twig_reference.rst

.. index::
   single: Forms; Twig form function reference

Twig Template Form Function Reference

This reference manual covers all the possible Twig functions available for rendering forms. There are several different functions available, and each is responsible for rendering a different part of a form (e.g. labels, errors, widgets, etc).

form_label(view, label, variables)

Renders the label for the given field. You can optionally pass the specific label you want to display as the second argument.

{{ form_label(form.name) }}

{# The two following syntaxes are equivalent #}
{{ form_label(form.name, 'Your Name', {'label_attr': {'class': 'foo'}}) }}
{{ form_label(form.name, null, {'label': 'Your name', 'label_attr': {'class': 'foo'}}) }}

See ":ref:`twig-reference-form-variables`" to learn about the variables argument.

form_errors(view)

Renders any errors for the given field.

{{ form_errors(form.name) }}

{# render any "global" errors #}
{{ form_errors(form) }}

form_widget(view, variables)

Renders the HTML widget of a given field. If you apply this to an entire form or collection of fields, each underlying form row will be rendered.

{# render a widget, but add a "foo" class to it #}
{{ form_widget(form.name, {'attr': {'class': 'foo'}}) }}

The second argument to form_widget is an array of variables. The most common variable is attr, which is an array of HTML attributes to apply to the HTML widget. In some cases, certain types also have other template-related options that can be passed. These are discussed on a type-by-type basis. The attributes are not applied recursively to child fields if you're rendering many fields at once (e.g. form_widget(form)).

See ":ref:`twig-reference-form-variables`" to learn more about the variables argument.

form_row(view, variables)

Renders the "row" of a given field, which is the combination of the field's label, errors and widget.

{# render a field row, but display a label with text "foo" #}
{{ form_row(form.name, {'label': 'foo'}) }}

The second argument to form_row is an array of variables. The templates provided in Symfony only allow to override the label as shown in the example above.

See ":ref:`twig-reference-form-variables`" to learn about the variables argument.

form_rest(view, variables)

This renders all fields that have not yet been rendered for the given form. It's a good idea to always have this somewhere inside your form as it'll render hidden fields for you and make any fields you forgot to render more obvious (since it'll render the field for you).

{{ form_rest(form) }}

form_enctype(view)

If the form contains at least one file upload field, this will render the required enctype="multipart/form-data" form attribute. It's always a good idea to include this in your form tag:

<form action="{{ path('form_submit') }}" method="post" {{ form_enctype(form) }}>

More about Form "Variables"

In almost every Twig function above, the final argument is an array of "variables" that are used when rendering that one part of the form. For example, the following would render the "widget" for a field, and modify its attributes to include a special class:

{# render a widget, but add a "foo" class to it #}
{{ form_widget(form.name, { 'attr': {'class': 'foo'} }) }}

The purpose of these variables - what they do & where they come from - may not be immediately clear, but they're incredibly powerful. Whenever you render any part of a form, the block that renders it makes use of a number of variables. By default, these blocks live inside form_div_layout.html.twig.

Look at the form_label as an example:

{% block form_label %}
    {% if not compound %}
        {% set label_attr = label_attr|merge({'for': id}) %}
    {% endif %}
    {% if required %}
        {% set label_attr = label_attr|merge({'class': (label_attr.class|default('') ~ ' required')|trim}) %}
    {% endif %}
    {% if label is empty %}
        {% set label = name|humanize %}
    {% endif %}
    <label{% for attrname, attrvalue in label_attr %} {{ attrname }}="{{ attrvalue }}"{% endfor %}>{{ label|trans({}, translation_domain) }}</label>
{% endblock form_label %}

This block makes use of several variables: compound, label_attr, required, label, name and translation_domain. These variables are made available by the form rendering system. But more importantly, these are the variables that you can override when calling form_label (since in this example, you're rendering the label).

The exact variables available to override depends on which part of the form you're rendering (e.g. label versus widget) and which field you're rendering (e.g. a choice widget has an extra expanded option). If you get comfortable with looking through form_div_layout.html.twig, you'll always be able to see what options you have available.

Tip

Behind the scenes, these variables are made available to the FormView object of your form when the form component calls buildView and buildViewBottomUp on each "node" of your form tree. To see what "view" variables a particularly field has, find the source code for the form field (and its parent fields) and look at the above two functions.

Note

If you're rendering an entire form at once (or an entire embedded form), the variables argument will only be applied to the form itself and not its children. In other words, the following will not pass a "foo" class attribute to all of the child fields in the form:

{# does **not** work - the variables are not recursive #}
{{ form_widget(form, { 'attr': {'class': 'foo'} }) }}