Wt::Http::ResponseContinuation Class Reference

A resource response continuation object. More...

#include <Wt/Http/ResponseContinuation>

Inherits enable_shared_from_this< ResponseContinuation >.

Public Member Functions
void	setData (const boost::any &data)
	Set data associated with the continuation. More...
boost::any	data ()
	Return data associated with the continuation. More...
WResource *	resource () const
	Return the resource.
void	waitForMoreData ()
	Wait for more data. More...
void	haveMoreData ()
	Indicates that we have more data. More...
bool	isWaitingForMoreData () const
	Returns whether this continuation is waiting for data. More...

Detailed Description

A resource response continuation object.

A response continuation object is used to keep track of a response which is to be continued.

You may associate data with the object using setData().

A continuation is used to resume sending more data later for this response. There are two possible reasons for this:

• the entire response is quite big and you may want to read and send it in smaller chunks. This avoids unbounded memory usage since the I/O layer buffers the response first in memory to send it then out to a possibly slow client using async I/O.
• you may not have any more data available, currently, but expect more data later. In that case you can call waitForMoreData() and later call WResource::haveMoreData() when more data is available.

See also

Response::createContinuation(), Request::continuation()

Member Function Documentation

boost::any Wt::Http::ResponseContinuation::data

(

)

Return data associated with the continuation.

See also

setData()

void Wt::Http::ResponseContinuation::haveMoreData

(

)

Indicates that we have more data.

This will allow the response to be resumed with a new call to WResource::handleRequest().

bool Wt::Http::ResponseContinuation::isWaitingForMoreData

(

)

const

Returns whether this continuation is waiting for data.

See also

waitForMoreData()

void Wt::Http::ResponseContinuation::setData

(

const boost::any &

data

)

Set data associated with the continuation.

You could do this to keep track of the state of sending the data for a WResource.

void Wt::Http::ResponseContinuation::waitForMoreData

(

)

Wait for more data.

This suspends the handling of this request until more data is available, indicated with a call to haveMoreData(), or to a resource globally using WResource::haveMoreData().