Config::MVP::AssemblerUser Contributed Perl DocumentaConfig::MVP::Assembler(3)NAMEConfig::MVP::Assembler - multivalue-property config-loading state
machine
VERSION
version 2.200002
DESCRIPTION
First, you should probably read the example of using Config::MVP. If
you already know how it works, keep going.
Config::MVP::Assembler is a helper for constructing a
Config::MVP::Sequence object. It's a very simple state machine that
lets you signal what kind of events you've encountered while reading
configuration.
ATTRIBUTES
sequence_class
This attribute stores the name of the class to be used for the
assembler's sequence. It defaults to Config::MVP::Sequence.
section_class
This attribute stores the name of the class to be used for sections
created by the assembler. It defaults to Config::MVP::Section.
sequence
This is the sequence that the assembler is assembling. It defaults to
a new instance of the assembler's "sequence_class".
METHODS
begin_section
$assembler->begin_section($package_moniker, $name);
$assembler->begin_section($package_moniker);
$assembler->begin_section( \$package );
This method tells the assembler that it should begin work on a new
section with the given identifier. If it is already working on a
section, an error will be raised. See "change_section" for a method to
begin a new section, ending the current one if needed.
The package moniker is expanded by the "expand_package" method. The
name, if not given, defaults to the package moniker. These data are
used to create a new section and the section is added to the end of the
sequence. If the package argument is a reference, it is used as the
literal value for the package, and no expansion is performed. If it is
a reference to undef, a section with no package is created.
end_section
$assembler->end_section;
This ends the current section. If there is no current section, an
exception is raised.
change_section
$assembler->change_section($package_moniker, $name);
$assembler->change_section($package_moniker);
This method calls "begin_section", first calling "end_section" if
needed.
add_value
$assembler->add_value( $name => $value );
This method tells the assembler that it has encountered a named value
and should add it to the current section. If there is no current
section, an exception is raised. (If this is not the first time we've
seen the name in the section and it's not a multivalue property, the
section class will raise an exception on its own.)
expand_package
This method is passed a short identifier for a package and is expected
to return the full name of the module to load and package to
interrogate. By default it simply returns the name it was passed,
meaning that package names must be given whole to the "change_section"
method.
current_section
This returns the section object onto which the assembler is currently
adding values. If no section has yet been created, this method will
return false.
TYPICAL USE
my $assembler = Config::MVP::Assembler->new;
# Maybe you want a starting section:
my $starting_section = $assembler->section_class->new({ name => '_' });
$assembler->sequence->add_section($section_starting);
# We'll add some values, which will go to the starting section:
$assembler->add_value(x => 10);
$assembler->add_value(y => 20);
# Change to a new section...
$assembler->change_section($moniker);
# ...and add values to that section.
$assembler->add_value(x => 100);
$assembler->add_value(y => 200);
The code above creates an assembler and populates it step by step. In
the end, to get values, you could do something like this:
my @output;
for my $section ($assembler->sequence->sections) {
push @output, [ $section->name, $section->package, $section->payload ];
}
When changing sections, the given section "moniker" is used for the new
section name. The result of passing that moniker to the assembler's
"expand_package" method is used as the section's package name. (By
default, this method does nothing.) The new section's
"multivalue_args" and "aliases" are determined by calling the
"mvp_multivalue_args" and "mvp_aliases" methods on the package.
AUTHOR
Ricardo Signes <rjbs@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2012 by Ricardo Signes.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
perl v5.14.2 2012-03-16 Config::MVP::Assembler(3)
