Generates an array of key => alias pairs joins from dotted path ready for a Doctrine QueryBuilder

queryBuilderGenerator.php

<?php
/**
 * @param string|array $dottedParts
 * @param string $parent
 * @return array
 */
public function getJoinsFromDottedPath($dottedParts, $parent = 'entity')
{
    if (!is_array($dottedParts)) {
        // Assuming the $dottedParts is a string
        if (!strstr($dottedParts, '.')) {
            // Exiting if this string does not contain any dot
            return array();
        }
        // Converting into array
        $dottedParts = explode('.', $dottedParts);
    }
    $joins = array();
    // Adding the current join
    $joins[$parent.'.'.$dottedParts[0]] = $dottedParts[0];
    if (count($dottedParts) > 2) {
        // There are children
        $parent = array_shift($dottedParts);
        $children = $this->getJoinsFromDottedPath($dottedParts, $parent);
        // They are part of the family
        $joins = array_merge($joins, $children);
    }

    return $joins;
}

queryBuilderGeneratorTest.php

<?php
function testGetJoinsFromDottedPath()
{
    $joins = $this->admin->getJoinsFromDottedPath('site.customer');
    $this->assertCount(1, $joins);
    $this->assertEquals('entity.site', array_keys($joins)[0]);
    $this->assertEquals('site', array_values($joins)[0]);

    $joins = $this->admin->getJoinsFromDottedPath('site.customer.address.city');
    $this->assertCount(3, $joins);
    $this->assertEquals('entity.site', array_keys($joins)[0]);
    $this->assertEquals('site', array_values($joins)[0]);
    $this->assertEquals('site.customer', array_keys($joins)[1]);
    $this->assertEquals('customer', array_values($joins)[1]);
    $this->assertEquals('customer.address', array_keys($joins)[2]);
    $this->assertEquals('address', array_values($joins)[2]);
}