builder1.php

<?php

class Director
{
    public function build(Builder $builder): Vehicle
    {
        $builder->createVehicle();
        $builder->addDoors();
        $builder->addEngine();
        $builder->addWheel();

        return $builder->getVehicle();
    }
}

interface Builder
{
    public function createVehicle();

    public function addWheel();

    public function addEngine();

    public function addDoors();

    public function getVehicle(): Vehicle;
}


class TruckBuilder implements Builder
{
    private Truck $truck;

    public function addDoors()
    {
        $this->truck->setPart('rightDoor', new Door());
        $this->truck->setPart('leftDoor', new Door());
    }

    public function addEngine()
    {
        $this->truck->setPart('truckEngine', new Engine());
    }

    public function addWheel()
    {
        $this->truck->setPart('wheel1', new Wheel());
        $this->truck->setPart('wheel2', new Wheel());
        $this->truck->setPart('wheel3', new Wheel());
        $this->truck->setPart('wheel4', new Wheel());
        $this->truck->setPart('wheel5', new Wheel());
        $this->truck->setPart('wheel6', new Wheel());
    }

    public function createVehicle()
    {
        $this->truck = new Truck();
    }

    public function getVehicle(): Vehicle
    {
        return $this->truck;
    }
}


class CarBuilder implements Builder
{
    private Car $car;

    public function addDoors()
    {
        $this->car->setPart('rightDoor', new Door());
        $this->car->setPart('leftDoor', new Door());
        $this->car->setPart('trunkLid', new Door());
    }

    public function addEngine()
    {
        $this->car->setPart('engine', new Engine());
    }

    public function addWheel()
    {
        $this->car->setPart('wheelLF', new Wheel());
        $this->car->setPart('wheelRF', new Wheel());
        $this->car->setPart('wheelLR', new Wheel());
        $this->car->setPart('wheelRR', new Wheel());
    }

    public function createVehicle()
    {
        $this->car = new Car();
    }

    public function getVehicle(): Vehicle
    {
        return $this->car;
    }
}

abstract class Vehicle
{
    /**
     * @var object[]
     */
    private array $data = [];

    public function setPart(string $key, object $value)
    {
        $this->data[$key] = $value;
    }
}

class Truck extends Vehicle
{
}


class Engine
{
}

class Wheel
{
}

class Door
{
}

// USAGE
$truckBuilder = new TruckBuilder();
$newVehicle = (new Director())->build($truckBuilder);

$carBuilder = new CarBuilder();
$newVehicle = (new Director())->build($carBuilder);

builder2.php

<?php

/**
 * The Builder interface declares a set of methods to assemble an SQL query.
 *
 * All of the construction steps are returning the current builder object to
 * allow chaining: $builder->select(...)->where(...)
 */
interface SQLQueryBuilder
{
    public function select(string $table, array $fields): SQLQueryBuilder;

    public function where(string $field, string $value, string $operator = '='): SQLQueryBuilder;

    public function limit(int $start, int $offset): SQLQueryBuilder;

    // +100 other SQL syntax methods...

    public function getSQL(): string;
}

/**
 * Each Concrete Builder corresponds to a specific SQL dialect and may implement
 * the builder steps a little bit differently from the others.
 *
 * This Concrete Builder can build SQL queries compatible with MySQL.
 */
class MysqlQueryBuilder implements SQLQueryBuilder
{
    protected $query;

    protected function reset(): void
    {
        $this->query = new \stdClass;
    }

    /**
     * Build a base SELECT query.
     */
    public function select(string $table, array $fields): SQLQueryBuilder
    {
        $this->reset();
        $this->query->base = "SELECT " . implode(", ", $fields) . " FROM " . $table;
        $this->query->type = 'select';

        return $this;
    }

    /**
     * Add a WHERE condition.
     */
    public function where(string $field, string $value, string $operator = '='): SQLQueryBuilder
    {
        if (!in_array($this->query->type, ['select', 'update', 'delete'])) {
            throw new \Exception("WHERE can only be added to SELECT, UPDATE OR DELETE");
        }
        $this->query->where[] = "$field $operator '$value'";

        return $this;
    }

    /**
     * Add a LIMIT constraint.
     */
    public function limit(int $start, int $offset): SQLQueryBuilder
    {
        if (!in_array($this->query->type, ['select'])) {
            throw new \Exception("LIMIT can only be added to SELECT");
        }
        $this->query->limit = " LIMIT " . $start . ", " . $offset;

        return $this;
    }

    /**
     * Get the final query string.
     */
    public function getSQL(): string
    {
        $query = $this->query;
        $sql = $query->base;
        if (!empty($query->where)) {
            $sql .= " WHERE " . implode(' AND ', $query->where);
        }
        if (isset($query->limit)) {
            $sql .= $query->limit;
        }
        $sql .= ";";
        return $sql;
    }
}

/**
 * This Concrete Builder is compatible with PostgreSQL. While Postgres is very
 * similar to Mysql, it still has several differences. To reuse the common code,
 * we extend it from the MySQL builder, while overriding some of the building
 * steps.
 */
class PostgresQueryBuilder extends MysqlQueryBuilder
{
    /**
     * Among other things, PostgreSQL has slightly different LIMIT syntax.
     */
    public function limit(int $start, int $offset): SQLQueryBuilder
    {
        parent::limit($start, $offset);

        $this->query->limit = " LIMIT " . $start . " OFFSET " . $offset;

        return $this;
    }

    // + tons of other overrides...
}


/**
 * Note that the client code uses the builder object directly. A designated
 * Director class is not necessary in this case, because the client code needs
 * different queries almost every time, so the sequence of the construction
 * steps cannot be easily reused.
 *
 * Since all our query builders create products of the same type (which is a
 * string), we can interact with all builders using their common interface.
 * Later, if we implement a new Builder class, we will be able to pass its
 * instance to the existing client code without breaking it thanks to the
 * SQLQueryBuilder interface.
 */
function clientCode(SQLQueryBuilder $queryBuilder)
{
    // ...

    $query = $queryBuilder
        ->select("users", ["name", "email", "password"])
        ->where("age", 18, ">")
        ->where("age", 30, "<")
        ->limit(10, 20)
        ->getSQL();

    echo $query;

    // ...
}


/**
 * The application selects the proper query builder type depending on a current
 * configuration or the environment settings.
 */
// if ($_ENV['database_type'] == 'postgres') {
//     $builder = new PostgresQueryBuilder(); } else {
//     $builder = new MysqlQueryBuilder; }
//
// clientCode($builder);


echo "Testing MySQL query builder:\n";
clientCode(new MysqlQueryBuilder);

echo "\n\n";

echo "Testing PostgresSQL query builder:\n";
clientCode(new PostgresQueryBuilder);
 Output.txt: Execution result
Testing MySQL query builder:
SELECT name, email, password FROM users WHERE age > '18' AND age < '30' LIMIT 10, 20;

Testing PostgresSQL query builder:
SELECT name, email, password FROM users WHERE age > '18' AND age < '30' LIMIT 10 OFFSET 20;

builder3.php

<?php

class Director {

    public function buildDevice (DeviceBuilder $builder) {

        $builder->createDevice();
        $builder->setHardware();
        $builder->setSoftware();
        $builder->setupSLA();

        return $builder->getDevice();
    }
}


interface DeviceBuilder {

    public function setHardware ();

    public function setSoftware ();

    public function setupSLA ();

    public function createDevice ();

    public function getDevice ();

}

class InteractiveMirror {

    public $hardware = [];
    public $software = '';
    public $sla = '';

}

class InteractiveMirrorBuilder implements DeviceBuilder {

    private $device;

    public function setHardware () {
        $components = ['display', 'glass', 'PC', 'frame'];

        foreach ($components as $component) {
            $this->device->hardware[] = $component;
        }
    }

    public function setSoftware () {
        $this->device->software = 'Mirror software';
    }

    public function setupSLA () {
        $this->device->sla = 'Mirror SLA V2';
    }

    public function createDevice () {
        $this->device = new InteractiveMirror();
    }

    public function getDevice () {
        return $this->device;
    }
}

$mirrorBuilder = new InteractiveMirrorBuilder();
$director = new Director();
$mirror = $director->buildDevice($mirrorBuilder);

var_dump($mirror);

builder4.php

<?php

/**
 * An extremely basic class for creating people objects
 */
class Person
{
    public $employed;
 
    public $gender;
 
    const GENDER_MALE   = "Male";
 
    const GENDER_FEMALE = "Female";
 
}
 
/**
 * All people builder should implement this interface
 */
interface PersonBuilderInterface
{
    public function setGender();
    public function setEmployed();
    public function getResult();
}
 
/**
 * builder to create an employed male
 */
class EmployedMaleBuilder implements PersonBuilderInterface
{
    private $person;
 
    public function __construct()
    {
        $this->person = new Person();
    }
 
    public function setGender()
    {
        $this->person->gender = Person::GENDER_MALE;
    }
 
    public function setEmployed()
    {
        $this->person->employed = true;
    }
 
    public function getResult()
    {
        return $this->person;
    }
}
 
/**
 * builder to create an unemployed male
 */
class UnemployedMaleBuilder implements PersonBuilderInterface
{
    private $person;
 
    public function __construct()
    {
        $this->person = new Person();
    }
 
 
    public function setGender()
    {
        $this->person->gender = Person::GENDER_MALE;
    }
 
    public function setEmployed()
    {
        $this->person->employed = false;
    }
 
    public function getResult()
    {
        return $this->person;
    }
}
 
/**
 * builder to create an employed female
 */
class EmployedFemaleBuilder implements PersonBuilderInterface
{
    private $person;
 
    public function __construct()
    {
        $this->person = new Person();
    }
 
    public function setGender()
    {
        $this->person->gender = Person::GENDER_FEMALE;
    }
 
    public function setEmployed()
    {
        $this->person->employed = true;
    }
 
    public function getResult()
    {
        return $this->person;
    }
}
 
/**
 * builder to create an unemployed female
 */
class UnemployedFemaleBuilder implements PersonBuilderInterface
{
    private $person;
 
    public function __construct()
    {
        $this->person = new Person();
    }
 
    public function setGender()
    {
        $this->person->gender = Person::GENDER_FEMALE;
    }
 
    public function setEmployed()
    {
        $this->person->employed = false;
    }
 
    public function getResult()
    {
        return $this->person;
    }
}
 
/**
 * The director class is part of the builder patter, the build method should be passed a builder.
 * The build method should than call all of the builder methods and return a Person object
 */
class PersonDirector
{
    public function build(PersonBuilderInterface $builder)
    {
        $builder->setGender();
        $builder->setEmployed();
 
        return $builder->getResult();
    }
}
 
$director                = new PersonDirector();
$employedMaleBuilder     = new EmployedMaleBuilder();
$unemployedMaleBuilder   = new UnemployedMaleBuilder();
$employedFemaleBuilder   = new EmployedFemaleBuilder();
$unemployedFemaleBuilder = new UnemployedFemaleBuilder();
 
/**
 * object(Person)#3 (2) {
 * (
 *   ["employed"] => bool(true)
 *   ["gender"] => string(4) "Male"
 * )
 */
$employedMale     = $director->build($employedMaleBuilder);
 
/**
 * object(Person)#5 (2) {
 * (
 *   ["employed"] => bool(false)
 *   ["gender"] => string(4) "Male"
 * )
 */
$unemployedMale   = $director->build($unemployedMaleBuilder);
 
/**
 * object(Person)#7 (2) {
 * (
 *   ["employed"] => bool(true)
 *   ["gender"] => string(4) "Female"
 * )
 */
$employedFemale   = $director->build($employedFemaleBuilder);
 
/**
 * object(Person)#11 (2) {
 * (
 *   ["employed"] => bool(false)
 *   ["gender"] => string(4) "Female"
 * )
 */
$unemployedFemale = $director->build($unemployedFemaleBuilder);

pic.md