$form_helper->file_field( $object_name, [ $column_name = null], [ $options = array()])

Description:
Returns an input tag of the “file” type tailored for accessing the attribute identified by $column_name on the object $object_name.
Additional options are to be passed as an array with $options.
Options:

• 'disabled' - If set to true, the user will not be able to use this input.
• 'size' - The number of visible characters that will fit in the input.
• 'maxlength' - The maximum number of characters that the browser will allow the user to enter.

If you are using file uploads then you will also need to set the multipart option for the form:

<?= $form_helper->form_to(array('action'=>'post'),array('multipart'=>true)); ?>
<label for="file">File to Upload</label> 
<?= $form_helper->file_field_tag('file'); ?> 
<?= $form_helper->submit_tag(); ?> 
<?= $form_helper->end_form_tag(); ?>

Example:

$form_helper->file_field("post", "file_name", array("size" => 20));

produces this PHP code:

<input type="file" id="post_file_name" name="post[file_name]" size="20" value="{post.file_name}" />

Syntax:

$form_helper_tag->file_field_tag( $name, [ $value ], [ $options ])

Description:
Produces an input tag of the “file” type. Processing of this input will have to be done in helper code or in the controller.
Options:

• 'disabled' - If set to true, the user will not be able to use this input.
• 'size' - The number of visible characters that will fit in the input.
• 'maxlength' - The maximum number of characters that the browser will allow the user to enter.

If you are using file uploads then you will also need to set the multipart option for the form:

<?= $form_tag_helper->form_tag(array('method'=>'post'),array('multipart'=>true)); ?>
<label for="file">File to Upload</label> 
<?= $form_tag_helper->file_field_tag('file'); ?> 
<?= $form_tag_helper->submit_tag(); ?> 
<?= $form_tag_helper->end_form_tag(); ?>