'\"
'\" Generated from file 'current\&.man' by tcllib/doctools with format 'nroff'
'\" Copyright (c) 2014-16 Stefan Sobernig <stefan\&.sobernig@wu\&.ac\&.at>, Gustaf Neumann <gustaf\&.neumann@wu\&.ac\&.at>; available under the Creative Commons Attribution 3\&.0 Austria license (CC BY 3\&.0 AT)\&.
'\"
.TH "nx::current" 3 2\&.4\&.0 current "NX API"
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.SH NAME
nx::current \- Return information about the method callstack
.SH SYNOPSIS
\fBcurrent\fR ?\fIoption\fR?
.sp
.BE
.SH DESCRIPTION
.TP
\fBcurrent\fR ?\fIoption\fR?
This introspection command provides information about various details,
to be identified using \fIoption\fR, on the callstack\&. The command is
invoked from a method body\&. If \fIoption\fR is not provided, \fBnx::current\fR will
default to option \fBobject\fR (see
below)\&. \fBnx::current\fR operates on the Tcl callstack and is aware
of NX-specific callstack and stackframe details\&. Except for the
options \fBcallinglevel\fR and \fBlevel\fR, calling \fBnx::current\fR outside
an NX object or method will result in an error\&. \fIoption\fR can be
any of the following:
.RS
.IP \(bu
\fBactivelevel\fR returns the actual callstack level which
calls into the currently executing method directly\&. This \fBactivelevel\fR might
correspond the \fBcallinglevel\fR, but this is not necessarily
the case\&. The \fBactivelevel\fR also includes
intermediate calls, such as \fBnx::next\fR invocations\&. The level is
reported as an absolute level number (# followed by a digit) to be
directly used as the first argument to \fBuplevel\fR or \fBupvar\fR\&.
.IP \(bu
\fBargs\fR returns the list of argument values passed into the currently executing method implementation\&.
.IP \(bu
\fBcalledclass\fR returns the name of the class that provides
the method implementation to which the intercepted method call is to be redirected (only available from within filter methods)\&.
.IP \(bu
\fBcalledmethod\fR returns the original method name
requested by intercepted method call (only available from within
filter methods)\&.
.IP \(bu
\fBcallingclass\fR returns the name of the class which
provides the method implementation calling into the currently
executing method\&. See also \fBcallingobject\fR\&.
.IP \(bu
\fBcallinglevel\fR resolves the callstack level of the
originating invocation of the currently executing method
implementation\&. Callstack levels introduced by method interception
(e\&.g\&., filters) and by method combination (\fBnx::next\fR) are
ignored\&. The level is reported as an absolute level number (\fB#\fR followed
by a digit) to be directly used as the first argument to \fBuplevel\fR
or \fBupvar\fR\&. See also \fBactivelevel\fR\&. If called outside NX,
\fB1\fR is returned (which is the default for \fBupvar\fR and \fBuplevel\fR)\&.
.IP \(bu
\fBcallingobject\fR returns the name of the object which is
calling into the currently executing method\&. See also \fBcallingclass\fR\&.
.IP \(bu
\fBclass\fR returns the name of the class providing the
currently executing method implementation\&. The returned
method-providing class may be different to the class of the current
object\&. If called from within a method implementation provided by the
current object itself, an empty string is returned\&.
.IP \(bu
\fBfilterreg\fR returns the object (class) on which the
currently executing method was registered as a filter method (only
available from within filter methods)\&.
.IP \(bu
\fBisnextcall\fR will return 1, if the currently executing
method implementation was invoked via \fBnx::next\fR; 0 otherwise\&.
.IP \(bu
\fBlevel\fR will return a number indicating the stack
level of the currently executed method or script, or an empty string when
executed outside an NX context (e\&.g\&., in a Tcl proc or a namespace
script)\&. The resulting value can be directly passed as \fIlevel\fR to
\fBinfo level\fR\&.
.IP \(bu
\fBmethod\fR returns the name of the currently executing
method\&. If an ensemble-method call, the name of the bottom-most
("leaf") method is returned\&.
.IP \(bu
\fBmethodpath\fR returns the combined name of the
currently executing method (including all ensemble levels) in an
ensemble-method call\&. Otherwise, for a regular method call, the result
corresponds to the result of option \fBmethod\fR\&.
.IP \(bu
\fBnextmethod\fR returns the name of the next most
specific method implementation to be called when invoking \fBnx::next\fR\&.
.IP \(bu
\fBobject\fR gives the name of the object on which the
currently executing method implementation is evaluated\&.
.RE
.PP
.SH COPYRIGHT
.nf
Copyright (c) 2014-16 Stefan Sobernig <stefan\&.sobernig@wu\&.ac\&.at>, Gustaf Neumann <gustaf\&.neumann@wu\&.ac\&.at>; available under the Creative Commons Attribution 3\&.0 Austria license (CC BY 3\&.0 AT)\&.

.fi