url to criteria

Filtering.php

<?php
/**
 * Date: 02.03.2018
 * Time: 0:16
 */

use Doctrine\Common\Collections\Criteria;
use Doctrine\Common\Collections\Expr\CompositeExpression;
use Doctrine\Common\Collections\Expr\Expression;
use Doctrine\Common\Collections\ExpressionBuilder;
use Symfony\Component\HttpFoundation\Request;

class Filtering {
	/**
	 * @var Request
	 */
	private $request;
	private $result;
	/**
	 * @var array
	 */
	private $allowedFields;
	
	/**
	 * Filtering constructor.
	 *
	 * @param Request $request
	 * @param array   $allowedFields
	 */
	public function __construct( Request $request, array $allowedFields ) {
		$this->request       = $request;
		$this->allowedFields = $allowedFields;
	}
	
	public function __toString() {
		if ( empty( $this->result ) ) {
			$this->parse();
		}
		return empty( $this->result ) ? "" : http_build_query( $this->result );
	}
	
	/**
	 * @return Expression
	 */
	public function toExpression() {
		$this->parse();
		
		$builder     = Criteria::expr();
		$expressions = [];
		foreach ( $this->result as $name => $value ) {
			$parsed = self::parseFilterValue( $builder, $name, $value );
			if ( null != $parsed ) {
				$expressions[] = $parsed;
			}
		}
		return empty( $expressions ) ? null : new CompositeExpression( CompositeExpression::TYPE_AND, $expressions );
	}
	
	/**
	 * @param ExpressionBuilder $builder
	 * @param string            $field
	 * @param string            $value
	 *
	 * @return  Expression
	 */
	private function parseFilterValue( ExpressionBuilder $builder, $field = "", $value = "" ) {
		$valueIsSingle = strpos( $value, "," ) === false;
		$hasOperand    = strpos( $value, ":" ) !== false;
		if ( ! $hasOperand ) {
			return $valueIsSingle ? $builder->eq( $field, $value ) : $builder->in( $field, explode( ",", $value ) );
		}
		
		$exploded = \explode( ":", $value, 2 );
		
		$operand = strtolower( trim( (string) $exploded[ 0 ] ) );
		$value   = trim( $exploded[ 1 ] );
		
		if ( empty( $operand ) || $operand == "in" || $operand == "eq" ) {
			return $valueIsSingle ? $builder->eq( $field, $value ) : $builder->in( $field, explode( ",", $value ) );
		}
		switch ( $operand ) {
			case "like":
				return $builder->contains( $field, $value );
				break;
			case "lt":
				return $builder->lt( $field, $value );
				break;
			case "gt":
				return $builder->gt( $field, $value );
				break;
			case "lte":
				return $builder->lte( $field, $value );
				break;
			case "gte":
				return $builder->gte( $field, $value );
				break;
			default :
				return null;
		}
	}
	
	private function parse() {
		$filter = [];
		foreach ( $this->request->query->all() as $name => $value ) {
			if ( ! in_array( $name, $this->allowedFields ) || empty( $name ) || empty( $value ) ) {
				continue;
			}
			$filter[ $name ] = $value;
		}
		
		$this->result = $filter;
	}
}