Creating new metadata for attachments ?

An attachment is a post so you can save a post meta for each image

To setup you just need:

update_post_meta(
    $post->ID,
    Name_of_the_variable,
    Value_of_the_variable
)

And to retrieve it:

get_post_meta(
    $post->ID,
    Name_of_the_variable
)

For example:

update_post_meta(
    $post->ID,
    'my_custom_parameter',
    'my_parameter_value'
)

Whish it helps.

Thanks for the answer.
Here is my code to add the input in the media uplaod screen:

function tdv_integration_attachment_fields_to_edit( $form_fields, $post ) {
  if(get_option('hi_enabledForDefault') == 1)
      $checkedHighslide = 'checked="checked" ';>
   $my_form_fields = array(
      'tdv' => array(
         'label'     => __('Enlargement', HI_TEXTDOMAIN),
         'input'     => 'html',
         'html'      => "
            <input type='checkbox' name='tdv-{$post->ID}' id='tdv-{$post->ID}' data-user-setting='tdv-{$post->ID}' data-setting='tdv-{$post->ID}' $checkedHighslide />
            <label for='tdv-{$post->ID}'>" . __('Use tdv', HI_TEXTDOMAIN) . "</label>" )
    );
    if( $post->post_mime_type == 'image/jpeg' OR  $post->post_mime_type == 'image/gif' OR $post->post_mime_type == 'image/png' OR $post->post_mime_type == 'image/tiff')
     {
	  return array_merge( $form_fields, $my_form_fields );
	  }
    else
      return $form_fields;
}
add_filter( 'attachment_fields_to_edit', 'tdv_integration_attachment_fields_to_edit', 66, 2 );

And I can’t find a way to retrieve if my input is checked or not…
Anyone would know ?

add_filter('attachment_fields_to_edit', 'my_image_attachment_fields_to_edit', 10, 2);
add_filter('attachment_fields_to_save', 'my_image_attachment_fields_to_save', 10, 2); 

function my_image_attachment_fields_to_edit($form_fields, $post) {
    $value = get_post_meta($post->ID, '_drink', true);
    $form_fields['drink'] = array(
        'label' => __('Drink'),
        'input' => 'html',
        'html'  => "<input type='radio' name='attachments[{$post->ID}][drink]' value='tea' ". (( $value == 'tea' ) ? "checked='checked'" : "" ) . "/> tea
		    <input type='radio' name='attachments[{$post->ID}][drink]' value='coffee' ". (( $value == 'coffee' ) ? "checked='checked'" : "" ) . "/> coffee",
        'value' => $value,
    );
    return $form_fields;
}

function my_image_attachment_fields_to_save($post, $attachment) {
    if( isset($attachment['drink']) )
        update_post_meta($post['ID'], '_drink', $attachment['drink']);
    return $post;
}

This works for me. Hope it will help ??

VJPO,

I am using a bit of your code because it was exactly what I was looking for…unfortunately I can’t get the radio buttons to actually show up in the Edit Media page. How did you do that?

Thank you in advance!

Scratch that – I had forgotten to rename the functions to match the filter call. Nevermind. Thanks for sharing this code!

@coolarts & vjpo: many thanks for your help!