1Config::Model::WarpedNoUdsee(r3)Contributed Perl DocumenCtoantfiiogn::Model::WarpedNode(3)
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6 Config::Model::WarpedNode - Node that change config class properties
7
9 version 1.205
10
12 $model ->create_config_class
13 (
14 name => 'Class_with_one_changing_node',
15 element =>
16 [
17 tree_macro => {type => 'leaf',
18 value_type => 'enum',
19 choice => [qw/XY XZ mXY W/]
20 },
21 'a_warped_node'
23 => {
24 type => 'warped_node',
25 follow => '! tree_macro',
26 morph => 1,
27 rules => {
28 XY => { config_class_name => ['SlaveY'], },
29 mXY => {
30 config_class_name => 'SlaveY',
31 experience => 'intermediate'
32 },
33 XZ => { config_class_name => 'SlaveZ' }
34 }
35 },
36 'another_warped_node'
38 => {
39 type => 'warped_node',
40 follow => { tm => '! tree_macro'},
41 morph => 1,
42 rules => [
43 '$tm eq "XY"' => { config_class_name => ['SlaveY'], },
44 '$tm eq "mXY"' => {
45 config_class_name => 'SlaveY',
46 experience => 'intermediate'
47 },
48 '$tm eq "XZ"' => { config_class_name => 'SlaveZ' }
49 ]
50 },
51
53 This class provides a way to change dynamically the configuration class
54 (or some other properties) of a node. The changes are done according to
55 the model declaration.
56 This declaration will specify one (or several) leaf in the
58 configuration tree that will trigger the actual property change of the
59 warped node. This leaf is also refered as warp master.
60 When the warp master(s) value(s) changes, WarpedNode will create an
62 instance of the new class required by the warp master.
63 If the morph parameter is set, the values held by the old object are
65 (if possible) copied to the new instance of the object using copy_from
66 method.
67 Warped node can alter the following properties:
69 config_class_name
71 experience
72 level
73
75 WarpedNode should not be created directly.
76
78 Parameter overview
79 A warped node must be declared with the following parameters:
80 type
82 Always set to "warped_node".
83 follow
85 Grab string leading to the "Config::Model::Value" warp master. See
86 "Warp follow argument" in Config::Model::WarpedThing for details.
87 morph
89 boolean. If 1, WarpedNode will try to recursively copy the value
90 from the old object to the new object using copy_from method. When
91 a copy is not possible, undef values will be assigned to object
92 elements.
93 rules
95 Hash or array ref that specify the property change rules according
96 to the warp master(s) value(s). See "Warp rules argument" in
97 Config::Model::WarpedThing for details on how to specify the warp
98 master values (or combination of values).
99 Effect declaration
101 For a warped node, the effects are declared with these parameters:
102 config_class_name
104 When requested by the warp master,the WarpedNode will create a
105 new object of the type specified by this parameter:
106 XZ => { config_class_name => 'SlaveZ' }
108 If you pass an array ref, the array will contain the class name
110 and constructor arguments :
111 XY => { config_class_name => ['SlaveY', foo => 'bar' ], },
113 experience
115 Switch the experience of the slot when the object is warped in.
116
118 The following methods are forwared to contained node:
119 fetch_element config_class_name get_element_name has_element
121 is_element_available element_type load fetch_element_value get_type
122 get_cargo_type describe config_model
123
125 name
126 Return the name of the node (even if warped out).
127 is_accessible
129 Returns true if the node hidden behind this warped node is accessible,
130 i.e. the warp master have values so a node was warped in.
131 get_actual_node
133 Returns the node object hidden behind the warped node. Croaks if the
134 node is not accessible.
135 load_data ( hash_ref )
137 Load configuration data with a hash ref. The hash ref key must match
138 the available elements of the node carried by the warped node.
139
141 $model ->create_config_class
142 (
143 experience => [ bar => 'advanced'] ,
144 element =>
145 [
146 tree_macro => { type => 'leaf',
147 value_type => 'enum',
148 choice => [qw/XX XY XZ ZZ/]
149 },
150 bar => {
151 type => 'warped_node',
152 follow => '! tree_macro',
153 morph => 1,
154 rules => [
155 XX => { config_class_name
156 => [ 'ClassX', 'foo' ,'bar' ]}
157 XY => { config_class_name => 'ClassY'},
158 XZ => { config_class_name => 'ClassZ'}
159 ]
160 }
161 ]
162 );
163 In the example above we see that:
165 · The 'bar' slot can refer to a ClassX, ClassZ or ClassY object.
167 · The warper object is the "tree_macro" attribute of the root of the
169 object tree.
170 · When "tree_macro" is set to "ZZ", "bar" will not be available.
172 Trying to access bar will raise an exception.
173 · When "tree_macro" is changed from "ZZ" to "XX", "bar" will refer to
175 a brand new ClassX object constructed with "ClassX->new(foo =>
176 'bar')"
177 · Then, if "tree_macro" is changed from "XX" to "XY", "bar" will
179 refer to a brand new ClassY object. But in this case, the object
180 will be initialized with most if not all the attributes of ClassX.
181 This copy will be done whenever "tree_macro" is changed.
182
184 Dominique Dumont, (ddumont at cpan dot org)
185
187 Config::Model::Instance, Config::Model, Config::Model::HashId,
188 Config::Model::ListId, Config::Model::AnyThing,
189 Config::Model::WarpedThing, Config::Model::WarpedNode,
190 Config::Model::Value
191perl v5.12.1 2010-08-18 Config::Model::WarpedNode(3)