374 lines
9.3 KiB
Markdown
374 lines
9.3 KiB
Markdown
# DeepCopy
|
|
|
|
DeepCopy helps you create deep copies (clones) of your objects. It is designed to handle cycles in the association graph.
|
|
|
|
[](https://packagist.org/packages/myclabs/deep-copy)
|
|
[](https://github.com/myclabs/DeepCopy/actions)
|
|
|
|
## Table of Contents
|
|
|
|
1. [How](#how)
|
|
1. [Why](#why)
|
|
1. [Using simply `clone`](#using-simply-clone)
|
|
1. [Overriding `__clone()`](#overriding-__clone)
|
|
1. [With `DeepCopy`](#with-deepcopy)
|
|
1. [How it works](#how-it-works)
|
|
1. [Going further](#going-further)
|
|
1. [Matchers](#matchers)
|
|
1. [Property name](#property-name)
|
|
1. [Specific property](#specific-property)
|
|
1. [Type](#type)
|
|
1. [Filters](#filters)
|
|
1. [`SetNullFilter`](#setnullfilter-filter)
|
|
1. [`KeepFilter`](#keepfilter-filter)
|
|
1. [`DoctrineCollectionFilter`](#doctrinecollectionfilter-filter)
|
|
1. [`DoctrineEmptyCollectionFilter`](#doctrineemptycollectionfilter-filter)
|
|
1. [`DoctrineProxyFilter`](#doctrineproxyfilter-filter)
|
|
1. [`ReplaceFilter`](#replacefilter-type-filter)
|
|
1. [`ShallowCopyFilter`](#shallowcopyfilter-type-filter)
|
|
1. [Edge cases](#edge-cases)
|
|
1. [Contributing](#contributing)
|
|
1. [Tests](#tests)
|
|
|
|
|
|
## How?
|
|
|
|
Install with Composer:
|
|
|
|
```
|
|
composer require myclabs/deep-copy
|
|
```
|
|
|
|
Use it:
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
|
|
$copier = new DeepCopy();
|
|
$myCopy = $copier->copy($myObject);
|
|
```
|
|
|
|
|
|
## Why?
|
|
|
|
- How do you create copies of your objects?
|
|
|
|
```php
|
|
$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()`](http://www.php.net/manual/en/language.oop5.cloning.php#object.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`
|
|
|
|
|
|
|
|
|
|
### Overriding `__clone()`
|
|
|
|
|
|
|
|
|
|
### With `DeepCopy`
|
|
|
|
|
|
|
|
|
|
## How it works
|
|
|
|
DeepCopy recursively traverses all the object's properties and clones them. To avoid cloning the same object twice it
|
|
keeps a hash map of all instances and thus preserves the object graph.
|
|
|
|
To use it:
|
|
|
|
```php
|
|
use function DeepCopy\deep_copy;
|
|
|
|
$copy = deep_copy($var);
|
|
```
|
|
|
|
Alternatively, you can create your own `DeepCopy` instance to configure it differently for example:
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
|
|
$copier = new DeepCopy(true);
|
|
|
|
$copy = $copier->copy($var);
|
|
```
|
|
|
|
You may want to roll your own deep copy function:
|
|
|
|
```php
|
|
namespace Acme;
|
|
|
|
use DeepCopy\DeepCopy;
|
|
|
|
function deep_copy($var)
|
|
{
|
|
static $copier = null;
|
|
|
|
if (null === $copier) {
|
|
$copier = new DeepCopy(true);
|
|
}
|
|
|
|
return $copier->copy($var);
|
|
}
|
|
```
|
|
|
|
|
|
## Going further
|
|
|
|
You can add filters to customize the copy process.
|
|
|
|
The method to add a filter is `DeepCopy\DeepCopy::addFilter($filter, $matcher)`,
|
|
with `$filter` implementing `DeepCopy\Filter\Filter`
|
|
and `$matcher` implementing `DeepCopy\Matcher\Matcher`.
|
|
|
|
We provide some generic filters and matchers.
|
|
|
|
|
|
### Matchers
|
|
|
|
- `DeepCopy\Matcher` applies on a object attribute.
|
|
- `DeepCopy\TypeMatcher` applies on any element found in graph, including array elements.
|
|
|
|
|
|
#### Property name
|
|
|
|
The `PropertyNameMatcher` will match a property by its name:
|
|
|
|
```php
|
|
use DeepCopy\Matcher\PropertyNameMatcher;
|
|
|
|
// Will apply a filter to any property of any objects named "id"
|
|
$matcher = new PropertyNameMatcher('id');
|
|
```
|
|
|
|
|
|
#### Specific property
|
|
|
|
The `PropertyMatcher` will match a specific property of a specific class:
|
|
|
|
```php
|
|
use DeepCopy\Matcher\PropertyMatcher;
|
|
|
|
// Will apply a filter to the property "id" of any objects of the class "MyClass"
|
|
$matcher = new PropertyMatcher('MyClass', 'id');
|
|
```
|
|
|
|
|
|
#### Type
|
|
|
|
The `TypeMatcher` will match any element by its type (instance of a class or any value that could be parameter of
|
|
[gettype()](http://php.net/manual/en/function.gettype.php) function):
|
|
|
|
```php
|
|
use DeepCopy\TypeMatcher\TypeMatcher;
|
|
|
|
// Will apply a filter to any object that is an instance of Doctrine\Common\Collections\Collection
|
|
$matcher = new TypeMatcher('Doctrine\Common\Collections\Collection');
|
|
```
|
|
|
|
|
|
### Filters
|
|
|
|
- `DeepCopy\Filter` applies a transformation to the object attribute matched by `DeepCopy\Matcher`
|
|
- `DeepCopy\TypeFilter` applies a transformation to any element matched by `DeepCopy\TypeMatcher`
|
|
|
|
|
|
#### `SetNullFilter` (filter)
|
|
|
|
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:
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\Filter\SetNullFilter;
|
|
use DeepCopy\Matcher\PropertyNameMatcher;
|
|
|
|
$object = MyClass::load(123);
|
|
echo $object->id; // 123
|
|
|
|
$copier = new DeepCopy();
|
|
$copier->addFilter(new SetNullFilter(), new PropertyNameMatcher('id'));
|
|
|
|
$copy = $copier->copy($object);
|
|
|
|
echo $copy->id; // null
|
|
```
|
|
|
|
|
|
#### `KeepFilter` (filter)
|
|
|
|
If you want a property to remain untouched (for example, an association to an object):
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\Filter\KeepFilter;
|
|
use DeepCopy\Matcher\PropertyMatcher;
|
|
|
|
$copier = new DeepCopy();
|
|
$copier->addFilter(new KeepFilter(), new PropertyMatcher('MyClass', 'category'));
|
|
|
|
$copy = $copier->copy($object);
|
|
// $copy->category has not been touched
|
|
```
|
|
|
|
|
|
#### `DoctrineCollectionFilter` (filter)
|
|
|
|
If you use Doctrine and want to copy an entity, you will need to use the `DoctrineCollectionFilter`:
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\Filter\Doctrine\DoctrineCollectionFilter;
|
|
use DeepCopy\Matcher\PropertyTypeMatcher;
|
|
|
|
$copier = new DeepCopy();
|
|
$copier->addFilter(new DoctrineCollectionFilter(), new PropertyTypeMatcher('Doctrine\Common\Collections\Collection'));
|
|
|
|
$copy = $copier->copy($object);
|
|
```
|
|
|
|
|
|
#### `DoctrineEmptyCollectionFilter` (filter)
|
|
|
|
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`
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\Filter\Doctrine\DoctrineEmptyCollectionFilter;
|
|
use DeepCopy\Matcher\PropertyMatcher;
|
|
|
|
$copier = new DeepCopy();
|
|
$copier->addFilter(new DoctrineEmptyCollectionFilter(), new PropertyMatcher('MyClass', 'myProperty'));
|
|
|
|
$copy = $copier->copy($object);
|
|
|
|
// $copy->myProperty will return an empty collection
|
|
```
|
|
|
|
|
|
#### `DoctrineProxyFilter` (filter)
|
|
|
|
If you use Doctrine and use cloning on lazy loaded entities, you might encounter errors mentioning missing fields on a
|
|
Doctrine proxy class (...\\\_\_CG\_\_\Proxy).
|
|
You can use the `DoctrineProxyFilter` to load the actual entity behind the Doctrine proxy class.
|
|
**Make sure, though, to put this as one of your very first filters in the filter chain so that the entity is loaded
|
|
before other filters are applied!**
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\Filter\Doctrine\DoctrineProxyFilter;
|
|
use DeepCopy\Matcher\Doctrine\DoctrineProxyMatcher;
|
|
|
|
$copier = new DeepCopy();
|
|
$copier->addFilter(new DoctrineProxyFilter(), new DoctrineProxyMatcher());
|
|
|
|
$copy = $copier->copy($object);
|
|
|
|
// $copy should now contain a clone of all entities, including those that were not yet fully loaded.
|
|
```
|
|
|
|
|
|
#### `ReplaceFilter` (type filter)
|
|
|
|
1. If you want to replace the value of a property:
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\Filter\ReplaceFilter;
|
|
use DeepCopy\Matcher\PropertyMatcher;
|
|
|
|
$copier = new DeepCopy();
|
|
$callback = function ($currentValue) {
|
|
return $currentValue . ' (copy)'
|
|
};
|
|
$copier->addFilter(new ReplaceFilter($callback), new PropertyMatcher('MyClass', 'title'));
|
|
|
|
$copy = $copier->copy($object);
|
|
|
|
// $copy->title will contain the data returned by the callback, e.g. 'The title (copy)'
|
|
```
|
|
|
|
2. If you want to replace whole element:
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\TypeFilter\ReplaceFilter;
|
|
use DeepCopy\TypeMatcher\TypeMatcher;
|
|
|
|
$copier = new DeepCopy();
|
|
$callback = function (MyClass $myClass) {
|
|
return get_class($myClass);
|
|
};
|
|
$copier->addTypeFilter(new ReplaceFilter($callback), new TypeMatcher('MyClass'));
|
|
|
|
$copy = $copier->copy([new MyClass, 'some string', new MyClass]);
|
|
|
|
// $copy will contain ['MyClass', 'some string', 'MyClass']
|
|
```
|
|
|
|
|
|
The `$callback` parameter of the `ReplaceFilter` constructor accepts any PHP callable.
|
|
|
|
|
|
#### `ShallowCopyFilter` (type filter)
|
|
|
|
Stop *DeepCopy* from recursively copying element, using standard `clone` instead:
|
|
|
|
```php
|
|
use DeepCopy\DeepCopy;
|
|
use DeepCopy\TypeFilter\ShallowCopyFilter;
|
|
use DeepCopy\TypeMatcher\TypeMatcher;
|
|
use Mockery as m;
|
|
|
|
$this->deepCopy = new DeepCopy();
|
|
$this->deepCopy->addTypeFilter(
|
|
new ShallowCopyFilter,
|
|
new TypeMatcher(m\MockInterface::class)
|
|
);
|
|
|
|
$myServiceWithMocks = new MyService(m::mock(MyDependency1::class), m::mock(MyDependency2::class));
|
|
// All mocks will be just cloned, not deep copied
|
|
```
|
|
|
|
|
|
## Edge cases
|
|
|
|
The following structures cannot be deep-copied with PHP Reflection. As a result they are shallow cloned and filters are
|
|
not applied. There is two ways for you to handle them:
|
|
|
|
- Implement your own `__clone()` method
|
|
- Use a filter with a type matcher
|
|
|
|
|
|
## Contributing
|
|
|
|
DeepCopy is distributed under the MIT license.
|
|
|
|
|
|
### Tests
|
|
|
|
Running the tests is simple:
|
|
|
|
```php
|
|
vendor/bin/phpunit
|
|
```
|
|
|
|
### Support
|
|
|
|
Get professional support via [the Tidelift Subscription](https://tidelift.com/subscription/pkg/packagist-myclabs-deep-copy?utm_source=packagist-myclabs-deep-copy&utm_medium=referral&utm_campaign=readme).
|