Doctrine SQL If Function

IfFunction.php

<?php
namespace Your\PathToBundle\DQL;

use Doctrine\ORM\Query\Lexer;
use Doctrine\ORM\Query\AST\Functions\FunctionNode;
use Doctrine\ORM\Query\Parser;
use Doctrine\ORM\Query\SqlWalker;

/**
 * Created by PhpStorm.
 * User: Edwin Yoyada Pratama
 * Date: 11/24/2016
 * Time: 12:19 PM
 */
class IfFunction extends FunctionNode {
    public $firstStringExpression = null;
    public $secondStringExpression = null;
    public $isTrue = null;
    public $isFalse = null;

    public function parse(Parser $parser)
    {
        $parser->match(Lexer::T_IDENTIFIER);
        $parser->match(Lexer::T_OPEN_PARENTHESIS);
        $this->firstStringExpression  = $parser->SimpleEntityExpression();
        $parser->match(Lexer::T_EQUALS);
        $this->secondStringExpression  = $parser->StringPrimary();
        $parser->match(Lexer::T_COMMA);
        $this->isTrue  = $parser->SimpleArithmeticExpression();
        $parser->match(Lexer::T_COMMA);
        $this->isFalse  = $parser->SimpleArithmeticExpression();
        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
    }

    public function getSql(SqlWalker $sqlWalker)
    {
        return "IF(" . $this->firstStringExpression->dispatch($sqlWalker) . " = " . $this->secondStringExpression->dispatch($sqlWalker) . ", " . $this->isTrue->dispatch($sqlWalker) . ", " . $this->isFalse->dispatch($sqlWalker) . ")";
    }
}

Nice