Enabling the use of looping (for in ..) into Template.php

[thiagolima-bm]

This update enable the use of loop into template files, allowing the user iterate through collections

Why do I think that this change is important?

This way would be more easy to create dynamic feed/exportation files as: xml, csv and so on.

Manual testing scenarios

$_things = new \Magento\Framework\Data\Collection($this->entityFactory);
$thing_1 = new \Magento\Framework\DataObject();
$thing_1->setName('Richard');
$thing_1->setAge(24);

$thing_2 = new \Magento\Framework\DataObject();
$thing_2->setName('Jane');
$thing_2->setAge(12);

$thing_3 = new \Magento\Framework\DataObject();
$thing_3->setName('Spot');
$thing_3->setLastName('The Dog');
$thing_3->setAge(7);

$_things->addItem($thing_1);
$_things->addItem($thing_2);
$_things->addItem($thing_3);

// you may also use arrays
/*
$_things = [
['name' => 'Richard', 'age' => 24],
['name' => 'Jane', 'age' => 12],
['name' => 'Spot', 'age' => 7],
];
*/

$order = $this->orderRepository->get(1);

$template = new \Magento\Framework\Filter\Template(new \Magento\Framework\Stdlib\StringUtils);

$value = "
    Increment ID: {{var order.increment_id}} <br>
    
    <ul>
        {{loop order.all_visible_items}}
            <li>
                sku: {{var item.sku}}<br>
                name: {{var item.name}}<br>
                price: {{var item.price}}<br>
                quantity: {{var item.ordered_qty}}<br>
            </li>
        {{/loop}}               
    </ul>
    
    
    Customer Email: {{var order.customer_email}}
    
    <ul>
        {{loop things}}
            <li>{{var item.indexCount}} name: {{var item.name}}, lastname: {{var item.lastname}}, age: {{var item.age}}</li>
        {{/loop}}
    </ul>"
;

$template->setVariables(array('order' => $order, 'things' => $_things));

echo $template->filter($value);

Output:

<ul>
    
        <li>
            sku: WS03-XS-Red<br>
            name: Iris Workout Top-XS-Red<br>
            price: 0.0000<br>
            quantity: <br>
        </li>
                   
</ul>


Customer Email: [email protected]

<ul>
    
        <li>1 name: Richard, lastname: , age: 24</li>
        
            <li>2 name: Jane, lastname: , age: 12</li>
        
            <li>3 name: Spot, lastname: , age: 7</li>
    
</ul>

[bap14]

What would the output of this look like? Is it possible to utilize an inline-template call within the loop to customize the display of items?

[adragus-inviqa]

You should allow more than arrays and object collections in here.
You should use is_array($data) || ($data instanceof Traversable).

[thiagolima-bm]

Applied :)

[adragus-inviqa]

Ah, yes - Varien_Data and Varien_Data_Collection. Good times, good times.

[thiagolima-bm]

@bap14 Lets suppose that you have the following template:
`

Increment ID: {{var order.increment_id}}

    <ul>
        {{loop order.all_visible_items}}
            <li>
                sku: {{var item.sku}}<br>
                name: {{var item.name}}<br>
                price: {{var item.price}}<br>
                quantity: {{var item.ordered_qty}}<br>
            </li>
        {{/loop}}               
    </ul>
    
    
    Customer Email: {{var order.customer_email}}
    
    <ul>
        {{loop things.collection}}
            <li>name: {{var item.name}}, lastname: {{var item.lastname}}, age: {{var item.age}}</li>
        {{/loop}}
    </ul>`

The output would be:
` Increment ID: 000000001

    <ul>
        
            <li>
                sku: WS03-XS-Red<br>
                name: Iris Workout Top-XS-Red<br>
                price: 0.0000<br>
                quantity: <br>
            </li>
                       
    </ul>
    
    
    Customer Email: [email protected]
    
    <ul>
        
            <li>name: Richard, lastname: , age: 24</li>
        
            <li>name: Jane, lastname: , age: 12</li>
        
            <li>name: Spot, lastname: , age: 7</li>
        
    </ul>

`

[thiagolima-bm]

@adragus-inviqa I have fixed that. Sorry! M1 is still running in my brain hehe

[orlangur]

Hi guys, I see a lot of thumbs up here which means Community is really in need of such functionality, but...

Do you really think it's a good idea to expand some custom templating language? For example, Twig is a pretty mature technology, has pretty similar syntax and loop out-of-the-box.

There is even some attempt https://github.com/kalenjordan/magento-twigmail to introduce Twig support in email templates for Magento 1 :)

[thiagolima-bm]

@orlangur I would say so but, I do know how much effort will be needed. At least my PR does not affect the actual M2 behaviour. :)

[ishakhsuvarov]

Hi @thiagolima-bm
I generally like the idea of the changes proposed, however I would encourage you to look into some additional features which may be added to theloop. Current implementation may solve just a single problem which is iteration of the specified collection.
Real life usage may require more versatility to the solution such as access to the information on array keys. Link provided above has some information on that.
If you would like to continue work on this PR we could come up with the minimum list of capabilities for such feature.

Thanks

[thiagolima-bm]

@ishakhsuvarov Hey, I would like to continue. You can come up with the list ASAP

[okorshenko]

Hi @thiagolima-bm do you have any progress on that or should we close this PR?

[thiagolima-bm]

@okorshenko Yes. The use of arrays is available too.

[thiagolima-bm]

@ishakhsuvarov Updated.

[orlangur]

@thiagolima-bm, thanks for considering Twig 👍 I don't think it would require too much efforts but will not insist until I have some proof-of-concept in my hand :)

Sorry for not answering for a long time, I had something to say but somehow lost this thread and then forgot.

What do you think about making your implementation more Twig-like instead of custom syntax?

So, instead of

{{loop order.all_visible_items}}
    <li>
        row number: {{var item.itemCount}}<br>
        sku: {{var item.sku}}<br>
        name: {{var item.name}}<br>
        price: {{var item.price}}<br>
        quantity: {{var item.ordered_qty}}<br>
    </li>
{{/loop}}        

I think it would be better to partially implement capabilities of https://twig.sensiolabs.org/doc/2.x/tags/for.html

{{for item in order.all_visible_items}}
    <li>
        row number: {{var loop.index}}<br>
        sku: {{var item.sku}}<br>
        name: {{var item.name}}<br>
        price: {{var item.price}}<br>
        quantity: {{var item.ordered_qty}}<br>
    </li>
{{/for}}

I think it's enough to implement subset of Twig features consisting of {{for, loop.index, loop.first, loop.last and loop.length. In such case we will make learning curve steeper for many developers and will avoid headache if we ever replace custom email templates with Twig or similar engine.

Also, would be really nice to place sample syntax in filterFor method PHPDoc.

Please share your thoughts.

[thiagolima-bm]

@ishakhsuvarov @orlangur

`

Increment ID: {{var order.increment_id}}

    <ul>
        {{for item in order.all_visible_items}}
            <li>
                index: {{var loop.index}}
                sku: {{var item.sku}}
                name: {{var item.name}}
                price: {{var item.price}}
                quantity: {{var item.ordered_qty}}
            </li>
        {{/for}}               
    </ul>
    
    Customer Email: {{var order.customer_email}}
    
    <ul>
        {{for thing in things}}
            <li>{{var loop.index}} name: {{var thing.name}}, lastname: {{var thing.lastname}}, age: {{var thing.age}}</li>
        {{/for}}
    </ul>`

The output would be:
`

Increment ID: 000000001

    <ul>
        
            <li>
                index: 1
                sku: WS03-XS-Red
                name: Iris Workout Top-XS-Red
                price: 0.0000
                quantity: 
            </li>
                       
    </ul>
    
    Customer Email: [email protected]
    
    <ul>
        
            <li>1 name: Richard, lastname: , age: 24</li>
        
            <li>2 name: Jane, lastname: , age: 12</li>
        
            <li>3 name: Spot, lastname: , age: 7</li>
        
    </ul>

`

[thiagolima-bm]

@ishakhsuvarov @orlangur @okorshenko The changes were made.

[thiagolima-bm]

@orlangur I do not know what is happening, but when I run these tests in my machice, everything works fine.

Integration tests works fine.
But, somehow, when running unit tests
Fatal error: Cannot declare class Magento\Framework\Filter\Test\Unit\TemplateTest, because the name is already in use in /home/travis/build/magento/magento2/vendor/magento/framework/Filter/Test/Unit/TemplateTest.php on line 373

[orlangur]

vendor/magento/framework/Filter/Test/Unit/TemplateTest.php you should not commit anything into vendor folder, test is placed in https://github.com/magento/magento2/blob/develop/lib/internal/Magento/Framework/Filter/Test/Unit/TemplateTest.php

[magento-cicd2]

All committers have signed the CLA.

[thiagolima-bm]

Thanks, @orlangur! All set.

[okorshenko]

Hi @thiagolima-bm could you please look at failed static tests?

[okorshenko]

Fixed on our side

[thiagolima-bm]

Ok!

[thiagolima-bm]

@okorshenko somehow, my contributor label is missing :(

[orlangur]

Hi @thiagolima-bm, as we already discussed in scope of another PR, this is not something Magento can handle on its side.

Please make sure all emails used for commits: https://github.com/magento/magento2/pull/9401/commits are associated with your current account.