HTML in Symfony2 form labels instead of plain text

I am trying to implement something like this:

<div>
    <input type="checkbox" name="checkbox" id="checkbox_id" />
    <label for="checkbox_开发者_如何学Cid">I agree to the <a href="/tos">Terms of Service</a></label>
</div>

The closest I've come to implement this is through:

<div>
    {{ form_widget(form.agreeWithTos) }}
    <label for="{{ form.agreeWithTos.vars.id }}">I agree to the <a href="#">Terms of Service</a></label>
</div>

Is there a better way? Having to specify {{ form.agreeWithTos.vars.id }} is inelegant. :)

Solved this problem using the following code in my form-theme:

{# ---- form-theme.html.twig #}
{% block checkbox_row %}
{% spaceless %}
<div>
    {{ form_errors(form) }}

    <label class="checkbox" for="{{ form.vars.id }}">
        {{ form_widget(form) }}
        {{ label|default(form_label(form)) | raw }}
    </label>
</div>
{% endspaceless %}
{% endblock %}

in your Form-Template you can then use:

{% form_theme form '::form-theme.html.twig' %}

{{form_row(form.termsOfServiceAccepted, {
        'label' : 'I have read and agree to the <a href="#">Terms and conditions</a>'
    })
}}

this way, the block from the form-theme would apply to any checkbox on the page. If you need to also use the default-theme, you can add a parameter to enable special-rendering:

{# ---- form-theme.html.twig #}
{% block checkbox_row %}
{% spaceless %}
    {% if not useTosStyle %}
        {{ parent() }}
    {% else %}
        {# ... special rendering ... #}
    {% endif %}
{% endspaceless %}
{% endblock %}

which would be used like this:

{% form_theme form '::form-theme.html.twig' %}

{{form_row(form.termsOfServiceAccepted, {
        'useTosStyle' : true,
        'label' : 'I have read and agree to the <a href="#">Terms and conditions</a>'
    })
}}

Thanks to a recent commit to Symfony, you can use label_html from Symfony 5.1 onward:

{{ form_label(
    form.privacy,
    'I accept the <a href="' ~ path('privacy') ~ '">privacy terms</a>.', 
    {
        'label_html': true,
    },
) }}

I've been beating my head over this then had a eureka moment. The easiest way to do this–BY FAR–is to create a Twig extension.

Here's my Twig code:

{# twig example #}
{% block form_label %}
    {% set label = parent() %}
    {{ label|unescape|raw }}
{% endblock %}

and PHP:

<?php
new Twig_SimpleFilter('unescape', function($value) {
    return html_entity_decode($value);
});

A couple notes:

• This unescapes all previously escaped code. You should definitely re-escape afterwards as necessary.
• This requires an extends tag for your target form theme in your own custom form theme which you can use in your subsequent forms. Put the twig code in a custom form theme and replace references to your other form theme/themes with this one.

Overall this is the fewest lines of code for the biggest and best outcome that I've been able to find. It's also ultra-portable and DRY: You can extend any form theme and the label will change without you changing the rest of your code.

Another very simple approach is to override the form theme directly in the template which renders the form. Using {% form_theme form _self %} it is as simple as this:

{% form_theme form _self %}

{% block form_label %}
    {{ label | raw }}
{% endblock %}

{{ form_start(form) }}

See the corresponding section in the docs:

https://symfony.com/doc/current/form/form_customization.html#method-1-inside-the-same-template-as-the-form

The easiest way to customize the [...] block is to customize it directly in the template that's actually rendering the form.

By using the special {% form_theme form _self %} tag, Twig looks inside the same template for any overridden form blocks. [...]

The disadvantage of this method is that the customized form block can't be reused when rendering other forms in other templates. In other words, this method is most useful when making form customizations that are specific to a single form in your application. If you want to reuse a form customization across several (or all) forms in your application, read on to the next section.

Another approach is to use a simple Twig replacement:

{% set formHtml %}
   {{ form(oForm) }}
{% endset %}

{{ formHtml|replace({'[link]': '<a href=" ... ">', '[/link]': '</a>'})|raw }}

In your form, you have something like this in order to make it work:

$formBuilder->add('conditions', CheckboxType::class, [
        'label' => 'Yes, I agree with the [link]terms and conditions[/link].'
    ]
);

Of course, you may change [link] to anything else. Please note that you do not use HTML tags ;-)

I think you are looking for form theming. That way you are able to style each part of form, in an independent file, anyway you want and then just render it in "elegant" way, row by row with {{ form_row(form) }} or simply with {{ form_widget(form) }}. It's really up to you how you set it up.

Symfony 4.2

TWIG:

{% block main %} 
   .... 
   {% form_theme form _self %}
...
 {{ form_row(form.policy, {'label': 'security.newPassword.policy'|trans({"%policyLink%":policyLink, "%termsLink%":termsLink})}) }}
   ...
{% endblock %}

{% block checkbox_radio_label %}
    <label{% with { attr: label_attr } %}{{ block('attributes') }}{% endwith %}>
        {{- widget|raw }} {{ label|unescape|raw }}
    </label>
{% endblock checkbox_radio_label %}

PHP:

use Twig\Extension\AbstractExtension;
use Twig\TwigFilter;

class AppExtension extends AbstractExtension
{
    public function getFilters()
    {
        return [
            new TwigFilter('unescape', function ($value) {
                return html_entity_decode($value);
            }),
        ];
    }
}

So form theming is pretty complicated. The easiest thing I've found is to just suppress the field's label ('label'=> false in Symfony form class) and then just add the html label in the twig html.

You could leverage form theming in another way: you could move the <label> tag outside the form_label() function.

Create a custom form theme, and for checkboxes only move the <label> tag outside the form_label function:

{% block checkbox_row %}
    <label>{{ form_label(form) }}</label>
    {{ form_errors(form) }}
    {{ form_widget(form) }}
{% endblock checkbox_row %}

{% block checkbox_label %}
    {{ label }}
{% endblock checkbox_label %}

Now, in your teplate, override the label of your checkbox, and thus effectively inject HTML into the label function:

{% form_theme form 'yourtheme.html.twig' _self %}

{% block _your_TOS_checkbox_label %}
    I agree with <a href="#" target="_blank">terms and conditions</a>
{% endblock _your_TOS_checkbox_label %}