wp-includes/customize/class-wp-customize-upload-control.php:53Refresh the parameters passed to the JavaScript via JSON.
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 ); } } }Introduced in 3.4.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/customize/class-wp-customize-upload-control.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.