Ubuntu Manpage: transfer::data::destination

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

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DESCRIPTION

       This package provides objects mainly describing the destination of a data transfer. They are also able to
       initiate the reception of information from a channel into the described destination.

API

transfer::data::destination objectName ?options...?
This command creates a new data destination object with an associated Tcl command whose name is
objectName. This object command 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 behavior 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 neither 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 message describing the problem found
with the configuration. Otherwise 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 additional 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 configure 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 channel 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 Trackers [http://core.tcl.tk/tcllib/reportlist].
       Please also report any ideas for enhancements you may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note further that attachments are strongly preferred over inlined patches. Attachments  can  be  made  by
       going  to the Edit form of the ticket immediately after its creation, and then using the left-most button
       in the secondary navigation bar.

KEYWORDS

       channel, copy, data destination, transfer

COPYRIGHT

       Copyright (c) 2006-2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>

tcllib                                                 0.2                     transfer::data::destination(3tcl)