The an advance xml builder class

xml_builder.php

<?php


class Xmlbuilder
{

    private SimpleXMLElement $element;


    public function __construct(SimpleXMLElement $simpleXMLElement = new SimpleXMLElement('<root/>'))
    {
        $this->element = $simpleXMLElement;
    }

    public function add(string $key, string $value): self
    {
        $this->element->addChild($key, $value);
        return $this;
    }

    public function addNested(string $key, array $values): self
    {
        $parentElement = $this->element->addChild($key);
        foreach ($values as $keyName => $value) {
            if (is_array($value)) {
                $this->addNested($keyName, $value);
                continue;
            }
            $parentElement?->addChild($keyName, $value);
        }
        return $this;
    }

    public function __toString(): string
    {
        return $this->element->asXML();
    }

    public function child(string $parentElement, Closure $closure): self
    {
        $closure(new self($this->element->addChild($parentElement)));
        return $this;
    }

}


$fluid = new Xmlbuilder();
$fluid
    ->add('a', '1')
    ->add('b', '2')
    ->add('c', '3')
    ->addNested('nested', ['foo' => 'bar'])
    ->child('detail', function (Xmlbuilder $fluid) {
        $fluid
            ->add('city', 'madrid')
            ->child('region', function (Xmlbuilder $fluid) {
                $fluid->add('country', 'spain');
            });

    })
    ->add('e', 5);


echo $fluid;

the output

<?xml version="1.0"?>
<root>
    <a>1</a>
    <b>2</b>
    <c>3</c>
    <nested>
        <foo>bar</foo>
    </nested>
    <detail>
        <city>madrid</city>
        <region>
            <country>spain</country>
        </region>
    </detail>
    <e>5</e>
</root>