1Config::Model::Role::GrUasbe(r3)Contributed Perl DocumenCtoantfiiogn::Model::Role::Grab(3)
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NAME

6       Config::Model::Role::Grab - Role to grab data from elsewhere in the
7       tree
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VERSION

10       version 2.142
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SYNOPSIS

13         $root->grab('foo:2 bar');
14         $root->grab(steps => 'foo:2 bar');
15         $root->grab(steps => 'foo:2 bar', type => 'leaf');
16         $root->grab_value(steps => 'foo:2 bar');
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DESCRIPTION

19       Role used to let a tree item (i.e. node, hash, list or leaf) to grab
20       another item or value from the configuration tree using a path (a bit
21       like an xpath path with a different syntax).
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METHODS

24   grab
25       Grab an object from the configuration tree.
26
27       Parameters are:
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29       "steps" (or "step")
30           A string indicating the steps to follow in the tree to find the
31           required item. (mandatory)
32
33       "mode"
34           When set to "strict", "grab" throws an exception if no object is
35           found using the passed string. When set to "adaptative", the object
36           found last is returned. For instance, for the steps "good_step
37           wrong_step", only the object held by "good_step" is returned. When
38           set to "loose", grab returns undef in case of problem. (default is
39           "strict")
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41       "type"
42           Either "node", "leaf", "hash" or "list" or an array ref containing
43           these values. Returns only an object of requested type. Depending
44           on "strict" value, "grab" either throws an exception or returns the
45           last object found with the requested type.  (optional, default to
46           "undef", which means any type of object)
47
48           Examples:
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50            $root->grab(steps => 'foo:2 bar', type => 'leaf')
51            $root->grab(steps => 'foo:2 bar', type => ['leaf','check_list'])
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53       "autoadd"
54           When set to 1, "hash" or "list" configuration element are created
55           when requested by the passed steps. (default is 1).
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57       grab_non_available
58           When set to 1, grab returns an object even if this one is not
59           available. I.e. even if this element was warped out. (default is
60           0).
61
62       The "steps" parameters is made of the following items separated by
63       spaces:
64
65       -       Go up one node
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67       !       Go to the root node.
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69       !Foo    Go up the configuration tree until the "Foo" configuration
70               class is found. Raise an exception if no "Foo" class is found
71               when root node is reached.
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73       xxx     Go down using "xxx" element.
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75       xxx:yy  Go down using "xxx" element and id "yy" (valid for hash or list
76               elements)
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78       ?xxx    Go up the tree until a node containing element "xxx" is found.
79               Then go down the tree like item "xxx".
80
81               "?xxx:yy" goes up the tree the same way. But no check is done
82               to see if id "yy" key actually exists or not. Only the element
83               "xxx" is considered when going up the tree.
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85   grab_value
86       Like "grab", but returns the value of a leaf or check_list object, not
87       just the leaf object.
88
89       "grab_value" raises an exception if following the steps ends on
90       anything but a leaf or a check_list.
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92   grab_annotation
93       Like "grab", but returns the annotation of an object.
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95   grab_root
96       Returns the root of the configuration tree.
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98   grab_ancestor
99       Parameter: a configuration class name
100
101       Go up the configuration tree until a node using the configuration class
102       is found. Returns the found node or undef.
103
104       Example:
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106         # returns a Config::Model::Node object for a Systemd::Service config class
107         $self->grab('Systemd::Service');
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AUTHOR

110       Dominique Dumont
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113       This software is Copyright (c) 2005-2021 by Dominique Dumont.
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115       This is free software, licensed under:
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117         The GNU Lesser General Public License, Version 2.1, February 1999
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121perl v5.34.0                      2021-07-22      Config::Model::Role::Grab(3)
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