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Method not found for child class based on a class from another model [message #1861333]

Fri, 06 October 2023 11:56

Alexander Zemtsov

Messages: 2
Registered: October 2023

Junior Member

Hello everyone!

Let me describe the problem I faced on a little example (Obeo modelling project is attached).

I have two metamodels: A and B. A has a root element and a class BaseClass.
index.php/fa/43555/0/

The B model has a class ChildClass which inherits from BaseClass of model A.
index.php/fa/43556/0/

I defined methods for BaseClass which are a getter and a setter for an attribute name.

operation a!BaseClass getName(): String {
	return self.name;
}

operation a!BaseClass setName(name: String) {
	self.name = name;
}

My sample script runs through all items of my model A and creates new items of ChildClass from the model B.

import "a.eol";

var root = a!Root.all().first();

for (item in root.items) {
	("Processing item " + item.getName()).println();
	
	var newItem = new b!ChildClass();
	newItem.name = item.getName() + "_child";
}

It works fine. But if I replace =name with a setter it fails.

import "a.eol";

var root = a!Root.all().first();

for (item in root.items) {
	("Processing item " + item.getName()).println();
	
	var newItem = new b!ChildClass();
	newItem.setName(item.getName() + "_child");
}

What I expect is successful execution of the script since ChildClass inherits from BaseClass.
What I got is an error:

Method 'setName' not found for: ChildClass [name=null, ]

I suppose, my models load wrong way. Please help me to understand what exactly goes wrong and how to fix it.

Thanks a lot in andvance

Attachment: sampleproject.tar.gz
(Size: 3.59KB, Downloaded 29 times)
Attachment: modelA.png
(Size: 12.57KB, Downloaded 129 times)
Attachment: modelB.png
(Size: 37.33KB, Downloaded 138 times)

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Re: Method not found for child class based on a class from another model [message #1861374 is a reply to message #1861333]

Mon, 09 October 2023 18:02

Dimitris Kolovos

Messages: 2165
Registered: July 2009
Location: York, UK

Senior Member

Hi Alexander,

operation a!BaseClass setName() { ... } adds an operation setName to elements of type BaseClass that belong to the a model. Therefore trying to call setName on elements that belong to the b model fails as expected.

To be able to call setName on elements from both models a and b you need to define it in the context of an alias (e.g. operation x!BaseClass setName() { ... } and then assign the x alias to both models a and b in your run configuration.

Does this answer your question?

Thanks,
Dimitris

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Re: Method not found for child class based on a class from another model [message #1861382 is a reply to message #1861374]

Tue, 10 October 2023 06:39

Alexander Zemtsov

Messages: 2
Registered: October 2023

Junior Member

Hello Dimitris,

Thank you for your answer. You have just confirmed my hunch about that.
Usually, I use metamodels loaded from a plugin installed in Obeo. And the scenario I described in my question runs ok. That is what confused me.
I updated my scripts and now it works fine regardless of how metamodels loaded.

Thank you again!

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