| Conditional mappings [message #1850523] |
Mon, 07 March 2022 15:03  |
 Francesco Bedini
Messages: 32
Registered: March 2018 |
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I'm trying to convert a class of the source metamodel (let's call it S) in different ways, depending on one of the values of its attributes.
If S.attr = true, generate one single element of class D.
If S.attr = false, generate 3 elements of class D, and other objects
(simplified for clarity, in my case the attribute is not a boolean and has 5 possible values)
I thought about duplicating the mapping and using the when {} guard based on that attribute.
mapping S::transformationName() : D when {self.attr = true} {}
// 1: Generating the same output
mapping S::transformationName() : D when {self.attr = false} {}
// 2: Generating a different output
mapping S::transformationName() : d : List(D), e : List(E) when {self.attr = false} {}
Doing that, I get: "Operation 'transformationName' is already defined for type 'S'" in both cases
I have some notes from the past (I don't know from where) that said that theoretically the first mapping which has a "when" guard which results true should be selected for that transformation, is that wrong?
As, in my case, the different mappings would return a different number of elements and additional objects of other types of destination metamodel elements, is that even possible?
- Or should I just create a single mapping with an if condition which returns all possible outputs?
- Have different mappings with different names, and have an if which calls the right method for each element.
Thanks in advance for the support and let me know if you'd like to have a larger minimal working example, if I wasn't clear.
[Updated on: Mon, 07 March 2022 15:07] Report message to a moderator |
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