Template component

Introduction

This standalone template component is a part of Spoon Library.

Usage

It's pretty straightforward to start using templates. All you need to do to get started is setting up the autoloader.

// fetch and register autoloader
require_once 'Spoon/Template/Autoloader.php';
Autoloader::register();

$template = new Template(new Environment());
$template->assign('name', 'Davy Hellemans');
$template->render('index.tpl');

Environments

As you can see in the previous example, the Template class requires an 'Environment' object in the constructor. This class is used to define settings for your templates. The following things can be set in the 'environment':

• auto escape: if enabled (default) this will escape all variables in the template output.
• auto reload: if enabled (default) this will only regenerate the cached template if the source file has changed.
• cache: the location where to place the cached templates.
• charset: the charset you wish to use, default is the current directory.
• debug: if enabled this will make some extra variables available.

Variables

Template Syntax

The most basic example looks like this:

{$name}

If {$name} doesn't contain any value, null is returned. It's also possible to use a dot as a separator.

{$foo.bar}

This has several implications as to what 'bar' actually is.

• check if $foo is an array and 'bar' is an element
• check if $foo is an object and 'bar' is a public property
• check if $foo is an object and 'bar' is a public method
• check if $foo is an object and 'getBar' is a public method

If none of the checks above give any results, null is returned as with simple variables.

Modifiers

Modifiers are functions you can apply to variables. They can be chained and even contain subvariables as arguments. They're executed from left to right.

{$name|dump}
{$name|uppercase}
{$name|shuffle}
{$name|truncate(10)}
{$name|truncate($length)}

You can map your own functions/methods to modifiers. The only requirement is that they need to be a valid callback. All the examples below are ok and should work just fine.

$environment = new Environment();
$environment->mapModifier('strlen', 'strlen');
$environment->mapModifier('date', array('MyClass', 'date'));
$environment->mapModifier('date', array(new MyClass(), 'date'));
$environment->mapModifier('test', function($value){ return test($value) });

Arguments

Arguments can be either strings, integers or subvariables.

{$name|substring(0, 5}}
{$name|substring(0, $length)}
{$name|sprintf('foo')}

As you can see. There's no need to encapsulate the subvariable with brackets.

Subvariables

As seen in the example above, subvariables can be used in a nifty way. However there are some restrictions. At this moment it's not possible to apply modifiers to subvariables. I'm planning to add this in the future.

The same rules apply as with regular variables concerning the chaining of subvariables.

{$name|sprintf($foo.bar.baz)}

Comments

You can use single or multiline comments. The template code between the tags will not be rendered.

{* single line comment *}
{*
	multiline comment
*}

Including templates

The 'include' tag is used to include other templates. The path is always based on the location of the template wherin the include tag resides. Following examples are ok.

{% include 'template.tpl' %}
{% include $template %}
{% include $path . '/template.tpl' %}
{% include '/home/spoon/' . $directory . '/template.tpl' %}

Control structures

If, elseif, else

There are quite a few possibilities. I've listed some of the most commonly used ones and if you use your imagination you can come up with a lot more examples.

{% if $name %} ... {% endif %}

{% if $name == 'Davy' %} ... {% endif %}

{% if $name != 'Davy' and $name != 'Erik' %} ... {% endif %}

As you can see subvariables can be used within if constructions. The same rules as with PHP are applied to these constructions. You can use and combine the following expressions:

or, and, ==, !=, <, >, >=, <=, +, -, *, /, %

You can also use elseif and else constructions.

{% if $name == 'Davy' %}
	...
{% else %}
	...
{% endif %}

Or you could just use one (ore more) elseif statement(s) which could look like this:

{% if $name == 'Davy' %}
	...
{% elseif $name == 'Dave' %}
	...
{% elseif $name == 'Jelmer' %}
	...
{% else %}
	...
{% endif %}

For loop

The for loop is used to loop over arrays or objects. The best way to explain is by showing an example.

{% for $dog in $animals %}
	{$dog}
{% endfor %}

There are some custom loop specific variables you can access while doing loops.

• loop.count, number of items in the loop
• loop.first
• loop.last,
• loop.index, counter starting from 1.
• loop.key
• loop._parent, the parent context of this loop.

These extra variables might come in handy for template designers. A brief example below.

{% if $users %}
	<ul>
		{% for $user in $users %}
			<li{% if $loop.first %} class="first"{% endif %}>
				{$loop.index} - {$user}
			</li>
		{% endfor %}
	</ul>
{% endif %}

Debug

You can see which variables are available in the current template by using the debug tag. This will use var_dump to show the contents of the assigned template variables.

{% debug %}