Module: TemplateEngineFactory

[Wanze]

TemplateEngineFactory

The main idea of this module is to support the developer separating logic from markup.

This is achieved by turning ProcessWire templates into controllers which interact over a new API variable to template engines like Smarty or Twig. The TemplateEngineFactory ships with a default engine "ProcessWire" that uses the internal TemplateFile class to render the templates (some of you may already be familiar with this concept). However, the module is constructed in a way that any template engine can be used, implemented as separate modules.

Please check out the readme on GitHub for more details how it works: https://github.com/wanze/TemplateEngineFactory

... or in the modules directory: http://modules.processwire.com/modules/template-engine-factory/

• Implementation of Smarty: https://github.com/wanze/TemplateEngineSmarty
• Implementation of Twig: https://github.com/wanze/TemplateEngineTwig
• Implementation of Jade (by dreerr, thanks!): https://github.com/dreerr/TemplateEngineJade

How does it work?

A controller (aka ProcessWire template) can have an associated template file which contains the markup to render. The folder where those templates are stored is configurable for each installed engine. If the Factory finds a template file with the same name as the controller, an instance to access the template is provided with a new API variable (called "view" by default). Over this API variable, you can set the dynamic variables that should be rendered. Hopefully the following example makes things clearer:

// In controller file: /site/templates/home.php

if ($input->post->form) {
  // Do some processing, send mail, save data...
  $session->redirect('./');
}
// Pass variable to the template
$view->set('foo', 'bar');
$view->set('show_nav', true);
$view->set('nav_pages', $pages->get('/')->children());

As you can see, there is no markup echoed out. The corresponding template file is responsible for this task:

// In template file: /site/templates/view/home.php

<h1><?= $page->title ?></h1>
<p>Foo: <?= $foo ?></p>

<?php if ($show_nav): ?>
  <ul>
  <?php foreach ($nav_pages as $p): ?>
    <li><a href="<?= $p->url ?>"><?= $p->title ?></a></li>
  <?php endforeach; ?>
  </ul>
<?php endif; ?>

In the example above, "ProcessWire" is used as engine. If Smarty is the active template engine, the corresponding template file could look like this:

// In template file: /site/templates/smarty/home.tpl

<h1>{$page->title}</h1>
<p>Foo: {$foo}</p>

{if $show_nav}
  <ul>
  {foreach $nav_pages as $p}
    <li><a href="{$p->url}">{$p->title}</a></li>
  {/foreach}
  </ul>
{/if}

Note that the API variable acts as a gateway which connects you to the activated template engine. We can switch the engine behind without changing the controller logic! (I know that this is probably not a very common need, but it's a cool thing anyway )

For further information, please check out the readmes on GitHub. Please ask questions if anything makes no sense - sometimes it's hard to get my explanations

Cheers

[marcus]

Oh, this is perfect timing! Taking this for a test drive as soon as possible. Lately, I was aiming at the exact same thing. But this looks perfectly done with the possibility to plug in your favorite template engine! Thanks, Wanze!

[felix]

You may want to have a look at TemplateDataProviders which is pretty similar to your module

[pwFoo]

Used templateFile class before to build a site. You module should make it even easier...

Is it planned to add a template cache (to cache the "views") in the future? 

Don't know how much time caching would be save at a small / medium site...

I'll try your module soon to build a pocketGrid base layout also with sub templates 

[pwFoo]

Hi Wanze,

after a short test...

1) My setup seems not supported

// init html basic template / layout
$tpl = new TemplateFile();
$tpl->filename = $config->paths->templates.'views/html.tpl.php';

// here handle page controller / view stuff
[...]
$pagePart = $pageTpl->render();

$tpl->set('subtpl', $pagePart);

echo $tpl->render();

Because you render and output $pagePart module controlled/ inside I can't use it as sub template

Could you make this use possible with TemplateEngineFactory module?

2) Get a 500 error if use chunks / sub templates (for example my html layout view...)

$factory = $modules->get('TemplateEngineFactory');

$chunk = $factory->load('views/html.php');
$chunk->set('test', 'TEST');
echo $chunk->render();

 

At the moment html.php is simple:

<h1><?php echo $page->title; ?></h1>
<p><?php echo $test; ?></p>

Any idea?

Maybe you can make my setup working with your module?

[Wanze]

Hi pwFoo,

Thanks for your interest

Now you're mixing things bit up that's why it does not work. I assume that you've chosen "ProcessWire" as TemplateEngine?

Then the TemplateFile class is also used to render your templates.

1) My setup seems not supported
Because you render and output $pagePart module controlled/ inside I can't use it as sub template 
Could you make this use possible with TemplateEngineFactory module?

 

If you are in your /templates/basic_page.php controller, then the factory has loaded for you already the corresponding template file ine /templates/views/basic_page.php.

Your code loading the html.tpl.php file and echo out it's markup will not have any effect, because the factory will use the /templates/views/basic_page.php file for the output. You'd want to pass the variables to that template file with $view->set();

 

2) Get a 500 error if use chunks / sub templates (for example my html layout view...)

 

In the module's setting of TemplateEngineProcesswire you define where your template files are stored.

When loading a file with the factory, it looks inside that folder. So I guess maybe it wil work so:

// Template files are in /site/templates/views/

$chunk = $factory->load('html.php'); // File is in /site/templates/views/html.php
$chunk2 = $factory->load('chunks/html.php'); // File is in /site/templates/views/chunks/html.php

Now again, if you are in a controller where a corresponding template file exists, echo out will have no effect. You'd need to pass 

the markup to your template:

// In /site/templates/basic_page.php

$view->set('chunk', $chunk->render());

// In /site/templates/views/basic_page.php

<p><?= $chunk ?></p>

Hope I could make things clearer?

Cheers

[pwFoo]

Hi wanze, 

I don't think I'll use the wrong path to the template / chunk, but double check

Don't know my planned setup is clear so far...

I would NOT output html.php inside basic_page view..., but try to output basic_page view inside html.php view! 

Won't work, I found your hook into render at source code...

html.php

<html>
  <head>
[...]
  </head>
  <body>
    <p><?php echo $basic_page; ?></p>
  </body>
</html>

Hope the simplified example should show what I need

$basic_page is the part of current page done by your module.

Maybe I could cutting my html.php to something like html_start.php and html_end.php to get it around basic_page...

Maybe views should be not .php because it's confusing to have TWO identical files open at editor / IDE.

I'll like to use .tpl or .tpl.php to differ controller and view / template.

[Wanze]

I think I understand, this is a little different need. You'd have to tell the factory that your main template file is now html.php.

Could you try something like this (not tested!):

// In basic_page.php controller

$factory = $modules->get('TemplateEngineFactory');
$basic_page = $view; // Save basic_page template which is currently behind the $view API variable
$main = $factory->load('html.php'); // Load the main markup
wire()->set('view', $main); // Set the context of wire view variable to be the main template
$view = wire('view'); // Reassign to locally scoped $view variable - not sure if this is necessary, but I think so...
$view->set('basic_page', $basic_page->render()); // Pass output of basic_page to main template

If this should work, you could enable $config->prependTemplateFile an put the code in your prepended controller file, e.g. _init.php.

Maybe views should be not .php because it's confusing to have TWO identical files open at editor / IDE.

I'll like to use .tpl or .tpl.php to differ controller and view / template.

I'll add support for that so that you can define the suffix. Actually this is supported by the Smarty and Twig additions, don't know why I did not add this for the ProcessWire engine

[pwFoo]

So I'll test it soon. Thanks for help

Maybe a option for module configuration?

Define a global view to be used as main view?

I'll add support for that so that you can define the suffix. Actually this is supported by the Smarty and Twig additions, don't know why I did not add this for the ProcessWire engine 

Great! 

[Wanze]

Maybe a option for module configuration?

Define a global view to be used as main view?

I updated the module to version 1.0.1.

All engines now have a setting Global template file where you can enter the filename of a template file that is used as "main template" behind the API variable.

This is useful if you have a main template that contains all the markup and you need to fill certain variables per controller.

Note that Smarty and Twig already support this feature with template inheritance.

Also the TemplateEngineProcesswire module now supports custom suffixes for the template files. Change this setting if you'd like to name the templates different than the controller, e.g "home.tpl.php".

Cheers

[pwFoo]

Hi Wanze,

global template works with following example.

$factory = $modules->get('TemplateEngineFactory');

$subtpl = $factory->load('basic-page'); // current page template / view basic-page.tpl
$subtpl->set('subtplvar', $page->body); 

// global template / view
$view->set('title', $page->title);
$view->set('subtpl', $subtpl->render()); // render sub template to global template variable

I think that's how it should be used?

How did it work with smarty / twig? Was it a include inside a template to load a sub template?

If I'm right template engine can't simply switched between Processwire and Smarty/Twig because template variables seems to be handled different?

PW -> load sub template & fill it like your chunk example

Twig/ Smarty -> include sub templates and fill all the template and sub template variables via api variable?

Don't know I'm right or if it's possible. But would be nice to get it filled the same way 

At the moment I'm only working with pw template class, but maybe I'll could be switch it later... So it would be a great feature have template parser independent code

[Wanze]

I think that's how it should be used?

Yep, looks fine to me!

Another approach could be to use ProcessWire's prepend template file option. This way, you can populate the variables in your global template and overwrite them in the controllers, if needed.

Let's assume that we have a variable 'content' and 'sidebar' in our global template.

// Populate default values in prepended template file, e.g. _init.php
$view->set('content', $page->body);
$sidebar = $factory->load('chunks/sidebar');
$sidebar->set('a_variable', 'a_value');
$view->set('sidebar', $sidebar->render());

Now in the home controller, the content variable is more complex, we overwrite it:

// In home.php the content variable is pouplatet differently
$home = $factory->load('home');
$home->set('images', $pages->find('template=gallery,sort=-created,limit=3');
$view->set('content', $home->render());

How did it work with smarty / twig? Was it a include inside a template to load a sub template?

If I'm right template engine can't simply switched between Processwire and Smarty/Twig because template variables seems to be handled different?

It works the same, switching the template engine is possible as long as you use the same template filenames (the ending/suffix can be different) and identical variable names. This is possible because behind the API variable is not directly the engine like Smarty or Twig but sort of a 'gateway class' that talks to those engines. Notice that in my examples above I loaded the template files without the suffix, just the filename. Depending on the active filename, the correct template is loaded.

As an example, you could (though this is probably a very rare need) store your templates like this:

• For the ProcessWire engine: In folder /site/templates/views/
• For the Smarty engine: In folder /site/templates/smarty/

Now if ProcessWire is the active engine and you load the template 'home', a file in /site/templates/views/home.tpl.php gets loaded (whatever you've configured as template file suffix). If Smarty is active, the file /site/templates/smarty/home.tpl is loaded.

Don't know I'm right or if it's possible. But would be nice to get it filled the same way  

At the moment I'm only working with pw template class, but maybe I'll could be switch it later... So it would be a great feature have template parser independent code

It works as long as you have your template filenames and variable names consistent

However, when switching to a template engine like Smarty or Twig you should check out template inheritance. In my opinion, this is the most powerful feature and one of the main reasons to use a template engine. For smarty, I've written a little section how this could work: 

https://github.com/wanze/TemplateEngineSmarty#best-practices

Cheers

[clsource]

Really awesome module, great work!

I just have one question, 

If in one controller I need to render two different templates

how can it be done?

Example home controller

and two themes, one for night other for day.

So the controller check the time and load the corresponding view.

[Wanze]

Really awesome module, great work!

I just have one question, 

If in one controller I need to render two different templates

how can it be done?

Example home controller

and two themes, one for night other for day.

So the controller check the time and load the corresponding view.

Thanks!

If the HTML markup is the same, maybe you could solve it with loading different CSS files. If markup is different, you'd need to dynamically set the template that is behind the API variable ($view or your custom name).

Something like this, not tested:

$theme_template = isDay() ? 'day' : 'night';
$theme = $factory->load($theme_template); // Load the correct theme
wire()->set('view', $theme); // Set the context of view variable to be the correct theme template
$view = wire('view'); // Reassign to locally scoped $view variable - not sure if this is necessary, but could be

This must happen before you pass any variables to $view. If you need this check on the whole site, you could also use ProcessWire's prependTemplateFile option and put this code in your prepended template file (controller).

[peterfoeng]

Wanze, this is a very nice module I am playing around with it now

[Wanze]

Wanze, this is a very nice module I am playing around with it now

Thanks

Today I pushed a little update (v.1.0.2) with some improvments. If you update to this version and already installed/used Smarty or Twig, make sure to update those modules as well.

What's new?

When loading a template file with the factory, you can optionally tell the module to use the given file behind the API variable:

$factory = $modules->get('TemplateEngineFactory');
$view = $factory->load('pw_rocks', true);

Setting the second parameter to true, the template file 'pw_rocks' is now used as active template behind the API variable.

In the example above, the template file is also assigned to '$view' which reflects this change also to the $view variable which is locally scoped in controllers. Whatever template is set behind the $view variable is used by the module when rendering the output of a page.

[peterfoeng]

Hi Wanze,

Any direction how to configure this with $config->ajax?

<?php
//we use the page title as template
$template = $sanitizer->name($page->title);

/* render load body */
$body = $factory->load('custom-templates/' . $template. '.php');

if ($config->ajax) {

$view = $factory->load('custom-templates/_Ajax.php', true);
return;
}

/* render custom-templates */
$view->set('Body', $body->render());

I tried the code above but I dont get the desired result. I am setting the global template with my setup. Need a bit of help Thanks

[Wanze]

Hi peterfoeng,

What is the content of your _Ajax.php file?

Does it work if you do echo ou the template and the exit if you do not have to process any additional logic?

if ($config->ajax) {
  $view = $factory->load('custom-templates/_Ajax.php', true);
  echo $view->render();
  exit;
}

Cheers

[peterfoeng]

Hi Wanze,

I figured it out, this is a silly mistake of not supplying the correct path LOL!

<?php
//we use the page title as template
$template = $sanitizer->name($page->title);

/* render load body */
$body = $factory->load('custom-templates/' . $template. '.php');

if ($config->ajax) {
  $view = $factory->load('_Ajax.php', true);
}

/* render custom-templates */
$view->set('Body', $body->render());

So, I am rendering the body with the global template option and if there is an ajax request, the global template is overridden with ajax.php or empty template using $factory->load()

Silly mistakes!

[Frank Vèssia]

hi Wanze, this system is awesome but I'm getting some issues working with the "Global template file" option, probably i didn't get the right purpose of this.

my setup is:
"templates/views/" for the path
"tpl" for the extensions
this works good as long as i use files like home.php + home.tpl
but when i set
"main" for the Global template file (or should write main.php??)
i get just blank pages.
Can you please provide an example of the correct use of this option and file structure ?
 

[Wanze]

Hi Sevarf2,

Sorry for my late response...!

"main" for the Global template file (or should write main.php??)

Just "main" or "main.tpl" if you've set "tpl" as the extension.

i get just blank pages.
Can you please provide an example of the correct use of this option and file structure ?

What is the content of your main.tpl? You should see this content rendered by the selected engine.

This option is useful if your controllers (aka Pw-Templates) all render the same markup. With this option, you'd define this markup in your "main.tpl" file, and home.php would render it. If you don't use the global template file, home.php would render "home.tpl".

Does it make sense?

Cheers

[Frank Vèssia]

Thanks now it's clear.

[Stikki]

This looks very nice module Wanze, thanks.

One thing i don't understand.

Why people hook into Page::render instead of TemplateFile::render, which is actual ultimate output buffer for templates.

Forked your module and trying to figure out this and that, i like it mostly, just few things i wanted to test out.

Sorry if this post is on wrong forum section, feel free to move it to proper place.

[Wanze]

Hi Stikki,

Thanks!

Please report any issues or new features you'd like to see here!

Why people hook into Page::render instead of TemplateFile::render, which is actual ultimate output buffer for templates.

Never thought about that, have you tried it?

[Sergio]

This option is useful if your controllers (aka Pw-Templates) all render the same markup. With this option, you'd define this markup in your "main.tpl" file, and home.php would render it. If you don't use the global template file, home.php would render "home.tpl".

Hi Wanze!

I'm having trouble understanding the file structure yet.  

What happens with PW's _main.php and _init.php?

Where the views get the project's css/js/etc.?

What am I missing?