.\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{
.    if \nF \{
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
.    \" fudge factors for nroff and troff
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
.    \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    ds : e
.    ds 8 ss
.    ds o a
.    ds d- d\h'-1'\(ga
.    ds D- D\h'-1'\(hy
.    ds th \o'bp'
.    ds Th \o'LP'
.    ds ae ae
.    ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "Rose::Object::MixIn 3pm"
.TH Rose::Object::MixIn 3pm "2010-04-27" "perl v5.18.1" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
Rose::Object::MixIn \- A base class for mix\-ins.
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\&  package MyMixInClass;
\&
\&  use Rose::Object::MixIn(); # Use empty parentheses here
\&  our @ISA = qw(Rose::Object::MixIn);
\&
\&  _\|_PACKAGE_\|_\->export_tag(all => [ qw(my_cool_method my_other_method) ]);
\&
\&  sub my_cool_method  { ... }
\&  sub my_other_method { ... }
\&  ...
\&
\&  package MyClass;
\&  # Import methods my_cool_method() and my_other_method()
\&  use MyMixInClass qw(:all);
\&  ...
\&
\&  package MyOtherClass;  
\&  # Import just my_cool_method()
\&  use MyMixInClass qw(my_cool_method);
\&  ...
\&
\&  package YetAnotherClass;
\&  # Import just my_cool_method() as cool()
\&  use MyMixInClass { my_cool_method => \*(Aqcool\*(Aq }
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
Rose::Object::MixIn is a base class for mix-ins.  A mix-in is a class that exports methods into another class.  This export process is controlled with an Exporter\-like interface, but Rose::Object::MixIn does not inherit from Exporter.
.PP
When you use a Rose::Object::MixIn\-derived class, its import method is called at compile time.  In other words, this:
.PP
.Vb 1
\&    use Rose::Object::MixIn \*(Aqa\*(Aq, \*(Aqb\*(Aq, { c => \*(Aqd\*(Aq };
.Ve
.PP
is the same thing as this:
.PP
.Vb 1
\&    BEGIN { Rose::Object::MixIn\->import(\*(Aqa\*(Aq, \*(Aqb\*(Aq, { c => \*(Aqd\*(Aq }) }
.Ve
.PP
To prevent the import method from being run, put empty parentheses \*(L"()\*(R" after the package name instead of a list of arguments.
.PP
.Vb 1
\&    use Rose::Object::MixIn();
.Ve
.PP
See the synopsis for an example of when this is handy: using Rose::Object::MixIn from within a subclass.  Note that the empty parenthesis are important.  The following is \fInot\fR equivalent:
.PP
.Vb 2
\&    # This is not the same thing as the example above!
\&    use Rose::Object::MixIn;
.Ve
.PP
See the documentation for the import method below to learn what arguments it accepts.
.SH "CLASS METHODS"
.IX Header "CLASS METHODS"
.IP "\fBimport \s-1ARGS\s0\fR" 4
.IX Item "import ARGS"
Import the methods specified by \s-1ARGS\s0 into the package from which this method was called.  If the current class can already perform one of these methods, a fatal error will occur.  To override an existing method, you must use the \f(CW\*(C`\-force\*(C'\fR argument (see below).
.Sp
Valid formats for \s-1ARGS\s0 are as follows:
.RS 4
.IP "\(bu" 4
\&\fBA method name\fR
.Sp
Literal method names will be imported as-is.
.IP "\(bu" 4
\&\fBA tag name\fR
.Sp
Tags names are indicated with a leading colon.  For example, \*(L":all\*(R" specifies the \*(L"all\*(R" tag.  A tag is a stand-in for a list of methods.  See the export_tag method to learn how to create tags.
.IP "\(bu" 4
\&\fBA reference to a hash\fR
.Sp
Each key/value pair in this hash contains a method name and the name that it will be imported as.  Use this feature to import methods under different names in order to avoid conflicts with existing methods.
.IP "\(bu" 4
\&\f(CW\*(C`\-force\*(C'\fR
.Sp
The special literal argument \f(CW\*(C`\-force\*(C'\fR will cause the specified methods to be imported even if the calling class can already perform one or more of those methods.
.IP "\(bu" 4
\&\f(CW\*(C`\-target_class CLASS\*(C'\fR
.Sp
The special literal argument \f(CW\*(C`\-target\-class\*(C'\fR followed by a class name will cause the specified methods to be imported into \s-1CLASS\s0 rather than into the calling class.
.RE
.RS 4
.Sp
See the synopsis for several examples of the import method in action.  (Remember, it's called implicitly when you use a Rose::Object::MixIn\-derived class with anything other than an empty set of parenthesis \*(L"()\*(R" as an argument.)
.RE
.IP "\fBclear_export_tags\fR" 4
.IX Item "clear_export_tags"
Delete the entire list of export tags.
.IP "\fBexport_tag \s-1NAME\s0 [, \s-1ARRAYREF\s0]\fR" 4
.IX Item "export_tag NAME [, ARRAYREF]"
Get or set the list of method names associated with a tag.  The tag name should \fInot\fR begin with a colon.  If \s-1ARRAYREF\s0 is passed, then the list of methods associated with the specific tag is set.
.Sp
Returns a list (in list context) or a reference to an array (in scalar context) of method names.  The array reference return value should be treated as read-only.  If no such tag exists, and if an \s-1ARRAYREF\s0 is not passed, then a fatal error will occur.
.IP "\fBexport_tags\fR" 4
.IX Item "export_tags"
Returns a list (in list context) and a reference to an array (in scalar context) containing the complete list of export tags.  The array reference return value should be treated as read-only.
.SH "AUTHOR"
.IX Header "AUTHOR"
John C. Siracusa (siracusa@gmail.com)
.SH "LICENSE"
.IX Header "LICENSE"
Copyright (c) 2010 by John C. Siracusa.  All rights reserved.  This program is
free software; you can redistribute it and/or modify it under the same terms
as Perl itself.