| Current File : //proc/self/root/usr/share/doc/perl-Template-Toolkit-2.24/modules/Template/Stash.html |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Strict//EN">
<html>
<head>
<title>Template::Stash</title>
<link rel="stylesheet" type="text/css" href="../../css/blue.css" title="Clear Blue">
<link rel="alternate stylesheet" type="text/css" href="../../css/orange.css" title="Clear Orange">
<link rel="alternate stylesheet" type="text/css" href="../../css/green.css" title="Clear Green">
<link rel="alternate stylesheet" type="text/css" href="../../css/purple.css" title="Clear Purple">
<link rel="alternate stylesheet" type="text/css" href="../../css/grey.css" title="Clear Grey">
<link rel="alternate stylesheet" type="text/css" href="../../css/print.css" title="Print">
<!--[if IE 6]>
<link rel="stylesheet" type="text/css" href="../../css/ie6.css" />
<![endif]-->
<!--[if IE 7]>
<link rel="stylesheet" type="text/css" href="../../css/ie7.css" />
<![endif]-->
<link rel="stylesheet" type="text/css" href="../../css/print.css" media="print">
<script type="text/javascript" src="../../js/tt2.js"></script>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<meta name="author" content="Andy Wardley">
</head>
<body id="body">
<div id="layout">
<div id="header">
<a href="../../index.html" id="logo" alt="" title="Click for the Home Page"><span class="alt">TT2 Home Page</span></a>
<ul id="trail">
<li><a href="../../modules/index.html">Modules</a></li>
<li><a href="../../modules/Template/index.html">Template::*</a></li>
<li class="last"><a href="../../modules/Template/Stash.html">Stash.pm</a></li>
</ul>
<div class="controls">
<a href="#" class="menu show" onclick="widescreen_off(); return false" title="Show Menu">
<span class="about">Click to view the menu. It's very nice.</span>
</a>
<a href="#" class="menu hide" onclick="widescreen_on(); return false" title="Hide Menu">
<span class="about">Click to hide the menu and go all widescreen!</span>
</a>
<div class="pager">
<a href="../../modules/Template/Service.html" title="Template::Service" class="go back">Back<span class="about"><h4>Template::Service</h4>General purpose template processing service</span></a>
<a href="../../modules/Template/index.html" title="Template::* Modules" class="go up">Up<span class="about"><h4>Template::* Modules</h4></span></a>
<a href="../../modules/Template/Stash/index.html" title="Template::Stash::* Modules" class="go next">Next<span class="about"><h4>Template::Stash::* Modules</h4></span></a>
</div>
</div>
<h1 class="headline">Template::Stash</h1>
<h2 class="subhead">Magical storage for template variables</h1>
</div>
<div id="page">
<div id="sidebar">
<a href="../../index.html" id="logo"></a>
<div id="menu">
<ul class="menu">
<li class="l0 first"><a href="../../manual/index.html">Manual</a></li>
<li class="l0"><a href="../../modules/index.html" class="warm">Modules</a></li>
<li class="l1"><a href="../../modules/Template.html">Template.pm</a></li>
<li class="l1"><a href="../../modules/Template/index.html" class="warm">Template::*</a></li>
<li class="l2"><a href="../../modules/Template/Base.html">Base.pm</a></li>
<li class="l2"><a href="../../modules/Template/Config.html">Config.pm</a></li>
<li class="l2"><a href="../../modules/Template/Constants.html">Constants.pm</a></li>
<li class="l2"><a href="../../modules/Template/Context.html">Context.pm</a></li>
<li class="l2"><a href="../../modules/Template/Directive.html">Directive.pm</a></li>
<li class="l2"><a href="../../modules/Template/Document.html">Document.pm</a></li>
<li class="l2"><a href="../../modules/Template/Exception.html">Exception.pm</a></li>
<li class="l2"><a href="../../modules/Template/Filters.html">Filters.pm</a></li>
<li class="l2"><a href="../../modules/Template/Grammar.html">Grammar.pm</a></li>
<li class="l2"><a href="../../modules/Template/Iterator.html">Iterator.pm</a></li>
<li class="l2"><a href="../../modules/Template/Namespace/index.html">Namespace::*</a></li>
<li class="l2"><a href="../../modules/Template/Parser.html">Parser.pm</a></li>
<li class="l2"><a href="../../modules/Template/Plugin.html">Plugin.pm</a></li>
<li class="l2"><a href="../../modules/Template/Plugin/index.html">Plugin::*</a></li>
<li class="l2"><a href="../../modules/Template/Plugins.html">Plugins.pm</a></li>
<li class="l2"><a href="../../modules/Template/Provider.html">Provider.pm</a></li>
<li class="l2"><a href="../../modules/Template/Service.html">Service.pm</a></li>
<li class="l2"><a href="../../modules/Template/Stash.html" class="warm">Stash.pm</a></li>
<li class="l2"><a href="../../modules/Template/Stash/index.html">Stash::*</a></li>
<li class="l2"><a href="../../modules/Template/Test.html">Test.pm</a></li>
<li class="l2"><a href="../../modules/Template/VMethods.html">VMethods.pm</a></li>
<li class="l2"><a href="../../modules/Template/View.html">View.pm</a></li>
<li class="l0"><a href="../../tools/index.html">Tools</a></li>
<li class="l0"><a href="../../tutorial/index.html">Tutorial</a></li>
<li class="l0 last"><a href="../../faq/index.html">FAQ</a></li>
</ul>
<div class="foot"></div>
</div>
</div>
<div id="content">
<div class="section">
<div class="head">
<h1 id="contents" onclick="switch_section(this)" title="Click title to show/hide section content.">Contents</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<ul class="toc">
<li class=""><a href="#SYNOPSIS">SYNOPSIS</a></li>
<li class=""><a href="#DESCRIPTION">DESCRIPTION</a></li>
<li class=""><a href="#PUBLIC_METHODS">PUBLIC METHODS</a></li>
<li class="sub"><a href="#method_new">new(\%params)</a></li>
<li class="sub"><a href="#method_get">get($variable)</a></li>
<li class="sub"><a href="#method_set">set($variable, $value, $default)</a></li>
<li class="sub"><a href="#method_update">update($variables)</a></li>
<li class="sub"><a href="#method_getref">getref($variable)</a></li>
<li class="sub"><a href="#method_clone">clone(\%params)</a></li>
<li class="sub"><a href="#method_declone">declone()</a></li>
<li class="sub"><a href="#method_define_vmethod">define_vmethod($type, $name, $code)</a></li>
<li class=""><a href="#INTERNAL_METHODS">INTERNAL METHODS</a></li>
<li class="sub"><a href="#method_dotop">dotop($root, $item, \@args, $lvalue)</a></li>
<li class="sub"><a href="#method_undefined">undefined($ident, $args)</a></li>
<li class=""><a href="#AUTHOR">AUTHOR</a></li>
<li class=""><a href="#COPYRIGHT">COPYRIGHT</a></li>
<li class=""><a href="#SEE_ALSO">SEE ALSO</a></li>
</ul>
</div>
</div>
<div class="pod">
<div class="section">
<div class="head">
<h1 id="SYNOPSIS" onclick="switch_section(this)" title="Click title to show/hide section content.">SYNOPSIS</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<pre>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();</pre>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="DESCRIPTION" onclick="switch_section(this)" title="Click title to show/hide section content.">DESCRIPTION</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The <code>Template::Stash</code> 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
<a href="#method_get">get()</a> and <a href="#method_set">set()</a>
methods.
</p>
<p>
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.
</p>
<p>
The stash has <a href="#method_clone">clone()</a> and <a
href="#method_declone">declone()</a> methods which are used by the
template processor to make temporary copies of the stash for localising
changes made to variables.
</p>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="PUBLIC_METHODS" onclick="switch_section(this)" title="Click title to show/hide section content.">PUBLIC METHODS</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<div class="subsection">
<div class="head">
<h2 id="method_new" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">new(\%params)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The <code>new()</code> constructor method creates and returns a reference
to a new <code>Template::Stash</code> object.
</p>
<pre>my $stash = Template::Stash->new();</pre>
<p>
A hash reference may be passed to provide variables and values which
should be used to initialise the stash.
</p>
<pre>my $stash = Template::Stash->new({ var1 => 'value1',
var2 => 'value2' });</pre>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_get" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">get($variable)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The <code>get()</code> method retrieves the variable named by the first
parameter.
</p>
<pre>$value = $stash->get('var1');</pre>
<p>
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
<code>0</code> if none.
</p>
<pre><span class="tt">[% foo.bar(10).baz(20) %]</span>
$stash->get([ 'foo', 0, 'bar', [ 10 ], 'baz', [ 20 ] ]);</pre>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_set" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">set($variable, $value, $default)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The <code>set()</code> method sets the variable name in the first
parameter to the value specified in the second.
</p>
<pre>$stash->set('var1', 'value1');</pre>
<p>
If the third parameter evaluates to a true value, the variable is set
only if it did not have a true value before.
</p>
<pre>$stash->set('var2', 'default_value', 1);</pre>
<p>
Dotted compound variables may be specified as per <a
href="#method_get">get()</a> above.
</p>
<pre><span class="tt">[% foo.bar = 30 %]</span>
$stash->set([ 'foo', 0, 'bar', 0 ], 30);</pre>
<p>
The magical variable '<code>IMPORT</code>' 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.
</p>
<pre># 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', $stash->get('foo'));</pre>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_update" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">update($variables)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
This method can be used to set or update several variables in one go.
</p>
<pre>$stash->update({
foo => 10,
bar => 20,
});</pre>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_getref" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">getref($variable)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
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 evlauted lazily.
</p>
<pre><span class="tt">[% x = \foo.bar.baz %]</span> # x is a reference to foo.bar.baz
<span class="tt">[% x %]</span> # evalautes foo.bar.baz</pre>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_clone" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">clone(\%params)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The <code>clone()</code> method creates and returns a new
<code>Template::Stash</code> object which represents a localised copy of
the parent stash. Variables can be freely updated in the cloned stash and
when <a href="#method_declone">declone()</a> is called, the original
stash is returned with all its members intact and in the same state as
they were before <code>clone()</code> was called.
</p>
<p>
For convenience, a hash of parameters may be passed into
<code>clone()</code> which is used to update any simple variable (i.e.
those that don't contain any namespace elements like <code>foo</code> and
<code>bar</code> but not <code>foo.bar</code>) variables while cloning
the stash. For adding and updating complex variables, the <a
href="#method_set">set()</a> method should be used after calling
<code>clone().</code> This will correctly resolve and/or create any
necessary namespace hashes.
</p>
<p>
A cloned stash maintains a reference to the stash that it was copied from
in its <code>_PARENT</code> member.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_declone" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">declone()</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
The <code>declone()</code> method returns the <code>_PARENT</code>
reference and can be used to restore the state of a stash as described
above.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_define_vmethod" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">define_vmethod($type, $name, $code)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
This method can be used to define new virtual methods. The first argument
should be either <code>scalar</code> or <code>item</code> to define
scalar virtual method, <code>hash</code> to define hash virtual methods,
or either <code>array</code> or <code>list</code> for list virtual
methods. The second argument should be the name of the new method. The
third argument should be a reference to a subroutine implementing the
method. The data item on which the virtual method is called is passed to
the subroutine as the first argument.
</p>
<pre>$stash->define_vmethod(
item => ucfirst => sub {
my $text = shift;
return ucfirst $text
}
);</pre>
</div>
</div>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="INTERNAL_METHODS" onclick="switch_section(this)" title="Click title to show/hide section content.">INTERNAL METHODS</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<div class="subsection">
<div class="head">
<h2 id="method_dotop" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">dotop($root, $item, \@args, $lvalue)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
This is the core <code>dot</code> operation method which evaluates
elements of variables against their root.
</p>
</div>
</div> <div class="subsection">
<div class="head">
<h2 id="method_undefined" class="method" onclick="switch_subsection(this)" title="Click title to show/hide sub-section content.">undefined($ident, $args)</h2>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
This method is called when <a href="#method_get">get()</a> encounters an
undefined value. If the
<code>STRICT|Template::Manual::Config#STRICT</code> 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.
</p>
<p>
The method can be redefined in a subclass to implement alternate handling
of undefined values.
</p>
</div>
</div>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="AUTHOR" onclick="switch_section(this)" title="Click title to show/hide section content.">AUTHOR</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
Andy Wardley <abw@wardley.org> <a
href="http://wardley.org/">http://wardley.org/</a>
</p>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="COPYRIGHT" onclick="switch_section(this)" title="Click title to show/hide section content.">COPYRIGHT</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
Copyright (C) 1996-2012 Andy Wardley. All Rights Reserved.
</p>
<p>
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
</p>
</div>
</div>
<div class="section">
<div class="head">
<h1 id="SEE_ALSO" onclick="switch_section(this)" title="Click title to show/hide section content.">SEE ALSO</h1>
<a href="#body" class="top" title="Back up to the top of the page" >Top</a>
</div>
<div class="body">
<p>
<a href="../../modules/Template.html">Template</a>, <a href="../../modules/Template/Context.html">Template::Context</a>
</p>
</div>
</div>
</div></div>
<br class="clear" />
<div class="pageinfo">
<a href="http://template-toolkit.org/docs/modules/Template/Stash.html">http://template-toolkit.org/docs/modules/Template/Stash.html</a>
</div>
</div>
<div id="footer">
<a href="http://opensource.org/" class="osi"></a>
<div class="controls">
<div class="pager">
<a href="../../modules/Template/Service.html" title="Template::Service" class="go back">Back<span class="about"><h4>Template::Service</h4></span></a>
<a href="../../modules/Template/index.html" title="Template::* Modules" class="go up">Up<span class="about"><h4>Template::* Modules</h4></span></a>
<a href="../../modules/Template/Stash/index.html" title="Template::Stash::* Modules" class="go next">Next<span class="about"><h4>Template::Stash::* Modules</h4></span></a>
</div>
</div>
<div class="copyright">
Copyright © 1996-2012 <a href="http://wardley.org/">Andy Wardley</a>. All Rights Reserved.
</div>
<div class="licence">
The <a href="http://template-toolkit.org/">Template Toolkit</a> is <a href="http://opensource.org/">Open Source</a> software.
You can redistribute and/or modify it under the terms of the <a href="http://www.opensource.org/licenses/gpl-license.php">GNU Public Licence</a>
or the <a href="http://www.opensource.org/licenses/artistic-license.php">Perl Artistic Licence</a>.
</div>
</div>
<div id="palette">
<ul>
<li class="first"><a href="#" class="blue" onclick="set_style('Clear Blue')"></a></li>
<li><a href="#" class="orange" onclick="set_style('Clear Orange')"></a></li>
<li><a href="#" class="green" onclick="set_style('Clear Green')"></a></li>
<li><a href="#" class="purple" onclick="set_style('Clear Purple')"></a></li>
<li><a href="#" class="grey" onclick="set_style('Clear Grey')"></a></li>
</ul>
</div>
</div> </body>
</html>