Adding PHP logic withing .twig file - php

I am not very familiar with TWIG templates and I need to add a bit of logic to a template file based on the URL. I know how to do it in PHP, but am sort of lost here.
I can get the full URL using {{ app.request.uri }} but what I am really trying to do is something like this:
$uri = $_SERVER['REQUEST_URI'];
if ($uri == "/page1" ||strpos($uri, "/page1/") !== false) {
echo " id="item1";
}
Is something like this possible? Thanks

you could try it with the in Operator, but routing logic should be outside of the template file
you should do this logic in your Controller and set a variable "true".
controller.php
$uri = $_SERVER['REQUEST_URI'];
$item = null;
if ($uri == "/page1" ||strpos($uri, "/page1/") !== false) {
$item = "id=item1";
}
$this->render('MyBundle:mytwig.html.twig',array("item"=>$item));
mytwig.html.twig
{% if item %}
{{ item }} is only written if item is set
{% endif %}

This kind of logic does not belong in templates. Leave that code outside of your template and assign the result to a variable (instead of directly echoing it). Pass that variable to the Twig template. Output the variable.
Templates are exclusively for presentation, not for containing complicated logic code.

Related

How to properly count template usage?

I'm using Symfony 6.1 with Twig on PHP 8.1. I've already set up my complete layout including fragments/partials/components or whatever we call reusable pieces of the layout at the moment. These fragments include certain kinds of navigations, quotes, tabs and so on which are always supposed to look and work the same and usually only receive a variable with the same name as an array with a few options.
This is how I'm embedding a YouTube-Video for example:
{% set youtube_video = { 'id': 'dQw4w9WgXcQ', 'title': 'Secret Video (unlisted)', 'language': 'en' } %} {% include 'fragment/youtube_video.html.twig' %}
Most of these fragments can be used multiple times on one page (= in the main template of the view or within the base template/s). Some of them however are supposed to be used only once and using them multiple times would create layout issues (e.g. a navigation for mobile devices with a specific CSS id).
For other fragments I would like to have a counter to add a CSS id in addition to a normal class:
<div class="fragment_video" id="fragment_video_{{ counter }}> ... </div>
The question now is how I can count within a fragment template like 'fragment/youtube_video.html.twig' how often this template has been used in that page already. I don't see any Twig functions or anything within the "app" variable for that.
Now I could create a custom Twig function "counter" and call that with with a unique name:
<div class="fragment_video" id="fragment_video_{{ counter('fragment_video') }}> ... </div>
or
{% if counter('fragment_video') == 1 %} ... {% endif %}
BUT how would I store the current count per given name? I don't want to use $GLOBALS in Twig or rather Symfony and storing that information in the session would keep it past the current request. Is there another solution available?
This is how it would look like as a Twig function:
public function getCounter(string $name): int
{
$name = 'twig_counter_'.$name;
if (isset($GLOBALS[$name])) {
++$GLOBALS[$name];
} else {
$GLOBALS[$name] = 1;
}
return $GLOBALS[$name];
}
As suggested by #DarkBee the instance of a TwigExtension object can use properties to keep track of some information:
/**
* #var array<int>
*/
private array $count = [];
...
public function getCounter(string $name): int
{
if (isset($this->count[$name])) {
++$this->count[$name];
} else {
$this->count[$name] = 1;
}
return $this->count[$name];
}

Alternative to template_from_string for processing strings with calls to custom Twig functions

Is there an alternative to using template_from_string() for evaluating strings that contain calls to custom Twig functions (or any other complex Twig code for that matter)?
This is a simplified version of the code I have right now.
{% set content = {
'item_1' : {
'images' : {
'src': 'assets/images/img_1-600.jpg',
'srcset': "{{ assets('assets/images/img_1-600.jpg') }} 600w, {{ assets('assets/images/img_1-1200.jpg') }} 1200w",
}
}
# additional items follow
}
{% for data in content %}
<img src="{{ data.images.src }}" srcset="{{ include(template_from_string(data.images.srcset)) }}" alt="">
{% endfor %}
The assets() function simply returns a revisioned version of the static asset for the given path (i.e. assets('assets/images/img_1-600.jpg) renders as something like 'assets/images/img_1-600-a4c2254a6d.jpg).
The problems start with img srcset attribute which can become pretty complex and usually contains references to multiple assets that need to return revisioned values for static assets.
Now I know that I could modify the assets() function to support that kind of complex scenario but I'd like to keep things simple and let assets() only handle 1:1 transformations.
The only way to achieve this by using functionality provided by Twig seems to be template_from_string() combined with include, which in itself is not terrible but it does kind of look bulky for a simple operation as evaluating and rendering a string.
Not to mention that template_from_string requires StringLoaderExtension() to be loaded by default, which again I'd like to avoid using for performance reasons.
While the concatenation approach is not a bad idea, after much consideration I came to the conclusion that this is one of those places where having a custom Twig function makes much more sense.
The main argument in favor of using a function compared to simple concatenation is that with a function there is no need to worry about properly formating the template code (i.e. forget a space between the asset and the size descriptor in the srcset attribute value).
This approach also completely eliminates any need to use template_from_string() or additional extension dependencies.
Here is the final solution.
The template code, plain and simple, with plenty of overview.
{% set content = {
'item_1' : {
'images' : {
'src': 'assets/images/img-600.jpg',
'srcset': srcset([
[ assets('assets/images/img-600.jpg'), '600w' ],
[ assets('assets/images/img-800.jpg'), '800w' ],
[ assets('assets/images/img-1000.jpg'), '1000w' ],
[ assets('assets/images/img-1200.jpg'), '1200w' ]
]),
}
}
# additional items follow
}
{% for data in content %}
<img src="{{ data.images.src }}" srcset="{{ data.images.srcset }}" alt="">
{% endfor %}
The actual Twig function called srcset, that is used to generate a value for the srcset attribute from provided data in the above template.
public function srcset(array $srcset)
{
$output = [];
foreach ($srcset as $set) {
// Both parameters need to exist or the set isn't added to the output...
if (!(isset($set[0]) && isset($set[1]))) {
// ... just some exception handling that isn't of relevance for the question
// ...
continue;
}
$output[] = sprintf('%s %s', $set[0], $set[1]);
}
return implode(', ', $output);
}
To avoid any extra plugins, you could just concat the variables
{% set content = {
'item_1' : {
'images' : {
'src': 'assets/images/img_1-600.jpg',
'srcset': assets('assets/images/img_1-600.jpg')~' 600w,'~assets('assets/images/img_1-1200.jpg')~' 1200w',
}
}
} %}

ezplatform render links with url and object name from multi-relational content item in content type

does anyone know now to create a custom view type for ez platform? The default 3 have been exhausted and we need a new one for 'link'
Alternatively, does anyone know how to use the render( controller( with a custom template as this would also resolve out block right now.
Basically, we have a multi-relational field in a content object used and we need to print links to all the related contentIds, path works great but we cannot find a way to extract the name of the content object for the link without doing some fairly funky tpl logic of passing in params.
EG: As a hack for now we can pass in "embed_type" as a custom param with the render(controller("ez_content:viewAction" to pull in an alternate view for the content object for a specific content type and view type.
{% if embed_type is defined %}
{% include "embed/#{embed_type}.html.twig" %}
{% else %}
<h1>{{ ez_field_value( content, 'name') }}</h1>
{% endif %}
However, this is very ugly and all we really want to do is use 1 template for all content types, so all we need to do is loop through the relational field and print links (as the only thing available in the content field: "destination ids"). I am sure there used to be this option in the docs but i cannot find it anymore eg:
{% set links = ez_field_value( footer, "first_links_row" ).destinationContentIds%}
{% for id in links %}
{{ render(controller("ez_content:viewAction", {"contentId": id, "template": "link.html.twig"})) }}
{% endfor %}
Where the link.html.twig would simple print the link:
<a href="{{ path( "ez_urlalias", {"contentId": id} ) }}">
{{ ez_field_value( content, "name" ) }}
</a>
If using a custom tpl is not possible with the render (controller ( helper then a new custom view type would also fix this issue, but i cannot find documentation for either.
You can create a twig function that would do that. We have something like this:
Definition:
new Twig_SimpleFunction(
'content_name',
array($this, 'getContentName')
),
Implementation:
public function getContentName($content, $forcedLanguage = null)
{
if (!$content instanceof Content && !$content instanceof ContentInfo) {
$contentInfo = $this->repository->getContentService()->loadContentInfo($content);
} elseif ($content instanceof Content) {
$contentInfo = $content->contentInfo;
} else {
$contentInfo = $content;
}
return $this->translationHelper->getTranslatedContentNameByContentInfo($contentInfo, $forcedLanguage);
}
which enables you to provide either content id, content info or content itself, and it returns translated content name

Twig check if file exists

Hello so I am using slim framework and twig, and here is my current code in php:
$filename = '/path/to/foo.txt';
if (file_exists($filename)) {
echo "The file $filename exists";
} else {
echo "The file $filename does not exist";
}
Now I want to put the if statement in my template file. How can I use the file_exists function in my twig template so I can check whether a file exists?
You can create your own function or test and just pass the arguments to the PHP function.
$test = new Twig_SimpleTest('ondisk', function ($file) {
return file_exists($file);
});
And then in your template:
{% if filename is ondisk %}
blah
{% endif %}
Unfortunately is exists sounds weird in English. Perhaps a function would make more sense.
Creating a custom function is just fine if you really need to make the validation on template side. But Twig is not meant to be used that way.
You can just make the valitadion php side and pass a flag to your template:
PHP
$filename = '/path/to/foo.txt';
$file_exists = file_exists($filename);
// ...
$app->render(
'yourTemplate',
array( 'file_exists' => $file_exists )
);
TWIG
{% if file_exists %}
do stuff
{% endif %}
Disclaimer: I don't know the exact way to render a twig template using Slim (Symfony2 guy here), but it's same logic.
For those who use Symfony with Liip Image vich_uploader, and want to check, if a DB stored files exists or not (for example on image list / gallery), this is my solution:
{% set filePath = vich_uploader_asset(image, 'imageFile') %}
{% if filePath is not null %}
....
{% endif %}

Print a variable that contains html and twig on a twig template

I have a variable suppose that is:
$menustr; this variable contains code html and some twig parts for example:
$menustr .= '<li><a href="{{ path("'. $actual['direccion'] .'") }}" >'. $actual['nombre'] .'</a></li>';
I need that the browser take the code html and the part of twig that in this momen is the
"{{ path(~~~~~) }}"
I make a return where i send the variable called "$menustr" and after use the expresion "raw" for the html code but this dont make effective the twig code.
This is te return:
return $this->render('::menu.html.twig', array('menu' => $menustr));
and here is the template content:
{{ menu | raw }}
Twig can't render strings containing twig. There is not something like an eval function in Twig1..
What you can do is moving the path logic to the PHP stuff. The router service can generate urls, just like the path twig function does. If you are in a controller which extends the base Controller, you can simply use generateUrl:
$menuString .= '<li>'. $actual['nombre'] .'</li>';
return $this->render('::menu.html.twig', array(
'menu' => $menuString,
));
Also, when using menu's in Symfony, I recommend to take a look at the KnpMenuBundle.
EDIT: 1. As pointed by #PepaMartinec there is a function which can do this and it is called template_from_string
You can render Twig template stored in a varible using the template_from_string function.
Check this bundle: https://github.com/LaKrue/TwigstringBundle
This Bundle adds the possibility to render strings instead of files with the Symfony2 native Twig templating engine:
$vars = array('var'=>'x');
// render example string
$vars['test'] = $this->get('twigstring')->render('v {{ var }} {% if var is defined %} y {% endif %} z', $vars);
// output
v x y z
In your case i would be:
return $this->render('::menu.html.twig', array(
'menu' => $this->get('twigstring')->render($menustr, $vars)
));

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