1transfer::data::destination(Dna)ta transfer facilititersansfer::data::destination(n)
2______________________________________________________________________________
6
8 transfer::data::destination - Data destination
9
11 package require Tcl 8.4
12 package require snit ?1.0?
14 package require transfer::data::destination ?0.2?
16 transfer::data::destination objectName ?options...?
18 objectName method ?arg arg ...?
20 objectName destroy
22 objectName put chunk
24 objectName done
26 objectName valid msgvar
28 objectName receive channel done
30______________________________________________________________________________
32
34 This package provides objects mainly describing the destination of a
35 data transfer. They are also able to initiate the reception of informa‐
36 tion from a channel into the described destination.
37
39 transfer::data::destination objectName ?options...?
40 This command creates a new data destination object with an asso‐
41 ciated Tcl command whose name is objectName. This object com‐
42 mand is explained in full detail in the sections Object command
43 and Object methods. The set of supported options is explained in
44 section Options.
45 The object command will be created under the current namespace
47 if the objectName is not fully qualified, and in the specified
48 namespace otherwise. The fully qualified name of the object
49 command is returned as the result of the command.
50 OBJECT COMMAND
52 All objects created by the ::transfer::data::destination command have
53 the following general form:
54 objectName method ?arg arg ...?
56 The method method and its arg'uments determine the exact behav‐
57 ior of the command. See section Object methods for the detailed
58 specifications.
59 OBJECT METHODS
61 objectName destroy
62 This method destroys the object. Doing so while the object is
63 busy with the reception of information from a channel will cause
64 errors later on, when the reception completes and tries to ac‐
65 cess the now missing data structures of the destroyed object.
66 objectName put chunk
68 The main receptor method. Saves the received chunk of data into
69 the configured destination. It has to be called for each piece
70 of data received.
71 objectName done
73 The secondary receptor method. Finalizes the receiver. It has to
74 be called when the receiving channel signals EOF. Afterward nei‐
75 ther itself nor method put can be called anymore.
76 objectName valid msgvar
78 This method checks the configuration of the object for validity.
79 It returns a boolean flag as result, whose value is True if the
80 object is valid, and False otherwise. In the latter case the
81 variable whose name is stored in msgvar is set to an error mes‐
82 sage describing the problem found with the configuration. Other‐
83 wise this variable is not touched.
84 objectName receive channel done
86 This method initiates the reception of data from the specified
87 channel. The received data will be stored into the configured
88 destination, via calls to the methods put and done. When the
89 reception completes the command prefix done is invoked, with the
90 number of received characters appended to it as the sole addi‐
91 tional argument.
92 OPTIONS
94 All data destinations support the options listed below. It should be
95 noted that all are semi-exclusive, each specifying a different type of
96 destination and associated information. If these options are specified
97 more than once then the last option specified is used to actually con‐
98 figure the object.
99 -channel handle
101 This option specifies that the destination of the data is a
102 channel, and its associated argument is the handle of the chan‐
103 nel to write the received data to.
104 -file path
106 This option specifies that the destination of the data is a
107 file, and its associated argument is the path of the file to
108 write the received data to.
109 -variable varname
111 This option specifies that the destination of the data is a
112 variable, and its associated argument contains the name of the
113 variable to write the received data to. The variable is assumed
114 to be global or namespaced, anchored at the global namespace.
115 -progress command
117 This option, if specified, defines a command to be invoked for
118 each chunk of bytes received, allowing the user to monitor the
119 progress of the reception of the data. The callback is always
120 invoked with one additional argument, the number of bytes re‐
121 ceived so far.
122
124 This document, and the package it describes, will undoubtedly contain
125 bugs and other problems. Please report such in the category transfer
126 of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
127 also report any ideas for enhancements you may have for either package
128 and/or documentation.
129 When proposing code changes, please provide unified diffs, i.e the out‐
131 put of diff -u.
132 Note further that attachments are strongly preferred over inlined
134 patches. Attachments can be made by going to the Edit form of the
135 ticket immediately after its creation, and then using the left-most
136 button in the secondary navigation bar.
137
139 channel, copy, data destination, transfer
140
142 Transfer module
143
145 Copyright (c) 2006-2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>
146tcllib 0.2 transfer::data::destination(n)