functions.php

function is_streamer_live( $channel, $client_id ) {	
	// Get current status
	$url = 'https://api.twitch.tv/kraken/streams/' . esc_html( trim( $channel, '/' ) ) . '?client_id=' . esc_html( $client_id );
	$response = wp_remote_get( $url );

	if ( ! is_wp_error( $response ) && $response['response']['code'] === 200 ) {
		$body = json_decode( wp_remote_retrieve_body( $response ) );

		if ( empty( $body->stream ) ) {
			return false;
		} else {
			return true;
		}
	}
	
	return false;
}