'\"
'\" Generated from file 'ddest\&.man' by tcllib/doctools with format 'nroff'
'\" Copyright (c) 2006-2009 Andreas Kupries <andreas_kupries@users\&.sourceforge\&.net>
'\"
.TH "transfer::data::destination" n 0\&.3 tcllib "Data transfer facilities"
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.SH NAME
transfer::data::destination \- Data destination
.SH SYNOPSIS
package require \fBTcl 8\&.5 9\fR
.sp
package require \fBsnit ?1\&.0?\fR
.sp
package require \fBtransfer::data::destination ?0\&.3?\fR
.sp
\fBtransfer::data::destination\fR \fIobjectName\fR ?\fIoptions\fR\&.\&.\&.?
.sp
\fIobjectName\fR \fBmethod\fR ?\fIarg arg \&.\&.\&.\fR?
.sp
\fIobjectName\fR \fBdestroy\fR
.sp
\fIobjectName\fR \fBput\fR \fIchunk\fR
.sp
\fIobjectName\fR \fBdone\fR
.sp
\fIobjectName\fR \fBvalid\fR \fImsgvar\fR
.sp
\fIobjectName\fR \fBreceive\fR \fIchannel\fR \fIdone\fR
.sp
.BE
.SH DESCRIPTION
.PP
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\&.
.SH API
.TP
\fBtransfer::data::destination\fR \fIobjectName\fR ?\fIoptions\fR\&.\&.\&.?
This command creates a new data destination object with an associated
Tcl command whose name is \fIobjectName\fR\&.
This \fIobject\fR command is explained in full detail in the sections
\fBObject command\fR and \fBObject methods\fR\&. The set of
supported \fIoptions\fR is explained in section \fBOptions\fR\&.
.sp
The object command will be created under the current namespace if the
\fIobjectName\fR 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\&.
.PP
.SS "OBJECT COMMAND"
All objects created by the \fB::transfer::data::destination\fR command
have the following general form:
.TP
\fIobjectName\fR \fBmethod\fR ?\fIarg arg \&.\&.\&.\fR?
The method \fBmethod\fR and its \fIarg\fR'uments determine the
exact behavior of the command\&.
See section \fBObject methods\fR for the detailed
specifications\&.
.PP
.SS "OBJECT METHODS"
.TP
\fIobjectName\fR \fBdestroy\fR
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\&.
.TP
\fIobjectName\fR \fBput\fR \fIchunk\fR
The main receptor method\&. Saves the received \fIchunk\fR of data into
the configured destination\&. It has to be called for each piece of data
received\&.
.TP
\fIobjectName\fR \fBdone\fR
The secondary receptor method\&. Finalizes the receiver\&. It has to be
called when the receiving channel signals EOF\&. Afterward neither
itself nor method \fBput\fR can be called anymore\&.
.TP
\fIobjectName\fR \fBvalid\fR \fImsgvar\fR
This method checks the configuration of the object for validity\&. It
returns a boolean flag as result, whose value is \fBTrue\fR if the
object is valid, and \fBFalse\fR otherwise\&. In the latter case the
variable whose name is stored in \fImsgvar\fR is set to an error
message describing the problem found with the configuration\&. Otherwise
this variable is not touched\&.
.TP
\fIobjectName\fR \fBreceive\fR \fIchannel\fR \fIdone\fR
This method initiates the reception of data from the specified
\fIchannel\fR\&. The received data will be stored into the configured
destination, via calls to the methods \fBput\fR and \fBdone\fR\&.
When the reception completes the command prefix \fIdone\fR is invoked,
with the number of received characters appended to it as the sole
additional argument\&.
.PP
.SS 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\&.
.TP
\fB-channel\fR \fIhandle\fR
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\&.
.TP
\fB-file\fR \fIpath\fR
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\&.
.TP
\fB-variable\fR \fIvarname\fR
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\&.
.TP
\fB-progress\fR \fIcommand\fR
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\&.
.PP
.SH "BUGS, IDEAS, FEEDBACK"
This document, and the package it describes, will undoubtedly contain
bugs and other problems\&.
Please report such in the category \fItransfer\fR of the
\fITcllib Trackers\fR [http://core\&.tcl\&.tk/tcllib/reportlist]\&.
Please also report any ideas for enhancements you may have for either
package and/or documentation\&.
.PP
When proposing code changes, please provide \fIunified diffs\fR,
i\&.e the output of \fBdiff -u\fR\&.
.PP
Note further that \fIattachments\fR are strongly preferred over
inlined patches\&. Attachments can be made by going to the \fBEdit\fR
form of the ticket immediately after its creation, and then using the
left-most button in the secondary navigation bar\&.
.SH KEYWORDS
channel, copy, data destination, transfer
.SH CATEGORY
Transfer module
.SH COPYRIGHT
.nf
Copyright (c) 2006-2009 Andreas Kupries <andreas_kupries@users\&.sourceforge\&.net>

.fi
