transfer::data::destination(n) ______________________________________________________________________________
NAME
transfer::data::destination - Data destination
SYNOPSIS
package require Tcl 8.4
package require snit ?1.0?
package require transfer::data::destination ?0.2?
transfer::data::destination objectName ?options...?
objectName method ?arg arg ...?
objectName destroy
objectName put chunk
objectName done
objectName valid msgvar
objectName receive channel done
_________________________________________________________________
DESCRIPTION
This package provides objects mainly describing the destination of a
data transfer. They are also able to initiate the reception of informa-
tion from a channel into the described destination.
API
transfer::data::destination objectName ?options...?
This command creates a new data destination object with an asso-
ciated Tcl command whose name is objectName. This object com-
mand is explained in full detail in the sections Object command
and Object methods. The set of supported options is explained in
section Options.
The object command will be created under the current namespace
if the objectName is not fully qualified, and in the specified
namespace otherwise. The fully qualified name of the object
command is returned as the result of the command.
OBJECT COMMAND
All objects created by the ::transfer::data::destination command have
the following general form:
objectName method ?arg arg ...?
The method method and its arg'uments determine the exact behav-
ior of the command. See section Object methods for the detailed
specifications.
OBJECT METHODS
objectName destroy
This method destroys the object. Doing so while the object is
busy with the reception of information from a channel will cause
errors later on, when the reception completes and tries to
access the now missing data structures of the destroyed object.
objectName put chunk
The main receptor method. Saves the received chunk of data into
the configured destination. It has to be called for each piece
of data received.
objectName done
The secondary receptor method. Finalizes the receiver. It has to
be called when the receiving channel signals EOF. Afterward nei-
ther itself nor method put can be called anymore.
objectName valid msgvar
This method checks the configuration of the object for validity.
It returns a boolean flag as result, whose value is True if the
object is valid, and False otherwise. In the latter case the
variable whose name is stored in msgvar is set to an error mes-
sage describing the problem found with the configuration. Other-
wise this variable is not touched.
objectName receive channel done
This method initiates the reception of data from the specified
channel. The received data will be stored into the configured
destination, via calls to the methods put and done. When the
reception completes the command prefix done is invoked, with the
number of received characters appended to it as the sole addi-
tional argument.
OPTIONS
All data destinations support the options listed below. It should be
noted that all are semi-exclusive, each specifying a different type of
destination and associated information. If these options are specified
more than once then the last option specified is used to actually con-
figure the object.
-channel handle
This option specifies that the destination of the data is a
channel, and its associated argument is the handle of the chan-
nel to write the received data to.
-file path
This option specifies that the destination of the data is a
file, and its associated argument is the path of the file to
write the received data to.
-variable varname
This option specifies that the destination of the data is a
variable, and its associated argument contains the name of the
variable to write the received data to. The variable is assumed
to be global or namespaced, anchored at the global namespace.
-progress command
This option, if specified, defines a command to be invoked for
each chunk of bytes received, allowing the user to monitor the
progress of the reception of the data. The callback is always
invoked with one additional argument, the number of bytes
received so far.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category transfer
of the Tcllib SF Trackers [http://source-
forge.net/tracker/?group_id=12883]. Please also report any ideas for
enhancements you may have for either package and/or documentation.
KEYWORDS
channel, copy, data destination, transfer
CATEGORY
Transfer module
COPYRIGHT
Copyright (c) 2006-2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>
transfer 0.2 transfer::data::destination(n)
Mac OS X 10.8 - Generated Thu Sep 6 05:39:29 CDT 2012