Upload base64 encoded image to WordPress using FlowMattic

functions.php

<?php
/**
 * Save the base64 encoded image in WP.
 *
 * @param string $title      Image title without extension.
 * @param string $base64_img Base64 encoded image string.
 */
function flowmattic_save_base64_image( $title, $base64_img ) {

	// Upload dir.
	$upload_dir  = wp_upload_dir();
	$upload_path = str_replace( '/', DIRECTORY_SEPARATOR, $upload_dir['path'] ) . DIRECTORY_SEPARATOR;

	$image_parts  = explode( ',', $base64_img );
	$img_part_1   = str_replace( 'data:image/', '', $image_parts[0] );
	$image_decode = base64_decode( $image_parts[1] );

	$mime      = str_replace( ';base64', '', $img_part_1 );
	$file_type = 'image/' . $mime;

	if ( 'svg+xml' === $mime ) {
		$mime = 'svg';
	}

	// Set the file name with image extension.
	$filename = $title . '.' . $mime;

	$hashed_filename = md5( $filename . microtime() ) . '_' . $filename;

	// Save the image in the uploads directory.
	$upload_file = file_put_contents( $upload_path . $filename, $image_decode );

	$attachment = array(
		'post_mime_type' => $file_type,
		'post_title'     => $filename,
		'post_content'   => '',
		'post_status'    => 'inherit',
		'guid'           => $upload_dir['url'] . '/' . $filename,
	);

	// Insert attachment for use in WP.
	$image_id = wp_insert_attachment( $attachment, $upload_dir['path'] . '/' . $filename );

	// Return the image attachment post ID.
	return array(
		'image_id'  => $image_id,
		'image_url' => wp_get_attachment_url( $image_id, 'full' ),
	);
}