Config::General::Extended - Extended access to Config files
use Config::General;
$conf = Config::General->new(
-ConfigFile => 'configfile',
-ExtendedAccess => 1
);
This is an internal module which makes it possible to use object oriented
methods to access parts of your config file.
Normally you don't call it directly.
- configfile('filename')
- Set the filename to be used by save to
"filename". It returns the current configured filename if called
without arguments.
- obj('key')
- Returns a new object (of Config::General::Extended Class)
from the given key. Short example: Assume you have the following config:
<individual>
<martin>
age 23
</martin>
<joseph>
age 56
</joseph>
</individual>
<other>
blah blubber
blah gobble
leer
</other>
and already read it in using
Config::General::Extended::new(), then you can get a
new object from the "individual" block this way:
$individual = $conf->obj("individual");
Now if you call getall on $individual (just for
reference) you would get:
$VAR1 = (
martin => { age => 13 }
);
Or, here is another use:
my $individual = $conf->obj("individual");
foreach my $person ($conf->keys("individual")) {
$man = $individual->obj($person);
print "$person is " . $man->value("age") . " years old\n";
}
See the discussion on hash() and
value() below.
If the key from which you want to create a new object is empty, an empty
object will be returned. If you run the following on the above config:
$obj = $conf->obj("other")->obj("leer");
Then $obj will be empty, just like if you have had run this:
$obj = Config::General::Extended->new( () );
Read operations on this empty object will return nothing or even fail. But
you can use an empty object for creating a new config using write
operations, i.e.:
$obj->someoption("value");
See the discussion on AUTOLOAD METHODS below.
If the key points to a list of hashes, a list of objects will be returned.
Given the following example config:
<option>
name = max
</option>
<option>
name = bea
</option>
you could write code like this to access the list the OOP way:
my $objlist = $conf->obj("option");
foreach my $option (@{$objlist}) {
print $option->name;
}
Please note that the list will be returned as a reference to an array.
Empty elements or non-hash elements of the list, if any, will be
skipped.
- hash('key')
- This method returns a hash(if it is one!) from the
config which is referenced by "key". Given the sample config
above you would get:
my %sub_hash = $conf->hash("individual");
print Dumper(\%sub_hash);
$VAR1 = {
martin => { age => 13 }
};
- array('key')
- This the equivalent of hash()
mentioned above, except that it returns an array. Again, we use the sample
config mentioned above:
$other = $conf->obj("other");
my @blahs = $other->array("blah");
print Dumper(\@blahs);
$VAR1 = [ "blubber", "gobble" ];
- value('key')
- This method returns the scalar value of a given key. Given
the following sample config:
name = arthur
age = 23
you could do something like that:
print $conf->value("name") . " is " . $conf->value("age") . " years old\n";
You can use this method also to set the value of "key" to
something if you give over a hash reference, array reference or a scalar
in addition to the key. An example:
$conf->value("key", \%somehash);
# or
$conf->value("key", \@somearray);
# or
$conf->value("key", $somescalar);
Please note, that this method does not complain about existing values within
"key"!
- is_hash('key') is_array('key') is_scalar('key')
- As seen above, you can access parts of your current config
using hash, array or scalar methods. But you are right if you guess, that
this might become problematic, if for example you call
hash() on a key which is in real not a hash but a
scalar. Under normal circumstances perl would refuse this and die.
To avoid such behavior you can use one of the methods is_hash()
is_array() is_scalar() to check if the value of
"key" is really what you expect it to be.
An example(based on the config example from above):
if($conf->is_hash("individual") {
$individual = $conf->obj("individual");
}
else {
die "You need to configure a "individual" block!\n";
}
- exists('key')
- This method returns just true if the given key exists in
the config.
- keys('key')
- Returns an array of the keys under the specified
"key". If you use the example config above you could do that:
print Dumper($conf->keys("individual");
$VAR1 = [ "martin", "joseph" ];
If no key name was supplied, then the keys of the object itself will be
returned.
You can use this method in foreach loops as seen in an example
above(obj() ).
- delete('key')
- This method removes the given key and all associated data
from the internal hash structure. If 'key' contained data, then this data
will be returned, otherwise undef will be returned.
- find(@list)
- Given a list of nodes, ->find will search for a tree
that branches in just this way, returning the Config::General::Extended
object it finds at the bottom if it exists. You can also search partway
down the tree and ->find should return where you left off.
For example, given the values find (qw (A B C)) and the following
tree (</end> tags omitted for brevity):
<A>
<FOO>
...
<B>
<BAZ>
...
<C>
BAR = shoo
find() will find the object at C with the value
BAR = shoo and return it.
Another useful feature is implemented in this class using the
AUTOLOAD
feature of perl. If you know the keynames of a block within your config, you
can access to the values of each individual key using the method notation. See
the following example and you will get it:
We assume the following config:
<person>
name = Moser
prename = Peter
birth = 12.10.1972
</person>
Now we read it in and process it:
my $conf = Config::General::Extended->new("configfile");
my $person = $conf->obj("person");
print $person->prename . " " . $person->name . " is " . $person->age . " years old\n";
This notation supports only scalar values! You need to make sure, that the block
<person> does not contain any subblock or multiple identical
options(which will become an array after parsing)!
If you access a non-existent key this way, Config::General will croak an error.
You can turn this behavior off by setting
-StrictObjects to 0 or
"no". In this case undef will be returned.
Of course you can use this kind of methods for writing data too:
$person->name("Neustein");
This changes the value of the "name" key to "Neustein". This
feature behaves exactly like
value(), which means you can
assign hash or array references as well and that existing values under the
given key will be overwritten.
Copyright (c) 2000-2022 Thomas Linden
This library is free software; you can redistribute it and/or modify it under
the terms of the Artistic License 2.0.
none known yet.
Thomas Linden <tlinden |AT| cpan.org>
2.07