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## -------------------------------------------------------------------------------- |
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## $Id: Bridge.pm,v 1.10 2003/02/20 20:50:32 joko Exp $ |
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## -------------------------------------------------------------------------------- |
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## $Log: Bridge.pm,v $ |
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## Revision 1.10 2003/02/20 20:50:32 joko |
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## + small exception handling: now inheriting from little Exception object |
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## |
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## Revision 1.9 2003/02/18 18:35:30 joko |
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## + encapsulated/abstracted some more functionality: sub load_single |
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## |
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## Revision 1.8 2003/02/14 14:20:05 joko |
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## + modified mixin behaviour |
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## |
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## Revision 1.7 2003/02/11 10:34:19 joko |
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## + loaded module may now lack 'mixin::with' declaration |
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## + this gets us the possibility to load modules from any perl namespace |
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## + enabled this mechanism |
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## |
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## Revision 1.6 2003/02/09 16:22:51 joko |
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## + pseudo constructor mechanism via options |
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## |
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## Revision 1.5 2003/01/31 01:19:50 root |
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## + fixed: doesn't need Log::Dispatch any more, but uses it if available |
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## |
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## Revision 1.4 2003/01/20 16:55:15 joko |
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## + sub mixinPackage |
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## + sub include |
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## |
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## Revision 1.3 2002/12/16 19:57:12 joko |
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## + sub unload |
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## |
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## Revision 1.2 2002/12/15 02:06:15 joko |
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## + feature to be able to specify module in non-perl-style when loading plugins: e.g. $process->load('Setup/Storage') |
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## |
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## Revision 1.1 2002/12/13 21:46:29 joko |
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## + initial check-in |
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## |
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## -------------------------------------------------------------------------------- |
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|
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|
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package DesignPattern::Bridge; |
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|
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use strict; |
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use warnings; |
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|
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use base qw( |
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DesignPattern::Object |
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DesignPattern::Exception |
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); |
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|
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|
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use Data::Dumper; |
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|
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## ======== object inheritance ======== |
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|
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# TODO / REFACTORING PROPOSAL |
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# leading from Data::Storage to code abstracted out into this module - DesignPattern::Bridge |
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# - this is no inheritance and it doesn't have to be |
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# - implement this module as a bridge to its sub-modules |
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# - use the BridgePattern (http://c2.com/cgi/wiki?BridgePattern) |
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# Using patterns was already successfully done with Data::Storage::Handler |
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# by implementing the AdapterPattern (http://c2.com/cgi/wiki?AdapterPattern) |
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# with Perl's AUTOLOAD-mechanism |
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# - try to use Perl's "tie" command to implement this functionality here instead of using AUTOLOAD! |
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# - sub getChildNodes |
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# - sub run |
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|
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# 2003-02-11, joko: does this have anything in parallel with CPAN's Class::Inner? |
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|
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|
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# get logger instance |
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my $logger = eval { Log::Dispatch::Config->instance; }; |
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|
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my $meta; |
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|
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## ======== object constructor ======== |
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sub new { |
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my $invocant = shift; |
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my $class = ref($invocant) || $invocant; |
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my @args = (); |
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@_ && (@args = @_); |
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$logger->debug( __PACKAGE__ . "->new(@args)" ) if $logger; |
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my $self = { @_ }; |
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|
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# trace |
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#print "class: $class", "\n"; |
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|
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# create instance |
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bless $self, $class; |
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|
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return $self; |
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} |
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|
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|
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## ======== method overrider ======== |
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sub AUTOLOAD2 { |
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|
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my $self = shift; |
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our $AUTOLOAD; |
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|
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##print "AUTOLOAD\n"; |
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|
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my $method = $AUTOLOAD; |
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$method =~ s/^.*:://; |
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|
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$logger->debug( __PACKAGE__ . "->" . $method . "(@_)" . " (AUTOLOAD called, not dispatched)" ) if $logger; |
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|
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## ->DESTROY would - if not declared - trigger an AUTOLOAD also |
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return if $method =~ m/::DESTROY$/; |
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|
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## if ($self->_filter_AUTOLOAD($method)) { |
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## $self->_accessStorage(); |
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## $self->{STORAGEHANDLE}->$method(@_); |
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## } |
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|
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} |
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|
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sub _getPluginPackage { |
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my $self = shift; |
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my $modulename_load = shift; |
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|
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# substitute slashes through double double-colons to load modules perl-style |
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$modulename_load =~ s/\//::/g; |
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|
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# build full package name |
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my $self_classname = ref $self; |
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# name |
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my $package = $modulename_load; |
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|
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# if package is absolute, cut away prefix ('/' or '::') |
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if ($package !~ s/^:://) { |
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# else: prefix with base classname if above name is relative (lacks of '/' or '::') |
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$package = $self_classname . '::' . $package |
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} |
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|
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return $package; |
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} |
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|
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sub load { |
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|
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my $self = shift; |
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my $modulename = shift; |
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my $options = shift; |
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|
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if (ref $modulename eq 'ARRAY') { |
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foreach (@$modulename) { |
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$self->load_single($_, $options); |
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} |
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} else { |
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$self->load_single($modulename, $options); |
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} |
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|
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} |
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|
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sub load_single { |
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|
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my $self = shift; |
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my $modulename_load = shift; |
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|
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my $options = shift; |
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|
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my $self_modulename = ref $self; |
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my $package = $self->_getPluginPackage($modulename_load); |
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|
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if ($meta->{loaded}->{$package}) { |
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return 1; |
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} |
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|
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#$logger->info( __PACKAGE__ . "->load: $package" ) if $logger; |
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#$logger->info( __PACKAGE__ . "->load: $self_modulename" ) if $logger; |
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$logger->debug( $self_modulename . "->load: $package\t[via " . __PACKAGE__ . "]" ) if $logger; |
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|
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# this is the module testing phase - use mixin doesn't seem to propagate errors by default |
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eval("use $package;"); |
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$self->checkExceptions(); |
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|
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=pod |
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if ($@) { |
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$meta->{loaded}->{$package} = 0; |
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# include caller information |
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my @caller = caller; |
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my $caller_msg = $caller[1] . ':' . $caller[2]; |
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my $msg = __PACKAGE__ . "->load: $@ ($caller_msg)"; |
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if ($logger) { |
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$logger->error($msg); |
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} else { |
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print $msg, "\n"; |
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} |
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} |
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=cut |
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|
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#print "ref-1: ", ref $self, "\n"; |
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#print "ref-2: ", ref $self::SUPER, "\n"; |
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|
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# V1: |
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#bless $self, $package; |
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|
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# V2: |
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$self->mixinPackage($package); |
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|
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if (my $method = $options->{method}) { |
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$self->$method(); |
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} |
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|
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return 1; |
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|
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} |
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|
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sub mixinPackage { |
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my $self = shift; |
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my $package = shift; |
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|
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# switch into foreign package and prepare for mixin |
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$self->mixin_prepare($package); |
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|
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# switch into local package (scope which uses DesignPattern::Bridge) and mixin plugin-module |
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$self->mixin_do($package); |
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|
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} |
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|
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# TODO: maybe refactor to DesignPattern::Object? what about the '$logger'? |
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sub mixin_prepare { |
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my $self = shift; |
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my $package = shift; |
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my $self_classname = ref $self; |
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eval("package $package; use mixin::with '$self_classname';"); |
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|
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# FIXME: --- this is redundant --- |
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if ($@) { |
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$meta->{loaded}->{$package} = 0; |
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$logger->error( __PACKAGE__ . "->load: $@" ) if $logger; |
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} else { |
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$meta->{loaded}->{$package} = 1; |
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} |
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# FIXME: --- this is redundant --- |
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|
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} |
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|
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sub mixin_do { |
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my $self = shift; |
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my $package = shift; |
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# switch into foreign package and mixin plugin-module |
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my $self_classname = ref $self; |
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eval("package $self_classname; use mixin '$package';"); |
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#eval("use mixin_all '$package';"); |
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|
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# FIXME: --- this is redundant --- |
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if ($@) { |
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$meta->{loaded}->{$package} = 0; |
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$logger->error( __PACKAGE__ . "->load: $@" ) if $logger; |
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} else { |
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$meta->{loaded}->{$package} = 1; |
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} |
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# FIXME: --- this is redundant --- |
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|
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} |
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|
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sub unload { |
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|
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my $self = shift; |
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my $modulename_unload = shift; |
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|
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my $package = $self->_getPluginPackage($modulename_unload); |
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|
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if ($meta->{loaded}->{$package}) { |
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$meta->{loaded}->{$package} = 0; |
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my $where = __PACKAGE__ . ':' . __LINE__; |
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$logger->debug( __PACKAGE__ . "->unload: FIXME: DESTROY object is not implemented at '$where'." ) if $logger; |
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} |
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|
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} |
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|
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|
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sub boot { |
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my $self = shift; |
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$self->_abstract_function('boot'); |
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} |
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|
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sub include { |
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my $self = shift; |
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my $includefile = shift; |
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my $package = shift; |
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|
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# pre-flight checks |
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if (!$includefile) { |
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$self->raiseException('Filename for inclusion was empty.'); |
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return; |
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} |
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|
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# go for it ... |
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eval("require '$includefile';"); |
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# ... and handle errors afterwards catching every message from perl itself ... |
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return if $self->checkExceptions(); |
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|
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# ... otherwise continue assuming everything is fine |
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$self->mixinPackage($package) if $package; |
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|
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} |
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|
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1; |
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__END__ |
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