Templating System

bpat1434

Hey guys/gals...
I've looked over phpBB's templating system, and still tough to wrap my head around it. I would love for some help (if you can). Basically, I want to make my next site work like so:

1.) PHP grabs the template file that is needed to display the requested information
2.) PHP looks for tags of the type "" and ""
3.) All HTML/template code in between there will be parsed according to the "some_unknown_function"
4.) PHP searches for actual tags & replaces them (<-- That one I know how to do)

I can do basically most of it, except the whole looping or executing code issue. Here's where your help will come in. NOTE: I am going to post this over at phpBB forums, but figure I might get a more pleasant response here. How would one go about implementing something like this? Like if I wanted one section to be repeated over and over as part of the query, but yet keep the PHP separate from the HTML/Template?

Here's a small example of what I'd want:

<html>
<!-- Some other code that is currently removed for space -->
<body>
<div id="main">
  <div id="content">
    <!-- BEGIN mySQL_Loop -->
    <div class="item">
      <div class="title">{itemTitle}</div>
      <p class="cont">{itemContent}</div>
    </div>
    <!-- END mySQL_Loop -->
  </div>
</div>
</body>
</html>

So how would one go about doing that? I've opened up the "template.php" file in the phpBB distribution, but get lost when they start talking about blocks, and levels. Can anyone shed light on this? Or perhaps point me in the direction of a tutorial that actually explains how to create this type of a templating system?

Thanks for any help you can offer.

~Brett

thorpe

everyone is going to have different opinions on this, and mine is, why bother. what is the difference between what you posted, and something like this? besides of course the fact that mine will run faster as it doesn't need to parse a template.

<?php
  include("items.class.php");
  $items = new items();
?>
<html>
<!-- Some other code that is currently removed for space -->
<body>
<div id="main">
  <div id="content">
    <?php foreach($items as $item) { ?>
    <div class="item">
      <div class="title"><?php echo $item[0]['itemTitle']; ?></div>
      <p class="cont"><?php echo $item[1]['itemContent']; ?></div>
    </div>
    <?php } ?>
  </div>
</div>
</body>
</html>

my point being, somewhere along the line, if you want conditionals and loops your going to need to store logic in your template anyway so why not just use php? if you keep most of your business in classes, or even just functions, its allot more efficient / easier to just use php.

ive tried a few template engines, even rolled my own (very slow), but now, i just dont see the point anymore.

bpat1434

hmm... okay. I see what you're saying.... thanks.

I would like to hear the other opinions though...

~Brett

Weedpacket

Here's an interesting perspective on templating engines and which bits ought to be where. The upshot is that you still use PHP in the template; it's just that you separate presentation-level code (that stays in the template) from the rest (that is separate and just sends data to the presentation level). Like separating style and content in pages - distinguishing between "what is shown" from "how it's shown".

cmircea

Hey, Here is an article describing how template systems work:
http://www.askbee.net/articles/php/Template_System/create_your_own_template_system.html

vaaaska

I used to wonder the same thing bpat. Why use some new markup when PHP is just fine. That is until I had a situation where one user was qualified to use PHP, another was not but both needed access to a core set of variables (page title, etc). And so, with a permissions system in place I created something that allowed for all of the above.

Kind of a pain, but the more users you have the more everything makes a kind of sense.

I second the article Weedpacket linked...that thing has it's own kind of legendary status.

Weedpacket

vaaaska wrote:
I second the article Weedpacket linked...that thing has it's own kind of legendary status.

It certainly made a lot of sense to me when I first came across it (I forget just when). To use your situation where you had two people, one who knew PHP and one who didn't, it seems to make a lot of sense to me to have the second person learn a reduced subset of PHP syntax of the "stick the content of this variable here" variety than to have both people learn a whole new ad hoc scripting language (which is pretty much what you get with Smarty).

It would benefit both of them, because the first one doesn't have to learn the new language (and implement it as well!), and the basic knowledge gained by the second person could be used as a foundation that can develop into more sophisticated constructs without requiring rewriting of the template engine.

Of course, the more sophisticated the presentation scripting gets, the more risk there is of having it do what should be done in the business logic. The rule-of-thumb I use is "does this code depend on how the front end is implemented?" The business logic shouldn't have to care if the UI is written in HTML, XUL, Flash, or whatever.

jazz_snob

thorpe wrote:
everyone is going to have different opinions on this, and mine is, why bother

I'll second that opinion.

I recently did my first project using templates ( xtemplates to be exact) ...every change I had to make in the PHP code I had to make 2x (once in the logic, once in the template to add the new form field ).

As we all know, client requirements magically grow and expand once the project is completed to their original specs and they finally realize "oh yeah, we need to have these other 5 features too!" 😉 I'm gonna stick w/ 'include' as my anti-templating engine.

harmor

I use the "eval" function with my html in a database.

I heard that "eval" is insecure but I do not see it.
Even vBulletin uses eval.

Doto

cmircea wrote:
Hey, Here is an article describing how template systems work:
http://www.askbee.net/articles/php/Template_System/create_your_own_template_system.html

nice tutorial 🆒

thank you bro...