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6 Class::MakeMethods::Standard::Universal - Generic Methods
7
9 package MyObject;
10 use Class::MakeMethods::Standard::Universal (
11 no_op => 'this',
12 abstract => 'that',
13 delegate => { name=>'play_music', target=>'instrument', method=>'play' },
14 );
15
17 The Standard::Universal suclass of MakeMethods provides a [INCOMPLETE].
18
19 Calling Conventions
20 When you "use" this package, the method names you provide as arguments
21 cause subroutines to be generated and installed in your module.
22
23 See "Calling Conventions" in Class::MakeMethods::Standard for more
24 information.
25
26 Declaration Syntax
27 To declare methods, pass in pairs of a method-type name followed by one
28 or more method names.
29
30 Valid method-type names for this package are listed in "METHOD
31 GENERATOR TYPES".
32
33 See "Declaration Syntax" in Class::MakeMethods::Standard and "Parameter
34 Syntax" in Class::MakeMethods::Standard for more information.
35
37 no_op - Placeholder
38 For each method name passed, returns a subroutine with the following
39 characteristics:
40
41 · Does nothing.
42
43 You might want to create and use such methods to provide hooks for
44 subclass activity.
45
46 Sample declaration and usage:
47
48 package MyObject;
49 use Class::MakeMethods::Standard::Universal (
50 no_op => 'whatever',
51 );
52 ...
53
54 # Doesn't do anything
55 MyObject->whatever();
56
57 abstract - Placeholder
58 For each method name passed, returns a subroutine with the following
59 characteristics:
60
61 · Fails with an error message.
62
63 This is intended to support the use of abstract methods, that must be
64 overidden in a useful subclass.
65
66 If each subclass is expected to provide an implementation of a given
67 method, using this abstract method will replace the generic error
68 message below with the clearer, more explicit error message that
69 follows it:
70
71 Can't locate object method "foo" via package "My::Subclass"
72 The "foo" method is abstract and can not be called on My::Subclass
73
74 However, note that the existence of this method will be detected by
75 UNIVERSAL::can(), so it is not suitable for use in optional interfaces,
76 for which you may wish to be able to detect whether the method is
77 supported or not.
78
79 Sample declaration and usage:
80
81 package MyObject;
82 use Class::MakeMethods::Standard::Universal (
83 abstract => 'whatever',
84 );
85 ...
86
87 package MySubclass;
88 sub whatever { ... }
89
90 # Failure
91 MyObject->whatever();
92
93 # Success
94 MySubclass->whatever();
95
96 call_methods - Call methods by name
97 For each method name passed, returns a subroutine with the following
98 characteristics:
99
100 · Accepts a hash of key-value pairs, or a reference to hash of such
101 pairs. For each pair, the key is interpreted as the name of a
102 method to call, and the value is the argument to be passed to that
103 method.
104
105 Sample declaration and usage:
106
107 package MyObject;
108 use Class::MakeMethods::Standard::Universal (
109 call_methods => 'init',
110 );
111 ...
112
113 my $object = MyObject->new()
114 $object->init( foo => 'Foozle', bar => 'Barbados' );
115
116 # Equivalent to:
117 $object->foo('Foozle');
118 $object->bar('Barbados');
119
120 join_methods - Concatenate results of other methods
121 For each method name passed, returns a subroutine with the following
122 characteristics:
123
124 · Has a list of other methods names as an arrayref in the 'methods'
125 parameter. Required.
126
127 · When called, calls each of the named method on itself, in order,
128 and returns the concatenation of their results.
129
130 · If a 'join' parameter is provided it is included between each
131 method result.
132
133 · If the 'skip_blanks' parameter is omitted, or is provided with a
134 true value, removes all undefined or empty-string values from the
135 results.
136
137 alias - Call another method
138 For each method name passed, returns a subroutine with the following
139 characteristics:
140
141 · Calls another method on the same callee.
142
143 You might create such a method to extend or adapt your class'
144 interface.
145
146 Sample declaration and usage:
147
148 package MyObject;
149 use Class::MakeMethods::Standard::Universal (
150 alias => { name=>'click_here', target=>'complex_machinery' }
151 );
152 sub complex_machinery { ... }
153 ...
154
155 $myobj->click_here(...); # calls $myobj->complex_machinery(...)
156
157 delegate - Use another object to provide method
158 For each method name passed, returns a subroutine with the following
159 characteristics:
160
161 · Calls a method on self to retrieve another object, and then calls a
162 method on that object and returns its value.
163
164 You might want to create and use such methods to faciliate composition
165 of objects from smaller objects.
166
167 Sample declaration and usage:
168
169 package MyObject;
170 use Class::MakeMethods::Standard::Universal (
171 'Standard::Hash:object' => { name=>'instrument' },
172 delegate => { name=>'play_music', target=>'instrument', method=>'play' }
173 );
174 ...
175
176 my $object = MyObject->new();
177 $object->instrument( MyInstrument->new );
178 $object->play_music;
179
181 See Class::MakeMethods for general information about this distribution.
182
183 See Class::MakeMethods::Standard for more about this family of
184 subclasses.
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188perl v5.30.1 2020-01-29MakeMethods::Standard::Universal(3)