What are your templating strategies?

Question

I try to develop my own little framework. For this, I'd like to read up some templating techniques. I know that templating is a really complex topic, but knowing some strategies could help find the right one.

Please, if you mention one, don't just write "smarty" for example. Write a little about the concept behind it.

Let me start with an idea: To make things simple, my template files are just PHP files that contain HTML. Templates may include other templates. The data is inserted into the templates through a $data variable, which is an associative array containing all the data for the template.

So, at the first stage a controller performs some action and builds up that $data array. Next, the appropriate template will be included.

Problems: A Template might have to include not only templates, but also controllers. i.e. displaying a breadcrumb or menu (with fairly complex logic behind, far too complex to be handled in a template).

Answer 1

This is exactly how I do it, instead of calling a Controller in the View (WHAT?!?) I just compute all the necessary data for the view in the Controller that calls the View in the first place.

A View should never call a Controller / Model! BUT, if you must you can do something like this:

function Controller($pathToControler) // instantiates and returns the Controller
function Model($pathToModel) // instantiates and returns the Model

That way, inside your view you can do something like this:

$this->Controller('path/to/blog/tags.php')->List();

Again, you shouldn't use this pattern, I'm just giving you solutions, not encouraging them.

Similarly, you can also call another view from within a view, like this:

$this->View('path/to/views/header.php', array('title' => 'Hello World!'));

Answer 2

I really enjoyed zend-framework approach to this, and have used it myself in our framework. You will have a view class with will have things like:

$view = new View();
$view->setTemplatesPath('.....');
$view->assign('name','value');
$view->render('index');

the render method will take all the variables stored and make them properties and include the template based on the Path set, so in your templates you will have:

<?php echo $this->foo; ?>
....
<?php echo $this->load('header'); // this includes another template ?>

Answer 3

Have a look at the section Web Presentation Patterns, especially Template View, Transform View, Two-Step View. For stuff like rendering breadcrumbs or pagination, you can utilize a View Helper pattern.

Answer 4

My strategy is as follows:

1. Try and use the minimum of PHP in the template and if possible down to none.
2. I have created classes for various components commonly found in web pages, one of them is tpanel which I am using to demonstrate the concept below
3. tpanel for example would handle all the logic to create a menu, parses a small template for 'navigation_menu' and sends the result for final inclusion to overall template.

Effectively I am creating 'blocks', very similar to what Drupal does - if you are familiar with it.

        $this->load->library('tpanel');
        $s=$this->tpanel->get('date',$data);
        $s.=$this->tpanel->get('navigation_menu',$data);
        $s.=$this->tpanel->get('ajax_menu',$data);
        $s.=$this->tpanel->get('spacer',$data);
        $data['title']='List of Databases';
        $post=$this->uri->segment(5);
        $blog=(file_get_contents('../'.$dir.'/'.$post.'.dat'));
        $s.=markdown($blog);
        $data['content']=$s;
        $view='/admin/admin_simple_view';

The system is much more flexible that what I have shown above. For example the tpanel->get('ajax_menu, $data) also handles the script settings using jQuery.

I have been also looking at Django lately and they have some very good ideas on templating. It might be worth getting a look, even if you are not a Python programmer, especially how they handle inheritance.

Answer 5

This is not directly related to your question, but have you considered client side templating? John Resig has a nice micro-template in Javascript that will work with web services and other Ajax techniques. It's quite simple to do a get or post for the template, and then do another get/post for your data. It's quite handy.