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.
	WFileResource (const std::string &fileName, WObject *parent=0)
	Creates a new resource for a file.
	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.
void	setFileName (const std::string &fileName)
	Sets a (different) filename.
const std::string &	fileName () const
	Returns the filename.
virtual void	handleRequest (const Http::Request &request, Http::Response &response)
	Handles a request.
Public Member Functions inherited from Wt::WStreamResource
	WStreamResource (WObject *parent=0)
	Default constructor.
	WStreamResource (const std::string &mimeType, WObject *parent=0)
	Creates a new resource with given mime-type.
	~WStreamResource ()
	Destructor.
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.
int	bufferSize () const
	Returns the buffer size.
Public Member Functions inherited from Wt::WResource
	WResource (WObject *parent=0)
	Creates a new resource.
	~WResource ()
	Destroys the resource.
void	suggestFileName (const Wt::WString &name, DispositionType dispositionType=Attachment)
	Suggests a filename to the user for the data streamed by this resource.
const Wt::WString &	suggestedFileName () const
	Returns the suggested file name.
void	setDispositionType (DispositionType cd)
	Configures the Content-Disposition header.
DispositionType	dispositionType () const
	Returns the currently configured content disposition.
void	setChanged ()
	Generates a new URL for this resource and emits the changed signal.
void	setInternalPath (const std::string &path)
	Sets an internal path for this resource.
std::string	internalPath () const
	Returns the internal path.
const std::string &	generateUrl ()
	Generates an URL for this resource.
const std::string &	url () const
	Returns the current URL for this resource.
Signal &	dataChanged ()
	Signal emitted when the data presented in this resource has changed.
void	setUploadProgress (bool enabled)
	Indicate interest in upload progress.
Signal< ::uint64_t,::uint64_t > &	dataReceived ()
	Signal emitted when data has been received for this resource.
void	write (std::ostream &out, const Http::ParameterMap &parameters=Http::ParameterMap(), const Http::UploadedFileMap &files=Http::UploadedFileMap())
	Stream the resource to a stream.
void	haveMoreData ()
	Indicate that more data is available.
Public Member Functions inherited from Wt::WObject
	WObject (WObject *parent=0)
	Create a WObject with a given parent object.
virtual	~WObject ()
	Destructor.
virtual const std::string	id () const
	Returns the (unique) identifier for this object.
void	setObjectName (const std::string &name)
	Sets an object name.
virtual std::string	objectName () const
	Returns the object name.
void	resetLearnedSlots ()
	Resets learned stateless slot implementations.
template<class T >
void	resetLearnedSlot (void(T::*method)())
	Resets a learned stateless slot implementation.
template<class T >
WStatelessSlot *	implementStateless (void(T::*method)())
	Declares a slot to be stateless and learn client-side behaviour on first invocation.
template<class T >
WStatelessSlot *	implementStateless (void(T::method)(), void(T::undoMethod)())
	Declares a slot to be stateless and learn client-side behaviour in advance.
template<class T >
WStatelessSlot *	implementJavaScript (void(T::*method)(), const std::string &jsCode)
	Provides a JavaScript implementation for a method.
void	addChild (WObject *child)
	Adds a child object.
virtual void	removeChild (WObject *child)
	Removes a child object.
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
enum	DispositionType { NoDisposition, Attachment, Inline }
	Values for the disposition type in the Content-Disposition header. More...
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.
Static Protected Member Functions inherited from Wt::WObject
static WObject *	sender ()
	Returns the sender of the current slot call.

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.

Reimplement this method so that a proper response is generated for the given request. From the request object you can access request parameters and whether the request is a continuation request. In the response object, you should set the mime type and stream the output data.

A request may also concern a continuation, indicated in Http::Request::continuation(), in which case the next part for a previously created continuation should be served.

While handling a request, which may happen at any time together with event handling, the library makes sure that the resource is not being concurrently deleted, but multiple requests may happend simultaneously for a single resource.

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