Toggle html validation globally - symfony

Question

I've made a couple of twig extensions but I'm stumped on this one.
I have the following template logic that I want to make into an extension.
I need reuse this logic into many different forms instead of copying and pasting the following code everywhere:
{% if html5validation is not defined %}
{{ form_start(some_form) }}
{% else %}
{% if html5validation %}
{{ form_start(some_form) }}
{% else %}
{{ form_start
(
company, {'attr': {'novalidate': 'novalidate'}}
)
}}
{% endif %}
{% endif %}
With the above code from the controller I can do the following to turn the html5 validator on and off:
$this->render(..., array(html5validation => false));
I want put the template logic into the twig extension below...
I just don't know if it's possible to implement what I've done above in a twig extension.
class HTML5Validation extends \Twig_Extension
{
public function getFunctions()
{
return array(
new \Twig_SimpleFunction('html5validation', array($this, 'setValidation')),
);
}
public function setValidation($boolean)
{
//Implement the same logic as the twig template.
}
public function getName()
{
return 'html5validator';
}
}

Answer 1

The short answer is no - you can't do this using a twig extension, it's not what they're meant for.
Looking at your template fragment I'd say you need to customise the form_start block. To do this see Symfony Form Theming and How to customise form rendering.
EDIT: This solution does not work if your customised code requires local twig variables - only global twig variables are available for form theming. You can define your own twig globals in config.yml or in a twig extension.
For example, to override form_start globally, you find the default definition of the form_start block in form_div_layout.html.twig, copy it into your own form theme file e.g. YourBundle/Form/fields.html.twig, modify it as required and and update the twig configuration to apply your form theme file. Something like this:
{# src/YourBundle/Form/fields.html.twig #}
{% extends 'form_div_layout.html.twig' %}
{% block form_start -%}
{% if html5validation is not defined %}
{{ parent() }}
{% else %}
{% if html5validation %}
{{ parent() }}
{% else %}
{{ parent
(
company, {'attr': {'novalidate': 'novalidate'}}
)
}}
{% endif %}
{% endif %}
{%- endblock form_start %}
Config:
# app/config/config.yml
twig:
form:
resources:
- 'YourBundle:Form:fields.html.twig'

Answer 2

I actually found a better way to do what I wanted.
As a plus it works globally instead of having to populate more fields into your controller!
In YourBundle/Resources/views/validation.toggle.html.twig
{% extends 'form_div_layout.html.twig' %}
{% block form_start -%}
{% if html5validation is defined and html5validation == false %}
{% set attr = attr|merge({'novalidate': 'novalidate'}) %}
{% endif %}
{{ parent() }}
{%- endblock form_start %}
Then if you want to turn off html5 validation across the whole website:
# app/config/config.yml
twig:
global:
html5validation: false
Or
Even better just use it in your dev_config.yml if you want validation on by default on production mode but the ability to toggle validation on and off for dev mode.
# app/config/dev_config.yml
twig:
global:
html5validation: false
resources:
- 'YourBundle::validation.toggle.html.twig'
Finally use it in your twig template normally:
{% form_theme your_form 'YourBundle::validation.toggle.html.twig' %}
form_start(your_form)
Reusable and non invasive, exactly like I wanted it. :)
I got the hint from:
https://github.com/symfony/symfony/issues/11409#issuecomment-49358377

Answer 3

In the absence of a more elegant solution, you can always put the twig fragment given in your question into a separate file and use twig include from your various forms. The included fragment has access to the variables from the surrounding context:
{# YourBundle/Resources/views/form_start.html.twig #}
{% if html5validation is not defined %}
{{ form_start(some_form) }}
{% else %}
{% if html5validation %}
{{ form_start(some_form) }}
{% else %}
{{ form_start
(
company, {'attr': {'novalidate': 'novalidate'}}
)
}}
{% endif %}
{% endif %}
Then in the twig file for the form:
{% include 'YourBundle::form_start.html.twig' %}
If you typically pass a 'form' variable into render() in your controller(s) then you can use that in your form_start fragment. Otherwise you can pass the appropriate form in as a variable:
{% include 'YourBundle::form_start.html.twig' with {'form': localForm} %}