file Field Type

The file type represents a file input in your form.

Rendered as	input file field
Inherited options	disabled empty_data error_bubbling error_mapping label label_attr mapped read_only required
Parent type	form
Class	FileType

Basic Usage

Say you have this form definition:

$builder->add('attachment', 'file');

When the form is submitted, the attachment field will be an instance of UploadedFile. It can be used to move the attachment file to a permanent location:

use Symfony\Component\HttpFoundation\File\UploadedFile;

public function uploadAction()
{
    // ...

    if ($form->isValid()) {
        $someNewFilename = ...

        $form['attachment']->getData()->move($dir, $someNewFilename);

        // ...
    }

    // ...
}

The move() method takes a directory and a file name as its arguments. You might calculate the filename in one of the following ways:

// use the original file name
$file->move($dir, $file->getClientOriginalName());

// compute a random name and try to guess the extension (more secure)
$extension = $file->guessExtension();
if (!$extension) {
    // extension cannot be guessed
    $extension = 'bin';
}
$file->move($dir, rand(1, 99999).'.'.$extension);

Using the original name via getClientOriginalName() is not safe as it could have been manipulated by the end-user. Moreover, it can contain characters that are not allowed in file names. You should sanitize the name before using it directly.

Read the cookbook for an example of how to manage a file upload associated with a Doctrine entity.

Inherited Options

These options inherit from the form type:

disabled

2.1 新版功能: The disabled option was introduced in Symfony 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.

empty_data

type: mixed

The default value is null.

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,
    'empty_value' => '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.

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.

error_mapping

2.1 新版功能: The error_mapping option was introduced in Symfony 2.1.

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 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 or ArrayAccess 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.

label

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:

• Twig

  {{ form_label(form.name, 'Your name') }}
  

• PHP

  echo $view['form']->label(
      $form['name'],
      'Your name'
  );
  

label_attr

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:

• Twig

  {{ form_label(form.name, 'Your name', {'label_attr': {'class': 'CUSTOM_LABEL_CLASS'}}) }}
  

• PHP

  echo $view['form']->label(
      $form['name'],
      'Your name',
      array('label_attr' => array('class' => 'CUSTOM_LABEL_CLASS'))
  );
  

mapped

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.

read_only

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.

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.

注解

The required option also affects how empty data for each field is handled. For more details, see the empty_data option.

Form Variables

Variable	Type	Usage
type	string	The type variable is set to file, in order to render as a file input field.