dandjo/object-adapter

Provides adapters for target objects with easy property access via magic getter and setter.

7.0.1 2023-01-19 11:08 UTC

Requires

• php: >=8.0
• ext-json: *

MIT

• Daniel Pernold

• adapter
• object
• getter
• setter

README

Provides some base classes for adapting target objects with annotated property access.

Installation

composer require dandjo/object-adapter

Purpose

Its purpose is to make life easier when working with complex objects behind template engines like Twig. It offers some syntax sugar like writing methods with annotations and accessing the return value via the annotated property name on the adapter. The same applies to setters. It also offers a generic get method for nested data structures using a dotted notation. For this to work, each link in the chain must be an instance of ObjectAdapter or an accessible property.

Usage

To provide a property for your adapter, you have to annotate an appropriate method with either @property\getter property_name or @property\setter property_name. A setter method must take a parameter with the value the property should be set to. The name of the method can be chosen arbitrarily. However, the annotation is important. If there is no getter or setter, the adapter acts transparently on its target object.

Examples

Imagine you have an object with some properties, our target object. When using the ObjectAdapter base class directly, all properties are transparent by default.

$targetObject = new \stdClass();
$targetObject->foo = 'bar';

$myAdapter = new \Dandjo\ObjectAdapter\ObjectAdapter($targetObject);
echo $myAdapter->foo;  // 'bar'

We inherit from the ObjectAdapter and create a getter for the foo property on our target object. With the annotation, the adapter offers a property called myFoo.

class MyAdapter extends \Dandjo\ObjectAdapter\ObjectAdapter {
    
    /**
     * @property\getter myFoo
     */
    public function getMyFoo(): string
    {
        return $this->targetObject->foo;
    }
    
}

$targetObject = new \stdClass();
$targetObject->foo = 'bar';

$myAdapter = new MyAdapter($targetObject);
echo $myAdapter->myFoo;  // 'bar'
echo $targetObject->foo;  // 'bar'

Here's an example with a setter.

class MyAdapter extends \Dandjo\ObjectAdapter\ObjectAdapter {
    
    /**
     * @property\setter myFoo
     */
    public function setMyFoo($value): \Dandjo\ObjectAdapter\ObjectAdapter
    {
        $this->targetObject->foo = $value;
    }
    
}

$targetObject = new \stdClass();
$targetObject->foo = 'bar';

$myAdapter = new MyAdapter($targetObject);
echo $myAdapter->myFoo;  // 'bar'
$myAdapter->myFoo = 'baz';
echo $myAdapter->myFoo;  // 'baz'
echo $targetObject->foo;  // 'baz'

If you want to use deep object hierarchies, have a look at the following example. Chained calls are safe since every non-existent property will return a NullAdapter.

class MyChildAdapter extends \Dandjo\ObjectAdapter\ObjectAdapter {

    /**
     * @property\getter myFoo
     */
    public function getMyFoo(): string
    {
        return $this->targetObject->foo;
    }

}

class MyAdapter extends \Dandjo\ObjectAdapter\ObjectAdapter {
    
    /**
     * @property\getter myChild
     */
    public function getMyChild(): string
    {   
        return new MyChildAdapter($this->targetObject->child);
    }
    
}

$targetObject = new \stdClass();
$targetObject->child = new \stdClass();
$targetObject->child->foo = 'bar';

$myAdapter = new MyAdapter($targetObject);
echo $myAdapter->myChild->myFoo;  // 'bar'

Each adapter implements the ArrayAccess and Interator Interface, so you can also access or loop annotated properties like follows.

class MyAdapter extends \Dandjo\ObjectAdapter\ObjectAdapter {
    
    /**
     * @property\getter myFoo
     */
    public function getMyFoo(): string
    {
        return $this->targetObject->foo;
    }
    
}

$targetObject = new \stdClass();
$targetObject->foo = 'bar';

$myAdapter = new MyAdapter($targetObject);
echo $myAdapter['foo'];  // 'bar'
echo $myAdapter['myFoo'];  // 'bar'

foreach ($myAdapter as $propertyName => $propertyValue) {
    echo "$propertyName: $propertyValue";  // myFoo: bar
}