'type' => 'file'Create a file upload field. Uses either the WordPress media uploader, or a basic uploader.
The file field takes the following custom parameters. Include them within the options array.
basic
Piklist allows for two different file upload fields in the WordPress admin, a Basic uploader and the standard Media uploader. To use the Media uploader, do not set this parameter at all.
NOTES:
The basic uploader is not supported in Widgets. Use the Media Uploader.
If the basic uploader is on a form that has validation, and the validation fails, the uploader will be empty.
Input: Array
Default: false
Example: 'basic' => true
button
Set button text.
'button' => 'Add File'modal_title
Set the title in the modal window (Media Uploader only)
'modal_title' => 'Add File(s)'preview_size
The preview size of the image
'preview_size' => 'medium'save
Save either the attachment ID or the url to the file to the database.
'save' => 'url'  piklist('field', array(
    'type' => 'file'
    ,'field' => 'my_upload_basic_field'
    ,'scope' => 'post_meta'
    ,'label' => 'Basic Upload Field'
    ,'options' => array(
      'basic' => true
    )
  ));
  piklist('field', array(
    'type' => 'file'
    ,'field' => 'my_upload_field'
    ,'scope' => 'post_meta'
    ,'label' => 'Media Uploader'
    ,'options' => array(
      'modal_title' => 'Add File(s)'
      ,'button' => 'Add'
    )
  ));
        
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