media_upload_type_url_form( string $type = null, object $errors = null, integer $id = null )

function media_upload_type_url_form($type = null, $errors = null, $id = null) {
	if ( null === $type )
		$type = 'image';

	media_upload_header();

	$post_id = isset( $_REQUEST['post_id'] ) ? intval( $_REQUEST['post_id'] ) : 0;

	$form_action_url = admin_url("media-upload.php?type=$type&tab=type&post_id=$post_id");
	/** This filter is documented in wp-admin/includes/media.php */
	$form_action_url = apply_filters( 'media_upload_form_url', $form_action_url, $type );
	$form_class = 'media-upload-form type-form validate';

	if ( get_user_setting('uploader') )
		$form_class .= ' html-uploader';
?>

<form enctype="multipart/form-data" method="post" action="<?php echo esc_url( $form_action_url ); ?>" class="<?php echo $form_class; ?>" id="<?php echo $type; ?>-form">
<input type="hidden" name="post_id" id="post_id" value="<?php echo (int) $post_id; ?>" />
<?php wp_nonce_field('media-form'); ?>

<h3 class="media-title"><?php _e('Insert media from another website'); ?></h3>

<script type="text/javascript">
var addExtImage = {

	width : '',
	height : '',
	align : 'alignnone',

	insert : function() {
		var t = this, html, f = document.forms[0], cls, title = '', alt = '', caption = '';

		if ( '' == f.src.value || '' == t.width )
			return false;

		if ( f.alt.value )
			alt = f.alt.value.replace(/'/g, '&#039;').replace(/"/g, '&quot;').replace(/</g, '&lt;').replace(/>/g, '&gt;');

<?php
	/** This filter is documented in wp-admin/includes/media.php */
	if ( ! apply_filters( 'disable_captions', '' ) ) {
		?>
		if ( f.caption.value ) {
			caption = f.caption.value.replace(/\r\n|\r/g, '\n');
			caption = caption.replace(/<[a-zA-Z0-9]+( [^<>]+)?>/g, function(a){
				return a.replace(/[\r\n\t]+/, ' ');
			});

			caption = caption.replace(/\s*\n\s*/g, '<br />');
		}
<?php } ?>

		cls = caption ? '' : ' class="'+t.align+'"';

		html = '<img alt="'+alt+'" src="'+f.src.value+'"'+cls+' width="'+t.width+'" height="'+t.height+'" />';

		if ( f.url.value ) {
			url = f.url.value.replace(/'/g, '&#039;').replace(/"/g, '&quot;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
			html = '<a href="'+url+'">'+html+'</a>';
		}

		if ( caption )
			html = '[caption id="" align="'+t.align+'" width="'+t.width+'"]'+html+caption+'[/caption]';

		var win = window.dialogArguments || opener || parent || top;
		win.send_to_editor(html);
		return false;
	},

	resetImageData : function() {
		var t = addExtImage;

		t.width = t.height = '';
		document.getElementById('go_button').style.color = '#bbb';
		if ( ! document.forms[0].src.value )
			document.getElementById('status_img').innerHTML = '';
		else document.getElementById('status_img').innerHTML = '<img src="<?php echo esc_url( admin_url( 'images/no.png' ) ); ?>" alt="" />';
	},

	updateImageData : function() {
		var t = addExtImage;

		t.width = t.preloadImg.width;
		t.height = t.preloadImg.height;
		document.getElementById('go_button').style.color = '#333';
		document.getElementById('status_img').innerHTML = '<img src="<?php echo esc_url( admin_url( 'images/yes.png' ) ); ?>" alt="" />';
	},

	getImageData : function() {
		if ( jQuery('table.describe').hasClass('not-image') )
			return;

		var t = addExtImage, src = document.forms[0].src.value;

		if ( ! src ) {
			t.resetImageData();
			return false;
		}

		document.getElementById('status_img').innerHTML = '<img src="<?php echo esc_url( admin_url( 'images/spinner-2x.gif' ) ); ?>" alt="" width="16" height="16" />';
		t.preloadImg = new Image();
		t.preloadImg.onload = t.updateImageData;
		t.preloadImg.onerror = t.resetImageData;
		t.preloadImg.src = src;
	}
};

jQuery(document).ready( function($) {
	$('.media-types input').click( function() {
		$('table.describe').toggleClass('not-image', $('#not-image').prop('checked') );
	});
});
</script>

<div id="media-items">
<div class="media-item media-blank">
<?php
/**
 * Filters the insert media from URL form HTML.
 *
 * @since WP-3.3.0
 *
 * @param string $form_html The insert from URL form HTML.
 */
echo apply_filters( 'type_url_form_media', wp_media_insert_url_form( $type ) );
?>
</div>
</div>
</form>
<?php
}