1Config::MVP::Assembler(U3s)er Contributed Perl DocumentatCioonnfig::MVP::Assembler(3)
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NAME

6       Config::MVP::Assembler - multivalue-property config-loading state
7       machine
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VERSION

10       version 2.200012
11

DESCRIPTION

13       First, you should probably read the example of using Config::MVP.  If
14       you already know how it works, keep going.
15
16       Config::MVP::Assembler is a helper for constructing a
17       Config::MVP::Sequence object.  It's a very simple state machine that
18       lets you signal what kind of events you've encountered while reading
19       configuration.
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ATTRIBUTES

22   sequence_class
23       This attribute stores the name of the class to be used for the
24       assembler's sequence.  It defaults to Config::MVP::Sequence.
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26   section_class
27       This attribute stores the name of the class to be used for sections
28       created by the assembler.  It defaults to Config::MVP::Section.
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30   sequence
31       This is the sequence that the assembler is assembling.  It defaults to
32       a new instance of the assembler's "sequence_class".
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METHODS

35   begin_section
36         $assembler->begin_section($package_moniker, $name);
37
38         $assembler->begin_section($package_moniker);
39
40         $assembler->begin_section( \$package );
41
42       This method tells the assembler that it should begin work on a new
43       section with the given identifier.  If it is already working on a
44       section, an error will be raised.  See "change_section" for a method to
45       begin a new section, ending the current one if needed.
46
47       The package moniker is expanded by the "expand_package" method.  The
48       name, if not given, defaults to the package moniker.  These data are
49       used to create a new section and the section is added to the end of the
50       sequence.  If the package argument is a reference, it is used as the
51       literal value for the package, and no expansion is performed.  If it is
52       a reference to undef, a section with no package is created.
53
54   end_section
55         $assembler->end_section;
56
57       This ends the current section.  If there is no current section, an
58       exception is raised.
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60   change_section
61         $assembler->change_section($package_moniker, $name);
62
63         $assembler->change_section($package_moniker);
64
65       This method calls "begin_section", first calling "end_section" if
66       needed.
67
68   add_value
69         $assembler->add_value( $name => $value );
70
71       This method tells the assembler that it has encountered a named value
72       and should add it to the current section.  If there is no current
73       section, an exception is raised.  (If this is not the first time we've
74       seen the name in the section and it's not a multivalue property, the
75       section class will raise an exception on its own.)
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77   expand_package
78       This method is passed a short identifier for a package and is expected
79       to return the full name of the module to load and package to
80       interrogate.  By default it simply returns the name it was passed,
81       meaning that package names must be given whole to the "change_section"
82       method.
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84   current_section
85       This returns the section object onto which the assembler is currently
86       adding values.  If no section has yet been created, this method will
87       return false.
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TYPICAL USE

90         my $assembler = Config::MVP::Assembler->new;
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92         # Maybe you want a starting section:
93         my $starting_section = $assembler->section_class->new({ name => '_' });
94         $assembler->sequence->add_section($section_starting);
95
96         # We'll add some values, which will go to the starting section:
97         $assembler->add_value(x => 10);
98         $assembler->add_value(y => 20);
99
100         # Change to a new section...
101         $assembler->change_section($moniker);
102
103         # ...and add values to that section.
104         $assembler->add_value(x => 100);
105         $assembler->add_value(y => 200);
106
107       The code above creates an assembler and populates it step by step.  In
108       the end, to get values, you could do something like this:
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110         my @output;
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112         for my $section ($assembler->sequence->sections) {
113           push @output, [ $section->name, $section->package, $section->payload ];
114         }
115
116       When changing sections, the given section "moniker" is used for the new
117       section name.  The result of passing that moniker to the assembler's
118       "expand_package" method is used as the section's package name.  (By
119       default, this method does nothing.)  The new section's
120       "multivalue_args" and "aliases" are determined by calling the
121       "mvp_multivalue_args" and "mvp_aliases" methods on the package.
122

AUTHOR

124       Ricardo Signes <rjbs@cpan.org>
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127       This software is copyright (c) 2021 by Ricardo Signes.
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129       This is free software; you can redistribute it and/or modify it under
130       the same terms as the Perl 5 programming language system itself.
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134perl v5.34.0                      2022-01-21         Config::MVP::Assembler(3)
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