Mozilla/mozilla/webtools/PLIF/PLIF/Controller.pm
ian%hixie.ch 441cd7e2bc Comment out the debug code in the DESTROY handler
git-svn-id: svn://10.0.0.236/trunk@140399 18797224-902f-48f8-a5cc-f745e15eee43
2003-03-27 19:52:23 +00:00

272 lines
9.1 KiB
Perl

# -*- Mode: perl; tab-width: 4; indent-tabs-mode: nil; -*-
#
# This file is MPL/GPL dual-licensed under the following terms:
#
# The contents of this file are subject to the Mozilla Public License
# Version 1.1 (the "License"); you may not use this file except in
# compliance with the License. You may obtain a copy of the License at
# http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS IS"
# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
# the License for the specific language governing rights and
# limitations under the License.
#
# The Original Code is PLIF 1.0.
# The Initial Developer of the Original Code is Ian Hickson.
#
# Alternatively, the contents of this file may be used under the terms
# of the GNU General Public License Version 2 or later (the "GPL"), in
# which case the provisions of the GPL are applicable instead of those
# above. If you wish to allow use of your version of this file only
# under the terms of the GPL and not to allow others to use your
# version of this file under the MPL, indicate your decision by
# deleting the provisions above and replace them with the notice and
# other provisions required by the GPL. If you do not delete the
# provisions above, a recipient may use your version of this file
# under either the MPL or the GPL.
package PLIF::Controller;
use strict;
use vars qw(@ISA);
use PLIF::Service;
use PLIF::MagicPipingArray;
use PLIF::MagicSelectingArray;
use PLIF::MagicCollectingArray;
@ISA = qw(PLIF::Service);
1;
__DATA__
# setup everything (typically called from the constructor)
sub init {
my $self = shift;
$self->SUPER::init(@_);
# prepare the services array for the registration system
$self->{services} = [];
$self->{objects} = [];
$self->{servicesHash} = {};
# perform the registration
$self->registerServices();
}
# should be called from the implementation of registerServices, should
# be passed a list similar to the @ISA list. The order matters, since
# services will be instantiated on a first-matched first-used basis
sub register {
my $self = shift;
foreach my $service (@_) {
push(@{$self->{services}}, $service);
my $file = $service;
# XXX THIS IS PLATFORM SPECIFIC CODE XXX
if ($^O eq 'linux') {
$file =~ s/::/\//go;
$file .= '.pm';
} else {
$self->error(0, "Platform '$^O' not supported yet.");
}
# XXX END OF PLATFORM SPECIFIC CODE XXX
eval {
require $file;
};
if ($@) {
$self->error(1, "Compile error in $file: $@");
}
}
}
# helper method for (e.g.) input verifiers to add instantiated service
# objects specific to the current state (e.g. the current user in an
# event loop). These should be wiped out when the state changes (e.g.
# at the start of an event loop).
#
# Objects should be created with $service->createObject(), not with
# $app->getServiceInstance(), because they end up calling different
# constructors -- init() vs objectInit().
sub addObject {
my $self = shift;
foreach my $object (@_) {
$self->assert(defined($object), 1, 'Internal error: Tried to add undefined object to object list.');
push(@{$self->{objects}}, $object);
}
}
sub removeObject {
my $self = shift;
# XXX for 5.6.1, use this:
# foreach my $object (@_) {
# foreach my $index (0..$#{$self->{objects}}) {
# if ($self->{objects}->[$index] == $object) {
# delete($self->{objects}->[$index]);
# }
# }
# }
# won't work in early perls though, so instead:
my $objects = [];
object: foreach my $object (@{$self->{objects}}) {
foreach my $removee (@_) {
if ($object == $removee) {
next object;
}
}
push(@$objects, $objects);
}
$self->{objects} = $objects;
}
sub getService {
my $self = shift;
my($name) = @_;
if (defined($self->{servicesHash}->{$name})) {
return $self->{servicesHash}->{$name};
}
foreach my $service (@{$self->{services}}) {
if ($service->provides($name)) {
# Create the service. If it is already created, this will
# just return the object reference, so no harm done.
# IT IS ABSOLUTELY IMPERATIVE THAT NO SERVICE EVER HOLD ON
# TO THE $self ARGUMENT PASSED TO THE CONSTRUCTOR!
# Doing so would create a circular dependency, resulting
# in a memory leak.
$service = $service->create($self);
$self->{servicesHash}->{$name} = $service;
return $service;
}
}
return undef;
}
sub getObject {
# same as getService but on the objects list and without the
# constructor call
my $self = shift;
my($name) = @_;
foreach my $object (@{$self->{objects}}) {
if ($object->objectProvides($name)) {
return $object;
}
}
return undef;
}
sub getServiceList {
my $self = shift;
my($name) = @_;
my @services = ();
foreach my $service (@{$self->{services}}) {
if ($service->provides($name)) {
# Create the service. If it is already created, this will
# just return the object reference, so no harm done.
# IT IS ABSOLUTELY IMPERATIVE THAT NO SERVICE EVER HOLD ON
# TO THE $self ARGUMENT PASSED TO THE CONSTRUCTOR!
# Doing so would create a circular dependency, resulting
# in a memory leak.
$service = $service->create($self);
push(@services, $service);
}
}
return @services;
}
sub getObjectList {
# same as getServiceList but on the objects list and without the
# constructor call
my $self = shift;
my($name) = @_;
my @objects = ();
foreach my $object (@{$self->{objects}}) {
if ($object->objectProvides($name)) {
push(@objects, $object);
}
}
return @objects;
}
sub getCollectingServiceList {
my $self = shift;
return PLIF::MagicCollectingArray->create($self->getServiceList(@_));
}
sub getCollectingObjectList {
my $self = shift;
return PLIF::MagicCollectingArray->create($self->getObjectList(@_));
}
sub getPipingServiceList {
my $self = shift;
return PLIF::MagicPipingArray->create($self->getServiceList(@_));
}
sub getPipingObjectList {
my $self = shift;
return PLIF::MagicPipingArray->create($self->getObjectList(@_));
}
sub getSelectingServiceList {
my $self = shift;
return PLIF::MagicSelectingArray->create($self->getServiceList(@_));
}
sub getSelectingObjectList {
my $self = shift;
return PLIF::MagicSelectingArray->create($self->getObjectList(@_));
}
sub getServiceInstance {
my $self = shift;
my($name, @data) = @_;
foreach my $service (@{$self->{services}}) {
if ($service->provides($name)) {
# Create and return the service instance, without storing
# a copy.
# This is the only time it is safe for a service to store
# a reference to us. This is because here no reference to
# the service is being held by us, so the moment the
# service goes out of scope, it will be freed.
# IMPORTANT! DON'T HOLD ON TO A SERVICE INSTANCE OBJECT!
return $service->serviceCreate($self, @data);
}
}
return undef;
}
# there's no getObjectInstance since objects already are instances...
# What is the difference between a service instance and an object? The
# difference is subtle. Objects are instances of classes that are
# intended to be added to the application's object list, they are
# created by invoking the 'createObject' method on a service, they
# initialize with 'objectInit' and not 'init', they are queried with
# 'objectProvides' and not 'provides'. On the other hand, service
# instances are services that are NOT intended to be kept in either of
# the controller's lists, they are created by the controller, and they
# are never asked for as normal services.
# unrelated to 'dispatch' from the service method, which only
# dispatches to the current object; this finds a service that supports
# the method and dispatches the call to them.
sub dispatchMethod {
my $self = shift;
my($service, $prefix, $method, @arguments) = @_;
# the \u makes the first letter of the $command uppercase
return ($self->getSelectingServiceList($service)->dispatch($self, "$prefix\u$method", @arguments) or
$self->getSelectingObjectList($service)->dispatch($self, "$prefix\u$method", @arguments));
}
# sub DESTROY {
# my $self = shift;
# $self->dump(10, 'At controller shutdown, there were ' .
# # I assume there will always be > 1 and so haven't bothered to special case the singular grammar
# scalar(@{$self->{services}}) .
# ' services registered, of which ' .
# scalar(keys(%{$self->{servicesHash}})) .
# ' had been placed in the services hash.');
# }
# Implementation Specific Methods
# These should be overriden by real programs
sub registerServices {} # stub