README.md

Virtual Members

"Virtual Member" is a powerful feature of Berry.

Here it should be shown:

• how to use virtual members ?
• how can you use them in practice?

In a nutshell

Let us define a simple class named Test

class Test
   var name
end

and do some assignments.

var test=Test()
test.name='mike'

test.age=55 # !! this will cause an exception, because the member is unkown

Now we do the same with DynClass. This class uses the 'virtual members'. Check also the Berry Documentation.

var test=DynClass()
test.name='mike'
test.age=55
test.description='a tired man'

As we can see, the members are added at runtime. No error is rised.

What can this be used for

We use now function 'toJson() and get a the json-representation of the object instance.

var ss = test.toJson() # '{"age":55,"description":"a tired man","name":"mike"}'
print(ss)

But it works also vice versa.

Let us add the new member 'carCount' in the json-string and let us load this in a new DynClass instance.

var test2=DynClass()
var ss = '{"age":55,"description":"a tired man","name":"mike", "carCount":3}'
test2.loadJson(ss)

print ("carcount:",str(test2.carCount))
print ("age:",str(test2.age))
print ("name:",test2.name)
print ("description:",test2.description)

All members of the json-string exists also as member in the DynClass-instance 'test2'.

The result: Dynclass can be used as a JSON object mapper.

return

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