data_sources.md

How {{macro}} template gets data for displaying?

{{macro}} usually works with plain PHP scalar values or arrays. However, if you want your objects to be fully supported in {{macro}} as well, make sure that your object supports ArrayAccess (in case of accessing attributes using dotted syntax) or Iterator (in case of iteration).

There are two common ways to make some data appear inside a template:

• push — data is pushed into template externally with some simple interface like set($var, $name) or assign($var, $name).
• pull — template code fetches required data internally by using helpers or callbacks.

{{macro}} supports both of these approaches.

Push approach

lmbMacroTemplate has set($variable_name, $value) method that sets global variable $variable_name in the template. This variable will be available in template as {$#variable_name} or {$this→variable_name} expressions.

For example:

$macro = new lmbMacroTemplate('page.phtml');
$macro->set('title', 'Hello');

To render 'title' in {{macro}} template we can use the following expression:

{$#title}

There is also lmbMacroTemplate :: setVars($associative_array) that is equal to several set() method calls for every element of $associative_array. Note: setVars() removes previously assigned variables.

Pull approach

You can also use arbitrary PHP blocks right in {{macro}} templates to fetch data, e.g.:

<? $products = lmbActiveRecord :: find('Product'); ?>
{{list using='$products' as="$product"}}
<ul>
  {{list:item}}
    <li>{$product.title}</li>
  {{list:item}}
</ul>
{{/list}}

Data from lmbController

If you create an application based on WEB_APP package of Limb3, you may be interested to know that template can access all attributes of the currently executed controller(just like you called lmbMacroTemplate :: set() for every controller attribute).

For example:

class MyController extends lmbController
{
  function doDisplay()
  {
    $this->title = 'Hello';
  }
}

In the corresponding {{macro}} template $title attribute will be available as:

{$#title}

Contexts in {{macro}}

{{macro}} has only 2 contexts or data scopes:

• global — scope of the generated PHP class of template
• local — scope of one method of this class.

Rendering always starts with render() method of the generated PHP class. Some tags like include or apply generate their code into separate methods and thus create other local scopes. {{include}} and {{apply}} allow to pass any variables into their local scopes with any number of extra attributes (see descriptions of these tags).

See also output expressions.