When using the Decorator pattern, how do you decorate additional functionality in between the concrete...
I'm trying to understand if I am using the Decorator pattern properly, or if another pattern would be better suited for a situation like this:
Without redefining my interface, I am unable to decorate a function because it's parent's definition prevents me from doing so. I'm not sure if my question is clear, so perhaps an example:
interface IFoo
{
public function bar();
}
class ConcreteFoo implements IFoo
{
public function bar()
{
echo "hello world!n";
}
}
abstract class Decorator implements IFoo
{
public function __construct(IFoo $foo)
{
$this->foo = $foo;
}
public function bar()
{
$this->foo->bar();
}
}
class BeautifulDecorator extends Decorator
{
public function bar()
{
// I am unable to insert 'beautiful' between 'hello' and 'world' without redefining the bar() function again
parent::bar();
}
}
For the sake of simplicity, I am essentially unable to print out something like 'hello beautiful world' without actually redefining the bar function to do so.
Is there a way to do so with the Decorator pattern, or is there a different pattern that can be used?
design-patterns decorator
asked Nov 16 '18 at 8:12
kennzorskennzors
107
add a comment |
I'm trying to understand if I am using the Decorator pattern properly, or if another pattern would be better suited for a situation like this:
Without redefining my interface, I am unable to decorate a function because it's parent's definition prevents me from doing so. I'm not sure if my question is clear, so perhaps an example:
interface IFoo
{
public function bar();
}
class ConcreteFoo implements IFoo
{
public function bar()
{
echo "hello world!n";
}
}
abstract class Decorator implements IFoo
{
public function __construct(IFoo $foo)
{
$this->foo = $foo;
}
public function bar()
{
$this->foo->bar();
}
}
class BeautifulDecorator extends Decorator
{
public function bar()
{
// I am unable to insert 'beautiful' between 'hello' and 'world' without redefining the bar() function again
parent::bar();
}
}
For the sake of simplicity, I am essentially unable to print out something like 'hello beautiful world' without actually redefining the bar function to do so.
Is there a way to do so with the Decorator pattern, or is there a different pattern that can be used?
design-patterns decorator
asked Nov 16 '18 at 8:12
kennzorskennzors
107
A decorator "wraps" the decoratee and can add functionality before/after the wrapped methods - to inject functionality you would need to use something like the strategy pattern
– qujck
Nov 16 '18 at 8:44
add a comment |
I'm trying to understand if I am using the Decorator pattern properly, or if another pattern would be better suited for a situation like this:
Without redefining my interface, I am unable to decorate a function because it's parent's definition prevents me from doing so. I'm not sure if my question is clear, so perhaps an example:
interface IFoo
{
public function bar();
}
class ConcreteFoo implements IFoo
{
public function bar()
{
echo "hello world!n";
}
}
abstract class Decorator implements IFoo
{
public function __construct(IFoo $foo)
{
$this->foo = $foo;
}
public function bar()
{
$this->foo->bar();
}
}
class BeautifulDecorator extends Decorator
{
public function bar()
{
// I am unable to insert 'beautiful' between 'hello' and 'world' without redefining the bar() function again
parent::bar();
}
}
For the sake of simplicity, I am essentially unable to print out something like 'hello beautiful world' without actually redefining the bar function to do so.
Is there a way to do so with the Decorator pattern, or is there a different pattern that can be used?
design-patterns decorator
asked Nov 16 '18 at 8:12
kennzorskennzors
107
I'm trying to understand if I am using the Decorator pattern properly, or if another pattern would be better suited for a situation like this:
Without redefining my interface, I am unable to decorate a function because it's parent's definition prevents me from doing so. I'm not sure if my question is clear, so perhaps an example:
interface IFoo
{
public function bar();
}
class ConcreteFoo implements IFoo
{
public function bar()
{
echo "hello world!n";
}
}
abstract class Decorator implements IFoo
{
public function __construct(IFoo $foo)
{
$this->foo = $foo;
}
public function bar()
{
$this->foo->bar();
}
}
class BeautifulDecorator extends Decorator
{
public function bar()
{
// I am unable to insert 'beautiful' between 'hello' and 'world' without redefining the bar() function again
parent::bar();
}
}
For the sake of simplicity, I am essentially unable to print out something like 'hello beautiful world' without actually redefining the bar function to do so.
Is there a way to do so with the Decorator pattern, or is there a different pattern that can be used?
design-patterns decorator
design-patterns decorator
asked Nov 16 '18 at 8:12
kennzorskennzors
107
asked Nov 16 '18 at 8:12
kennzorskennzors
107
asked Nov 16 '18 at 8:12
kennzorskennzors
107
asked Nov 16 '18 at 8:12
kennzorskennzors
107
asked Nov 16 '18 at 8:12
kennzorskennzors
107
107
A decorator "wraps" the decoratee and can add functionality before/after the wrapped methods - to inject functionality you would need to use something like the strategy pattern
– qujck
Nov 16 '18 at 8:44
add a comment |
A decorator "wraps" the decoratee and can add functionality before/after the wrapped methods - to inject functionality you would need to use something like the strategy pattern
– qujck
Nov 16 '18 at 8:44
A decorator "wraps" the decoratee and can add functionality before/after the wrapped methods - to inject functionality you would need to use something like the strategy pattern
– qujck
Nov 16 '18 at 8:44
A decorator "wraps" the decoratee and can add functionality before/after the wrapped methods - to inject functionality you would need to use something like the strategy pattern
– qujck
Nov 16 '18 at 8:44
add a comment |
1 Answer
1
active
oldest
votes
Use Decorator when
you want the object to perform additional operations before and after the execution of a method
extension by subclassing can lead to an explosion of subclasses to support every combination of operations
In your case, you do not want to add any additional operations before or after the bar() but you actually want to replace the algorithm of that method, so this is not the intent of Decorator
And if the class prevents you from changing its algorithm, in your example, there're no ways to ask the object to print anything other than 'hello world!', so that means the behavior is encapsulated into the object and there are no patterns designed to break the encapsulation.
I believe the only solution here is change the ConcreteFoo implementation or just create another concrete class.
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Use Decorator when
you want the object to perform additional operations before and after the execution of a method
extension by subclassing can lead to an explosion of subclasses to support every combination of operations
In your case, you do not want to add any additional operations before or after the bar() but you actually want to replace the algorithm of that method, so this is not the intent of Decorator
And if the class prevents you from changing its algorithm, in your example, there're no ways to ask the object to print anything other than 'hello world!', so that means the behavior is encapsulated into the object and there are no patterns designed to break the encapsulation.
I believe the only solution here is change the ConcreteFoo implementation or just create another concrete class.
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
add a comment |
Use Decorator when
you want the object to perform additional operations before and after the execution of a method
extension by subclassing can lead to an explosion of subclasses to support every combination of operations
In your case, you do not want to add any additional operations before or after the bar() but you actually want to replace the algorithm of that method, so this is not the intent of Decorator
And if the class prevents you from changing its algorithm, in your example, there're no ways to ask the object to print anything other than 'hello world!', so that means the behavior is encapsulated into the object and there are no patterns designed to break the encapsulation.
I believe the only solution here is change the ConcreteFoo implementation or just create another concrete class.
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
add a comment |
Use Decorator when
you want the object to perform additional operations before and after the execution of a method
extension by subclassing can lead to an explosion of subclasses to support every combination of operations
In your case, you do not want to add any additional operations before or after the bar() but you actually want to replace the algorithm of that method, so this is not the intent of Decorator
And if the class prevents you from changing its algorithm, in your example, there're no ways to ask the object to print anything other than 'hello world!', so that means the behavior is encapsulated into the object and there are no patterns designed to break the encapsulation.
I believe the only solution here is change the ConcreteFoo implementation or just create another concrete class.
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
Use Decorator when
you want the object to perform additional operations before and after the execution of a method
extension by subclassing can lead to an explosion of subclasses to support every combination of operations
In your case, you do not want to add any additional operations before or after the bar() but you actually want to replace the algorithm of that method, so this is not the intent of Decorator
And if the class prevents you from changing its algorithm, in your example, there're no ways to ask the object to print anything other than 'hello world!', so that means the behavior is encapsulated into the object and there are no patterns designed to break the encapsulation.
I believe the only solution here is change the ConcreteFoo implementation or just create another concrete class.
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
edited Nov 18 '18 at 18:17
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
answered Nov 18 '18 at 18:09
ndnhuyndnhuy
912
912
add a comment |
add a comment |
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A decorator "wraps" the decoratee and can add functionality before/after the wrapped methods - to inject functionality you would need to use something like the strategy pattern
– qujck
Nov 16 '18 at 8:44