发布于 2015-08-27 16:46:41 | 163 次阅读 | 评论: 0 | 来源: 网络整理
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 | |
Overridden options | |
Inherited options | |
Parent type | form |
Class | ChoiceType |
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
).
$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:
$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.
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 |
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:
$builder->add('gender', 'choice', array(
'choices' => array('m' => 'Male', 'f' => 'Female')
));
小技巧
When the values to choose from are not integers or strings (but e.g. floats or booleans), you should use the choice_list option instead. With this option you are able to keep the original data format which is important to ensure that the user input is validated properly and useless database updates caused by a data type mismatch are avoided.
type: ChoiceListInterface
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.
With this option you can also allow float values to be selected as data.
use SymfonyComponentFormExtensionCoreChoiceListChoiceList;
// ...
$builder->add('status', 'choice', array(
'choice_list' => new ChoiceList(array(1, 0.5), array('Full', 'Half'))
));
2.6 新版功能: The placeholder
option was introduced in Symfony 2.6 in favor of
empty_value
, which is available prior to 2.6.
2.3 新版功能: Since Symfony 2.3, empty values are also supported if the expanded
option is set to true.
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 the
multiple
option is set to false.
Add an empty value with “Choose an option” as the text:
$builder->add('states', 'choice', array(
'placeholder' => 'Choose an option',
));
Guarantee that no “empty” value option is displayed:
$builder->add('states', 'choice', array(
'placeholder' => false,
));
If you leave the placeholder
option unset, then a blank (with no text)
option will automatically be added if and only if the required
option
is false:
// a blank (with no text) option will be added
$builder->add('states', 'choice', array(
'required' => false,
));
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.
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.
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:
$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:
{{ form_widget(form.foo_choices, { 'separator': '=====' }) }}
<?php echo $view['form']->widget($form['foo_choices'], array('separator' => '=====')) ?>
type: boolean
default: same value as expanded
option
This option specifies if a form is compound. The value is by default
overridden by the value of the expanded
option.
type: mixed
The actual default value of this option depends on other field options:
multiple
is false
and expanded
is false
, then ''
(empty string);array()
(empty array).This option determines what value the field will return when the submitted value is empty.
But you can customize this to your needs. For example, if you want the
gender
choice field to be explicitly set to null
when no value is
selected, you can do it like this:
$builder->add('gender', 'choice', array(
'choices' => array(
'm' => 'Male',
'f' => 'Female'
),
'required' => false,
'placeholder' => 'Choose your gender',
'empty_data' => null
));
注解
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.
type: boolean
default: false
Set that error on this field must be attached to the field instead of the parent field (the form in most cases).
These options inherit from the form type:
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:
$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 submit()
(or handleRequest()
) on the form:
$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, submitting looks like this:
$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 adder and remover (e.g. addAuthor()
and removeAuthor()
) to be called.
type: mixed
default: Defaults to field of the underlying object (if there is one)
When you create a form, each field initially displays the value of the corresponding property of the form’s domain object (if an object is bound to the form). If you want to override the initial value for the form or just an individual field, you can set it in the data option:
$builder->add('token', 'hidden', array(
'data' => 'abcdef',
));
注解
The default values for form fields are taken directly from the
underlying data structure (e.g. an entity or an array).
The data
option overrides this default value.
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.
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:
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'error_mapping' => array(
'matchingCityAndZipCode' => 'city',
),
));
}
Here are the rules for the left and the right side of the mapping:
propertyName
;array
or ArrayAccess
object, the property path is [indexName]
;addresses[work].matchingCityAndZipCode
;.
, which refers
to the field itself. That means that any error added to the field is added
to the given nested field instead;2.3 新版功能: The inherit_data
option was introduced in Symfony 2.3. Before, it
was known as virtual
.
type: boolean
default: false
This option determines if the form will inherit data from its parent form. This can be useful if you have a set of fields that are duplicated across multiple forms. See How to Reduce Code Duplication with “inherit_data”.
警告
When a field has the inherit_data
option set, it uses the data of the
parent form as is. This means that Data Transformers
won’t be applied to that field.
type: string
default: The label is “guessed” from the field name
Sets the label that will be used when rendering the field. Setting to false will suppress the label. The label can also be directly set inside the template:
{{ form_label(form.name, 'Your name') }}
echo $view['form']->label(
$form['name'],
'Your name'
);
type: array
default: array()
Sets the HTML attributes for the <label>
element, which will be used when
rendering the label for the field. It’s an associative array with HTML attribute
as a key. This attributes can also be directly set inside the template:
{{ form_label(form.name, 'Your name', {'label_attr': {'class': 'CUSTOM_LABEL_CLASS'}}) }}
echo $view['form']->label(
$form['name'],
'Your name',
array('label_attr' => array('class' => 'CUSTOM_LABEL_CLASS'))
);
type: boolean
default: true
If you wish the field to be ignored when reading or writing to the object, you
can set the mapped
option to false
.
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.
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.
注解
The required option also affects how empty data for each field is handled. For more details, see the empty_data option.
Variable | Type | Usage |
---|---|---|
multiple | Boolean |
The value of the multiple option. |
expanded | Boolean |
The value of the expanded option. |
preferred_choices | array |
A nested array containing the ChoiceView objects of
choices which should be presented to the user with priority. |
choices | array |
A nested array containing the ChoiceView objects of
the remaining choices. |
separator | string |
The separator to use between choice groups. |
placeholder | mixed |
The empty value if not already in the list, otherwise
null . |
is_selected | callable |
A callable which takes a ChoiceView and the selected value(s)
and returns whether the choice is in the selected value(s). |
placeholder_in_choices | Boolean |
Whether the empty value is in the choice list. |
小技巧
It’s significantly faster to use the selectedchoice(selected_value) test instead when using Twig.