Koc / DeepCopy

Create deep copies (clones) of your objects

DeepCopy

DeepCopy helps you create deep copies (clones) of your objects. It is designed to handle cycles in the association graph.

How?

Install with Composer:

{
    "require": {
        "myclabs/deep-copy": "*"
    }
}

Use simply:

$deepCopy = new DeepCopy();
$myCopy = $deepCopy->copy($myObject);

Why?

• How do you create copies of your objects?

$myCopy = clone $myObject;

• How do you create deep copies of your objects (i.e. copying also all the objects referenced in the properties)?

You use __clone() and implement the behavior yourself.

• But how do you handle cycles in the association graph?

Now you're in for a big mess :(

Using simply clone

Overridding __clone()

With DeepCopy

How it works

DeepCopy traverses recursively all your object's properties and clones them.

To avoid cloning the same object twice (and thus, keep you object graph), it keeps a hash-map of all instances.

Going further

You can add filters to customize the copy process.

The method to add a filter is $deepCopy->addFilter($filter, $matcher), with $filter implementing DeepCopy\Filter\Filter and $matcher implementing DeepCopy\Matcher\Matcher.

We provide some generic filters and matchers.

Matchers

Property name

The PropertyNameMatcher will match a property by its name:

$matcher = new PropertyNameMatcher('id');
// will apply a filter to any property of any objects named "id"

Specific property

The PropertyMatcher will match a specific property of a specific class:

$matcher = new PropertyMatcher('MyClass', 'id');
// will apply a filter to the property "id" of any objects of the class "MyClass"

Property type

The PropertyTypeMatcher will match a property by its type (instance of a class):

$matcher = new PropertyTypeMatcher('Doctrine\Common\Collections\Collection');
// will apply a filter to any property that is an instance of Doctrine\Common\Collections\Collection

Filters

SetNullFilter

Let's say for example that you are copying a database record (or a Doctrine entity), so you want the copy not to have any ID:

$myObject = MyClass::load(123);
echo $myObject->id; // 123

$deepCopy = new DeepCopy();
$deepCopy->addFilter(new SetNullFilter(), new PropertyNameMatcher('id'));
$myCopy = $deepCopy->copy($myObject);

echo $myCopy->id; // null

KeepFilter

If you want a property to remain untouched (for example, an association to an object):

$deepCopy = new DeepCopy();
$deepCopy->addFilter(new KeepFilter(), new PropertyMatcher('MyClass', 'category'));
$myCopy = $deepCopy->copy($myObject);

// $myCopy->category has not been touched

DoctrineCollectionFilter

If you use Doctrine and want to copy an entity, you will need to use the DoctrineCollectionFilter:

$deepCopy = new DeepCopy();
$deepCopy->addFilter(new DoctrineCollectionFilter(), new PropertyTypeMatcher('Doctrine\Common\Collections\Collection'));
$myCopy = $deepCopy->copy($myObject);

DoctrineEmptyCollectionFilter

If you use Doctrine and want to copy an entity who contains a Collection that you want to be reset, you can use the DoctrineEmptyCollectionFilter

$deepCopy = new DeepCopy();
$deepCopy->addFilter(new DoctrineEmptyCollectionFilter(), new PropertyMatcher('MyClass', 'myProperty'));
$myCopy = $deepCopy->copy($myObject);

// $myCopy->myProperty will return an empty collection

Contributing

DeepCopy is distributed under the MIT license.

Tests

Running the tests is simple:

phpunit