WordPress at a glance
function is not described

WP_Customize_Upload_Control::to_json() public WP 3.4.0

Refresh the parameters passed to the JavaScript via JSON.

{} It's a method of the class: WP_Customize_Upload_Control{}

No Hooks.

Return

null. Nothing.

Usage

$WP_Customize_Upload_Control = new WP_Customize_Upload_Control();
$WP_Customize_Upload_Control->to_json();

Changelog

Since 3.4.0 Introduced.

Code of WP_Customize_Upload_Control::to_json() WP 5.7.2

<?php
public function to_json() {
	parent::to_json();

	$value = $this->value();
	if ( $value ) {
		// Get the attachment model for the existing file.
		$attachment_id = attachment_url_to_postid( $value );
		if ( $attachment_id ) {
			$this->json['attachment'] = wp_prepare_attachment_for_js( $attachment_id );
		}
	}
}