Provided by: libconfig-model-perl_2.152-1_all 
NAME
Config::Model::Loader - Load serialized data into config tree
VERSION
version 2.152
SYNOPSIS
use Config::Model;
# define configuration tree object
my $model = Config::Model->new;
$model->create_config_class(
name => "Foo",
element => [
[qw/foo bar/] => {
type => 'leaf',
value_type => 'string'
},
]
);
$model ->create_config_class (
name => "MyClass",
element => [
[qw/foo bar/] => {
type => 'leaf',
value_type => 'string'
},
hash_of_nodes => {
type => 'hash', # hash id
index_type => 'string',
cargo => {
type => 'node',
config_class_name => 'Foo'
},
},
[qw/lista listb/] => {
type => 'list',
cargo => {type => 'leaf',
value_type => 'string'
}
},
],
) ;
my $inst = $model->instance(root_class_name => 'MyClass' );
my $root = $inst->config_root ;
# put data
my $steps = 'foo=FOO hash_of_nodes:fr foo=bonjour -
hash_of_nodes:en foo=hello
! lista=foo,bar lista:2=baz
listb:0=foo listb:1=baz';
$root->load( steps => $steps );
print $root->describe,"\n" ;
# name value type comment
# foo FOO string
# bar [undef] string
# hash_of_nodes <Foo> node hash keys: "en" "fr"
# lista foo,bar,baz list
# listb foo,baz list
# delete some data
$root->load( steps => 'lista~2' );
print $root->describe(element => 'lista'),"\n" ;
# name value type comment
# lista foo,bar list
# append some data
$root->load( steps => q!hash_of_nodes:en foo.=" world"! );
print $root->grab('hash_of_nodes:en')->describe(element => 'foo'),"\n" ;
# name value type comment
# foo "hello world" string
DESCRIPTION
This module is used directly by Config::Model::Node to load serialized configuration data
into the configuration tree.
Serialized data can be written by the user or produced by Config::Model::Dumper while
dumping data from a configuration tree.
CONSTRUCTOR
new
The constructor should be used only by Config::Model::Node.
Parameters:
start_node
node ref of the root of the tree (of sub-root) to start the load from. Stored as a
weak reference.
load string syntax
The string is made of the following items (also called "actions") separated by spaces.
These actions can be divided in 4 groups:
• navigation: moving up and down the configuration tree.
• list and hash operation: select, add or delete hash or list item (also known as "id"
items)
• leaf operation: select, modify or delecte leaf value
• annotation: modify or delete configuration annotation (aka comment)
navigation
- Go up one node
! Go to the root node of the configuration tree.
xxx Go down using "xxx" element. (For "node" type element)
/xxx Go up until the element "xxx" is found. This search can be combined with one of
the command specified below, e.g "/a_string="foo bar""
list and hash operation
xxx:yy
Go down using "xxx" element and id "yy" (For "hash" or "list" element with "node"
cargo_type). Literal "\n" are replaced by real "\n" (LF in Unix).
xxx:.foreach_match(yy) or xxx:~yy
Go down using "xxx" element and loop over the ids that match the regex specified by
"yy". (For "hash").
For instance, with "OpenSsh" model, you could do
Host:~"/.*.debian.org/" user='foo-guest'
to set "foo-user" users for all your debian accounts.
The leading and trailing '/' may be omitted. Be sure to surround the regexp with
double quote if space are embedded in the regex.
Note that the loop ends when the load command goes above the element where the loop is
executed. For instance, the instruction below tries to execute "DX=BV" and "int_v=9"
for all elements of "std_id" hash:
std_id:~/^\w+$/ DX=Bv int_v=9
In the examples below only "DX=BV" is executed by the loop:
std_id:~/^\w+$/ DX=Bv - int_v=9
std_id:~/^\w+$/ DX=Bv ! int_v=9
The loop is done on all elements of the hash when no value is passed after "":~""
(mnemonic: an empty regexp matches any value).
xxx:.rm(yy) or xxx:-yy
Delete item referenced by "xxx" element and id "yy". For a list, this is equivalent to
"splice xxx,yy,1". This command does not go down in the tree (since it has just
deleted the element). I.e. a '"-"' is generally not needed afterwards.
xxx:.rm_value(yy) or xxx:-=yy
Remove the element whose value is "yy". For list or hash of leaves. Does not not
complain if the value to delete is not found.
xxx:..rm_match(yy) or xxx:-~/yy/
Remove the element whose value matches "yy". For list or hash of leaves. Does not not
complain if no value were deleted.
xxx:.substitute(/yy/zz/) or xxx:=~s/yy/zz/
Substitute a value with another. Perl switches can be used(e.g. "xxx:=~s/yy/zz/gi")
xxx:<yy or xxx:.push(yy)
Push "yy" value on "xxx" list
xxx:>yy or xxx:.unshift(yy)
Unshift "yy" value on "xxx" list
xxx:@ or xxx:.sort
Sort the list
xxx:.insert_at(yy,zz)
Insert "zz" value on "xxx" list before index "yy".
xxx:.insert_before(yy,zz)
Insert "zz" value on "xxx" list before value "yy".
xxx:.insert_before(/yy/,zz)
Insert "zz" value on "xxx" list before value matching "yy".
xxx:.insort(zz)
Insert "zz" value on "xxx" list so that existing alphanumeric order is preserved.
xxx:.insort(zz)
For hash element containing nodes: creates a new hash element with "zz" key on "xxx"
hash so that existing alphanumeric order of keys is preserved. Note that all keys are
sorted once this instruction is called. Following instructions are applied on the
created element. I.e. putting key order aside, "xxx:.insort(zz)" has the same effect
as "xxx:zz" instruction.
xxx:.insort(zz,vv)
For hash element containing leaves: creates a new hash element with "zz" key and
assing value "vv" so that existing alphanumeric order of keys is preserved. Note that
all keys are sorted once this instruction is called. Putting key order aside,
"xxx:.insort(zz,vv)" has the same effect as "xxx:zz=vv" instruction.
xxx:.ensure(zz)
Ensure that list "xxx" contains value "zz". If value "zz" is already stored in "xxx"
list, this function does nothing. In the other case, value "zz" is inserted in
alphabetical order.
xxx:=z1,z2,z3
Set list element "xxx" to list "z1,z2,z3". Use ",," for undef values, and "" for empty
values.
I.e, for a list "('a',undef,'','c')", use "a,,"",c".
xxx:yy=zz
For "hash" element containing "leaf" cargo_type. Set the leaf identified by key "yy"
to value "zz".
Using "xxx:~/yy/=zz" is also possible.
xxx:.copy(yy,zz)
copy item "yy" in "zz" (hash or list).
xxx:.json("path/to/file.json/foo/bar")
Store "bar" content in array or hash. This should be used to store hash or list of
values.
You may store deep data structure. In this case, make sure that the structure of the
loaded data matches the structure of the model. This won't happen by chance.
xxx:.clear
Clear the hash or list.
leaf operation
xxx=zz
Set element "xxx" to value "yy". load also accepts to set elements with a quoted
string. (For "leaf" element) Literal "\n" are replaced by real "\n" (LF in Unix).
Literal "\\" are replaced by "\".
For instance "foo="a quoted string"" or "foo="\"bar\" and \"baz\""".
xxx=~s/foo/bar/
Apply the substitution to the value of xxx. "s/foo/bar/" is the standard Perl "s"
substitution pattern.
Patterns with white spaces must be surrounded by quotes:
xxx=~"s/foo bar/bar baz/"
Perl pattern modifiers are accepted
xxx=~s/FOO/bar/i
xxx~
Undef element "xxx"
xxx.=zzz
Appends "zzz" value to current value (valid for "leaf" elements).
xxx=.file(yyy)
Store the content of file "yyy" in element "xxx".
Store STDIn in value xxx when "yyy" is '-'.
xxx=.json(path/to/data.json/foo/bar)
Open file "data.json" and store value from JSON data extracted with "foo/bar" subpath.
For instance, if "data.json" contains:
{
"foo": {
"bar": 42
}
}
The instruction "baz=.json(data.json/foo/bar)" stores 42 in "baz" element.
xxx=.yaml(path/to/data.yaml/0/foo/bar)
Open file "data.yaml" and store value from YAML data extracted with "0/foo/bar"
subpath.
Since a YAML file can contain several documents (separated by "---" lines, the subpath
must begin with a number to select the document containing the required value.
For instance, if "data.yaml" contains:
---
foo:
bar: 42
The instruction "baz=.yaml(data.yaml/0/foo/bar)" stores 42 in "baz" element.
xxx=.env(yyy)
Store the content of environment variable "yyy" in element "xxx".
annotation
xxx#zzz or xxx:yyy#zzz
Element annotation. Can be quoted or not quoted. Note that annotations are always
placed at the end of an action item.
I.e. "foo#comment", "foo:bar#comment" or "foo:bar=baz#comment" are valid.
"foo#comment:bar" is not valid.
Quotes
You can surround indexes and values with double quotes. E.g.:
a_string="\"foo\" and \"bar\""
Examples
You can use cme to modify configuration with "cme modify" command.
For instance, if Config::Model::Ssh is installed, you can run:
cme modify ssh 'ControlMaster=auto ControlPath="~/.ssh/master-%r@%n:%p"'
To delete "Host *" entry:
cme modify ssh 'Host:-"*"'
To specify 2 "Host" with a single command:
cme modify ssh 'Host:"foo* bar*" ForwardX11=yes HostName="foo.com" - Host:baz HostName="baz.com"'
Note the '"-"' used to go up one node before ""Host:baz"". In this case, "up one node"
leads to the "root node", so ""!"" could also be used instead of ""-"":
cme modify ssh 'Host:"foo* bar*" ForwardX11=yes HostName="foo.com" ! Host:baz HostName="baz.com"'
Let's modify now the host name of using a ".org" domain instead of ".com". The ":~"
operator uses a regexp to loop over several Host entries:
cme modify ssh 'Host:~/ba[rz]/ HostName=~s/.com$/.org/'
Now that ssh config is mucked up with dummy entries, let's clean up:
cme modify ssh 'Host:-"baz" Host:-"foo* bar*"'
Methods
load
Load data into the node tree (from the node passed with "node") and fill values as we go
following the instructions passed with "steps". ("steps" can also be an array ref).
Parameters are:
steps (or step)
A string or an array ref containing the steps to load. See "load string syntax" in
above for a description of the string.
check
Whether to check values while loading. Either "yes" (default), "no" or "skip". Bad
values are discarded when "check" is set to "skip".
caller_is_root
Change the target of the "!" command: when set, the "!" command go to caller node
instead of going to root node. (default is false)
AUTHOR
Dominique Dumont, (ddumont at cpan dot org)
SEE ALSO
Config::Model,Config::Model::Node,Config::Model::Dumper
AUTHOR
Dominique Dumont
COPYRIGHT AND LICENSE
This software is Copyright (c) 2005-2022 by Dominique Dumont.
This is free software, licensed under:
The GNU Lesser General Public License, Version 2.1, February 1999