[comment {-*- tcl -*- observe manpage}]
[manpage_begin observe n 2.5]
[copyright {Jeffrey Hobbs <jeff at hobbs.org>}]
[moddesc   {TkCon}]
[titledesc {Runtime debugging output in TkCon}]

[description]
[para]
This command provides runtime debugging output for variables
and commands without the need to edit your code.
For variables, the underlying mechanism uses [cmd trace] and [cmd dump] var.
For commands, it renames the observed procedure and uses a
special wrapper procedure.
WARNING: using this procedure after checkpointing state will
result in major problems if you clean state because the
renamed (true) commands will be lost.

[para]
This procedure is experimental.
Comments are encouraged.

[list_begin definitions]

[call [cmd observe] [arg command] [arg cmdname] [opt [arg maxlevel]]]
This will create a wrapper command which prints out (using [cmd dump])
the call stack to the console.
maxlevel represents the maximum number of levels of the call
stack which will be printed (defaults to 4).

[call [cmd observe] [arg cdelete] [arg cmdname]]
Removes the wrapper around an observed command.

[call [cmd observe] [arg cinfo] [arg cmdname]]
Prints out useless info.

[call [cmd observe] [arg variable] [arg varname] [arg operation] [opt [arg args]]]
Currently a wrapper around trace that uses [cmd dump] to print out
the value of the named variable whenever the specified
operation on that variable occurs (must be [arg read], [arg write] or [arg unset]).

[call [cmd observe] [arg vdelete] [arg varname] [arg operation]]
Deletes the trace wrapper around the named variable.

[call [cmd observe] [arg vinfo] [arg varname]]
Prints out trace info about the named variable.

[list_end]

[see_also [cmd tkcon](1)]
[see_also [cmd tkconrc](5) [cmd tkcon](n) [cmd dump](n)]
[see_also [cmd idebug](n)]
[keywords Tk console debug]

[manpage_end]