wiki.techinc.nl/includes/json/FormatJson.php

<?php
/**
 * Simple wrapper for json_econde and json_decode that falls back on Services_JSON class
 */
if ( !defined( 'MEDIAWIKI' ) ) {
	die( 1 );
}

class FormatJson {
	public static function encode( $value, $isHtml = false ) {
		// Some versions of PHP have a broken json_encode, see PHP bug
		// 46944. Test encoding an affected character (U+20000) to
		// avoid this.
		if ( !function_exists( 'json_encode' ) || $isHtml || strtolower( json_encode( "\xf0\xa0\x80\x80" ) ) != '\ud840\udc00' ) {
			$json = new Services_JSON();
			return $json->encode( $value, $isHtml );
		} else {
			return json_encode( $value );
		}
	}

	public static function decode( $value, $assoc = false ) {
		if ( !function_exists( 'json_decode' ) ) {
			$json = new Services_JSON();
			$jsonDec = $json->decode( $value );
			if( $assoc ) {
				$jsonDec = wfObjectToArray( $jsonDec );
			}
			return $jsonDec;
		} else {
			return json_decode( $value, $assoc );
		}
	}
}