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Template::Stash(3)    User Contributed Perl Documentation   Template::Stash(3)

NAME
       Template::Stash - Magical storage for template variables

SYNOPSIS
	   use Template::Stash;

	   my $stash = Template::Stash->new(\%vars);

	   # get variable values
	   $value = $stash->get($variable);
	   $value = $stash->get(\@compound);

	   # set variable value
	   $stash->set($variable, $value);
	   $stash->set(\@compound, $value);

	   # default variable value
	   $stash->set($variable, $value, 1);
	   $stash->set(\@compound, $value, 1);

	   # set variable values en masse
	   $stash->update(\%new_vars)

	   # methods for (de-)localising variables
	   $stash = $stash->clone(\%new_vars);
	   $stash = $stash->declone();

DESCRIPTION
       The "Template::Stash" module defines an object class which is used to
       store variable values for the runtime use of the	template processor.
       Variable	values are stored internally in	a hash reference (which	itself
       is blessed to create the	object)	and are	accessible via the get() and
       set() methods.

       Variables may reference hash arrays, lists, subroutines and objects as
       well as simple values.  The stash automatically performs	the right
       magic when dealing with variables, calling code or object methods,
       indexing	into lists, hashes, etc.

       The stash has clone() and declone() methods which are used by the
       template	processor to make temporary copies of the stash	for localising
       changes made to variables.

PUBLIC METHODS
   new(\%params)
       The "new()" constructor method creates and returns a reference to a new
       "Template::Stash" object.

	   my $stash = Template::Stash->new();

       A hash reference	may be passed to provide variables and values which
       should be used to initialise the	stash.

	   my $stash = Template::Stash->new({ var1 => 'value1',
					      var2 => 'value2' });

   get($variable)
       The "get()" method retrieves the	variable named by the first parameter.

	   $value = $stash->get('var1');

       Dotted compound variables can be	retrieved by specifying	the variable
       elements	by reference to	a list.	 Each node in the variable occupies
       two entries in the list.	 The first gives the name of the variable
       element,	the second is a	reference to a list of arguments for that
       element,	or 0 if	none.

	   [% foo.bar(10).baz(20) %]

	   $stash->get([ 'foo',	0, 'bar', [ 10 ], 'baz', [ 20 ]	]);

   set($variable, $value, $default)
       The "set()" method sets the variable name in the	first parameter	to the
       value specified in the second.

	   $stash->set('var1', 'value1');

       If the third parameter evaluates	to a true value, the variable is set
       only if it did not have a true value before.

	   $stash->set('var2', 'default_value',	1);

       Dotted compound variables may be	specified as per get() above.

	   [% foo.bar =	30 %]

	   $stash->set([ 'foo',	0, 'bar', 0 ], 30);

       The magical variable '"IMPORT"' can be specified	whose corresponding
       value should be a hash reference.  The contents of the hash array are
       copied (i.e. imported) into the current namespace.

	   # foo.bar = baz, foo.wiz = waz
	   $stash->set('foo', {	'bar' => 'baz',	'wiz' => 'waz' });

	   # import 'foo' into main namespace: bar = baz, wiz =	waz
	   $stash->set('IMPORT', $stash->get('foo'));

   update($variables)
       This method can be used to set or update	several	variables in one go.

	   $stash->update({
	       foo => 10,
	       bar => 20,
	   });

   getref($variable)
       This undocumented feature returns a closure which can be	called to get
       the value of a variable.	 It is used to implement variable references
       which are evaluated lazily.

	   [% x	= \foo.bar.baz %]	   # x is a reference to foo.bar.baz
	   [% x	%]			   # evalautes foo.bar.baz

   clone(\%params)
       The "clone()" method creates and	returns	a new "Template::Stash"	object
       which represents	a localised copy of the	parent stash. Variables	can be
       freely updated in the cloned stash and when declone() is	called,	the
       original	stash is returned with all its members intact and in the same
       state as	they were before "clone()" was called.

       For convenience,	a hash of parameters may be passed into	"clone()"
       which is	used to	update any simple variable (i.e. those that don't
       contain any namespace elements like "foo" and "bar" but not "foo.bar")
       variables while cloning the stash.  For adding and updating complex
       variables, the set() method should be used after	calling	"clone()."
       This will correctly resolve and/or create any necessary namespace
       hashes.

       A cloned	stash maintains	a reference to the stash that it was copied
       from in its "_PARENT" member.

   declone()
       The "declone()" method returns the "_PARENT" reference and can be used
       to restore the state of a stash as described above.

   define_vmethod($type, $name,	$code)
       This method can be used to define new virtual methods.  The first
       argument	should be either "scalar" or "item" to define scalar virtual
       method, "hash" to define	hash virtual methods, or either	"array"	or
       "list" for list virtual methods.	 The second argument should be the
       name of the new method.	The third argument should be a reference to a
       subroutine implementing the method.  The	data item on which the virtual
       method is called	is passed to the subroutine as the first argument.

	   $stash->define_vmethod(
	       item => ucfirst => sub {
		   my $text = shift;
		   return ucfirst $text
	       }
	   );

INTERNAL METHODS
   dotop($root,	$item, \@args, $lvalue)
       This is the core	"dot" operation	method which evaluates elements	of
       variables against their root.

   undefined($ident, $args)
       This method is called when get()	encounters an undefined	value.	If the
       STRICT option is	in effect then it will throw an	exception indicating
       the use of an undefined value.  Otherwise it will silently return an
       empty string.

       The method can be redefined in a	subclass to implement alternate
       handling	of undefined values.

AUTHOR
       Andy Wardley <abw@wardley.org> <http://wardley.org/>

COPYRIGHT
       Copyright (C) 1996-2013 Andy Wardley.  All Rights Reserved.

       This module is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.

SEE ALSO
       Template, Template::Context

perl v5.32.1			  2020-07-13		    Template::Stash(3)

NAME | SYNOPSIS | DESCRIPTION | PUBLIC METHODS | INTERNAL METHODS | AUTHOR | COPYRIGHT | SEE ALSO

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