...
Classes
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derived
...
from
...
the
...
target
...
class
...
"inherit"
...
all
...
mixins
...
from
...
the
...
target
...
class.
...
In
...
section
...
...
...
...
...
...
...
...
...
we
...
will
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make
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extensive
...
use
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of
...
a
...
Parrot
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class.
...
Many
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types
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of
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parrots
...
exist
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– the
...
clever
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grey
...
parrot,
...
the
...
colorful
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macaw,
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the
...
red
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(marxistic-leninistic?)
...
Cuban
...
parrot.
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The
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list
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in
...
...
goes
...
on
...
and
...
on.
...
Assuming
...
we
...
have
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a
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parrot
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hierarchy
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with
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Parrot
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as
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base
...
class,
...
we
...
can
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mix
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in
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a
...
CircusMixin
...
to
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teach
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parrots
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how
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to
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ride
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the
...
unicycle:
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| Code Block |
|---|
public class Parrot
{
public virtual void Fly ()
{
Console.WriteLine ("Flapflap...");
}
public virtual void Whistle ()
{
Console.WriteLine ("<river kwai march here>");
}
public virtual void Say (string s)
{
Console.WriteLine ("\"{0}\"", s);
}
}
public class GreyParrot : Parrot
{
public virtual void DestroyFurniture ()
{
Console.WriteLine ("Destroying furniture...");
}
}
public class Macaw : Parrot
{
public virtual void CrackNut ()
{
Console.WriteLine ("Cracking nut...");
}
}
public interface ICircusMixin
{
void RideUniCycle ();
}
[Extends (typeof (Parrot))]
public class CircusMixin : ICircusMixin
{
public void RideUniCycle ()
{
Console.WriteLine ("I'm so amazing! I'm riding a unicycle!");
}
}
{code}
Mixing the {{CircusMixin}} to parrot will mix it to the sub-classes {{GreyParrot}} and {{Macaw}} automatically. Not only the {{Parrot}}, also the {{GreyParrot}} and the {{Macaw}} acquire unicycle-skills:
{code} |
Mixing the CircusMixin to parrot will mix it to the sub-classes GreyParrot and Macaw automatically. Not only the Parrot, also the GreyParrot and the Macaw acquire unicycle-skills:
| Code Block |
|---|
// Don't forget to touch the API in the library
FrameworkVersion.RetrieveFromType (typeof (IMixinTarget));
var myCircusParrot = ObjectFactory.Create<Parrot> (ParamList.Empty);
Console.WriteLine ("Parrot:");
myCircusParrot.Whistle (); // do as parrots do
((ICircusMixin) myCircusParrot).RideUniCycle (); // show off what you have learned
Console.WriteLine ();
Console.WriteLine ("GreyParrot:");
var myCircusGreyParrot = ObjectFactory.Create<GreyParrot> (ParamList.Empty);
myCircusGreyParrot.DestroyFurniture (); // grey parrots LOVE destruction
((ICircusMixin) myCircusGreyParrot).RideUniCycle (); // show off what you have learned from your ancestor
Console.WriteLine ();
Console.WriteLine ("Macaw:");
var myCircusMacaw = ObjectFactory.Create<Macaw> (ParamList.Empty);
myCircusMacaw.CrackNut (); // for a macaw, a nut is like a zip-loc; keep hands and feet clear!
((ICircusMixin) myCircusMacaw).RideUniCycle (); // show off what you have learned from your ancestor
Console.WriteLine ();
{code}
|
We
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have
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used
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the
...
Extends
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attribute
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for
...
mixing
...
here.
...
Again,
...
it
...
does
...
not
...
matter
...
whether
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you
...
attribute
...
the
...
mixin
...
class
...
with
...
Extends
...
or
...
the
...
target
...
class
...
with
...
Uses – mixing is inheritable up the class hierarchy.
Sample code
The sample code for this example is in https://svn.re-motion.org/svn/Remotion-Contrib/Samples/Mixin/WikiSamples/trunk/WikiSamples.ParrotSubclasses/Program.cs
...
See also
You can exclude arbitrary subclasses from being mixed. This is an advanced topic and discussed in section advanced re-motion mixins -- removing items, scoping of mixin configurations.