choice Field Type
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choice Field Type
A multi-purpose field used to allow the user to "choose" one or more options.
It can be rendered as a select
tag, radio buttons, or checkboxes.
To use this field, you must specify either the choice_list
or choices
option.
Rendered as | can be various tags (see below) |
Options | |
Inherited options | |
Parent type | form (if expanded), field otherwise |
Class | ChoiceType |
Example Usage
The easiest way to use this field is to specify the choices directly via the
choices
option. The key of the array becomes the value that's actually
set on your underlying object (e.g. m
), while the value is what the
user sees on the form (e.g. Male
).
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$builder->add('gender', 'choice', array(
'choices' => array('m' => 'Male', 'f' => 'Female'),
'required' => false,
));
By setting multiple
to true, you can allow the user to choose multiple
values. The widget will be rendered as a multiple select
tag or a series
of checkboxes depending on the expanded
option:
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$builder->add('availability', 'choice', array(
'choices' => array(
'morning' => 'Morning',
'afternoon' => 'Afternoon',
'evening' => 'Evening',
),
'multiple' => true,
));
You can also use the choice_list
option, which takes an object that can
specify the choices for your widget.
Select tag, Checkboxes or Radio Buttons
This field may be rendered as one of several different HTML fields, depending
on the expanded
and multiple
options:
element type | expanded | multiple |
---|---|---|
select tag | false | false |
select tag (with multiple attribute) |
false | true |
radio buttons | true | false |
checkboxes | true | true |
Field Options
choices
type: array
default: array()
This is the most basic way to specify the choices that should be used
by this field. The choices
option is an array, where the array key
is the item value and the array value is the item's label:
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$builder->add('gender', 'choice', array(
'choices' => array('m' => 'Male', 'f' => 'Female')
));
choice_list
type: Symfony
This is one way of specifying the options to be used for this field.
The choice_list
option must be an instance of the ChoiceListInterface
.
For more advanced cases, a custom class that implements the interface
can be created to supply the choices.
multiple
type: Boolean
default: false
If true, the user will be able to select multiple options (as opposed
to choosing just one option). Depending on the value of the expanded
option, this will render either a select tag or checkboxes if true and
a select tag or radio buttons if false. The returned value will be an array.
expanded
type: Boolean
default: false
If set to true, radio buttons or checkboxes will be rendered (depending
on the multiple
value). If false, a select element will be rendered.
preferred_choices
type: array
default: array()
If this option is specified, then a sub-set of all of the options will be moved to the top of the select menu. The following would move the "Baz" option to the top, with a visual separator between it and the rest of the options:
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$builder->add('foo_choices', 'choice', array(
'choices' => array('foo' => 'Foo', 'bar' => 'Bar', 'baz' => 'Baz'),
'preferred_choices' => array('baz'),
));
Note that preferred choices are only meaningful when rendering as a select
element (i.e. expanded
is false). The preferred choices and normal choices
are separated visually by a set of dotted lines (i.e. -------------------
).
This can be customized when rendering the field:
1
{{ form_widget(form.foo_choices, { 'separator': '=====' }) }}
1
<?php echo $view['form']->widget($form['foo_choices'], array('separator' => '=====')) ?>
empty_value
type: string
or Boolean
This option determines whether or not a special "empty" option (e.g. "Choose an option")
will appear at the top of a select widget. This option only applies if both
the expanded
and multiple
options are set to false.
Add an empty value with "Choose an option" as the text:
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$builder->add('states', 'choice', array( 'empty_value' => 'Choose an option', ));
Guarantee that no "empty" value option is displayed:
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$builder->add('states', 'choice', array( 'empty_value' => false, ));
If you leave the empty_value
option unset, then a blank (with no text)
option will automatically be added if and only if the required
option
is false:
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// a blank (with no text) option will be added
$builder->add('states', 'choice', array(
'required' => false,
));
Inherited options
These options inherit from the field type:
required
type: Boolean
default: true
If true, an HTML5 required attribute will be rendered. The corresponding
label
will also render with a required
class.
This is superficial and independent from validation. At best, if you let Symfony guess your field type, then the value of this option will be guessed from your validation information.
label
type: string
default: The label is "guessed" from the field name
Sets the label that will be used when rendering the field. The label can also be directly set inside the template:
1
{{ form_label(form.name, 'Your name') }}
read_only
2.1
The read_only
option was changed in 2.1 to render as a readonly
HTML attribute. Previously, it rendered as a disabled
attribute.
Use the disabled option if you need the old behavior.
type: Boolean
default: false
If this option is true, the field will be rendered with the readonly
attribute so that the field is not editable.
disabled
2.1
The disabled
option is new in version 2.1
type: boolean
default: false
If you don't want a user to modify the value of a field, you can set
the disabled option to true. Any submitted value will be ignored.
error_bubbling
type: Boolean
default: false
unless the form is compound
If true, any errors for this field will be passed to the parent field or form. For example, if set to true on a normal field, any errors for that field will be attached to the main form, not to the specific field.
2.1
The error_mapping
option is new to Symfony 2.1.
error_mapping
type: array
default: empty
This option allows you to modify the target of a validation error.
Imagine you have a custom method named matchingCityAndZipCode
that validates
whether the city and zip code match. Unfortunately, there is no "matchingCityAndZipCode"
field in your form, so all that Symfony can do is display the error on top
of the form.
With customized error mapping, you can do better: map the error to the city field so that it displays above it:
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public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'error_mapping' => array(
'matchingCityAndZipCode' => 'city',
),
));
}
Here are the rules for the left and the right side of the mapping:
- The left side contains property paths.
- If the violation is generated on a property or method of a class, its path is simply "propertyName".
- If the violation is generated on an entry of an
array
orArrayAccess
object, the property path is[indexName]
. - You can construct nested property paths by concatenating them, separating
properties by dots. For example:
addresses[work].matchingCityAndZipCode
- The left side of the error mapping also accepts a dot
.
, which refers to the field itself. That means that any error added to the field is added to the given nested field instead. - The right side contains simply the names of fields in the form.
mapped
type: boolean
If you wish the field to be ignored when reading or writing to the object, you
can set the mapped
option to false
.
virtual
type: boolean
default: false
This option determines if the form will be mapped with data. This can be useful if you need a form to structure the view. See How to use the Virtual Form Field Option.
by_reference
type: Boolean
default: true
In most cases, if you have a name
field, then you expect setName
to be called on the underlying object. In some cases, however, setName
may not be called. Setting by_reference
ensures that the setter is
called in all cases.
To explain this further, here's a simple example:
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$builder = $this->createFormBuilder($article);
$builder
->add('title', 'text')
->add(
$builder->create('author', 'form', array('by_reference' => ?))
->add('name', 'text')
->add('email', 'email')
)
If by_reference
is true, the following takes place behind the scenes
when you call bind
on the form:
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$article->setTitle('...');
$article->getAuthor()->setName('...');
$article->getAuthor()->setEmail('...');
Notice that setAuthor
is not called. The author is modified by reference.
If you set by_reference
to false, binding looks like this:
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$article->setTitle('...');
$author = $article->getAuthor();
$author->setName('...');
$author->setEmail('...');
$article->setAuthor($author);
So, all that by_reference=false
really does is force the framework to
call the setter on the parent object.
Similarly, if you're using the collection
form type where your underlying collection data is an object (like with Doctrine's
ArrayCollection
), then by_reference
must be set to false
if you
need the setter (e.g. setAuthors
) to be called.
empty_data
type: mixed
default: array()
if multiple
or expanded
, ''
otherwise
This option determines what value the field will return when the empty_value
choice is selected.
The true default value of this option depends on the field options:
- If
compound
istrue
anddata_class
is set, thennew $data_class()
; - If
compound
istrue
and nodata_class
is set, thenarray()
; - If
compound
isfalse
, thennull
.
Tip
The compound
option is set to true
when the field actually represents
a collection of fields (e.g. a form of fields).
For example, if you want the gender
field to be set to null
when no
value is selected, you can do it like this:
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$builder->add('gender', 'choice', array(
'choices' => array(
'm' => 'Male',
'f' => 'Female'
),
'required' => false,
'empty_value' => 'Choose your gender',
'empty_data' => null
));
Note
If you want to set the empty_data
option for your entire form class,
see the cookbook article How to configure Empty Data for a Form Class