presented in this resource has changed. More...

void	setUploadProgress (bool enabled)
	Indicate interest in upload progress. More...

Signal< ::uint64_t,::uint64_t > &	dataReceived ()
	Signal emitted when data has been received for this resource. More...

void	write (std::ostream &out, const Http::ParameterMap &parameters=Http::ParameterMap(), const Http::UploadedFileMap &files=Http::UploadedFileMap())
	Stream the resource to a stream. More...

virtual void	handleAbort (const Http::Request &request)
	Handles a continued request being aborted. More...

void	haveMoreData ()
	Indicate that more data is available. More...

Public Member Functions inherited from Wt::WObject
	WObject (WObject *parent=0)
	Create a WObject with a given parent object. More...

virtual	~WObject ()
	Destructor. More...

virtual const std::string	id () const
	Returns the (unique) identifier for this object. More...

virtual void	setObjectName (const std::string &name)
	Sets an object name. More...

virtual std::string	objectName () const
	Returns the object name. More...

void	resetLearnedSlots ()
	Resets learned stateless slot implementations. More...

template<class T >
void	resetLearnedSlot (void(T::*method)())
	Resets a learned stateless slot implementation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::*method)())
	Declares a slot to be stateless and learn client-side behaviour on first invocation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::method)(), void(T::undoMethod)())
	Declares a slot to be stateless and learn client-side behaviour in advance. More...

void	isNotStateless ()
	Marks the current function as not stateless. More...

template<class T >
WStatelessSlot *	implementJavaScript (void(T::*method)(), const std::string &jsCode)
	Provides a JavaScript implementation for a method. More...

void	addChild (WObject *child)
	Adds a child object. More...

virtual void	removeChild (WObject *child)
	Removes a child object. More...

const std::vector< WObject * > &	children () const
	Returns the children.

WObject *	parent () const
	Returns the parent object.

Additional Inherited Members
Public Types inherited from Wt::WResource
Public Types inherited from Wt::WObject
typedef void(WObject::*	Method) ()
	Typedef for a WObject method without arguments.

Protected Member Functions inherited from Wt::WStreamResource
void	handleRequestPiecewise (const Http::Request &request, Http::Response &response, std::istream &input)
	Handles a request and streams the data from a std::istream. More...

Protected Member Functions inherited from Wt::WResource
void	beingDeleted ()
	Prepares the resource for deletion. More...

Protected Member Functions inherited from Wt::WObject
virtual WStatelessSlot *	getStateless (Method method)
	On-demand stateless slot implementation. More...

Static Protected Member Functions inherited from Wt::WObject
static WObject *	sender ()
	Returns the sender of the current slot call. More...

Detailed Description

A resource which streams the data from a local file.

To update the resource, either use setFileName() to point it to a new file, or emit the WResource::dataChanged() signal when only the file contents has changed, but not the filename.

The resource makes use of continuations to transmit data piecewise, without blocking a thread or requiring the entire file to be read in memory. The size of the buffer can be changed using setBufferSize().

Usage examples:

Wt::WFileResource *csvFile = new Wt::WFileResource("text/csv", "/opt/files/afile.csv");
csvFile->suggestFileName("data.csv");
Wt::WAnchor *anchor = new Wt::WAnchor(csvFile, "CSV data");
Wt::WFileResource *imageFile = new Wt::WFileResource("image/png", "/opt/files/image.png");
imageFile->suggestFileName("data.png");
Wt::WImage *image = new Wt::WImage(imageFile, "PNG version");

See also: WStreamResource, WMemoryResource

Constructor & Destructor Documentation

Wt::WFileResource::WFileResource ( WObject * parent = 0 )

Default constructor.

You need to set a file name (and mime type) for the resource using setFileName() and setMimeType().

Wt::WFileResource::WFileResource	(	const std::string &	fileName,
		WObject *	parent = `0`
	)

Creates a new resource for a file.

The mime type defaults to "text/plain".

Wt::WFileResource::~WFileResource ( )

Destructor.

It is up to the user to make sure that the resource is no longer in use (by e.g. a WImage).

Member Function Documentation

void Wt::WFileResource::handleRequest	(	const Http::Request &	request,
		Http::Response &	response
	)

virtual

Handles a request.

You may want to specialize this function to compute the file on the fly. However, you need to take into account the fact that the WFileResource implementation may use continuations to split the download in smaller chunks. Your implementation should thus look like:

void handleRequest(const Http::Request& request,
                   Http::Response& response) {
  if (!request.continuation()) {
    ... prepare data
    setFileName(myTmpFile);
  }
  WFileResource::handleRequest(request, response);
}

Implements Wt::WResource.

void Wt::WFileResource::setFileName ( const std::string & fileName )

Sets a (different) filename.

Set the location of the file on the local filesystem which must be streamed for this resource.

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation