nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Runtime Type Information (instanceof)

medini_1025405396

How can I check the runtime type of an object in a script?

The regular 'instanceof' if javascript does not work the way I want because the actual runtime type of medini objects is ...Impl.
I would like to check against the interface (e.g. object instanceof Metamodel.safetygoals.SafetyRequirement).

I already heard about a meod 'isInstacneof' but I could not figure out how to use it.

Does anyone have an example on using 'isInstanceof'?

Greetings

Ralph

Find more posts tagged with

medini

medini legacy

Accepted answers

All comments

medini_1028110424

Hi Ralph, not sure I totally understand but hope this helps?

//var FS_R = Factory.createElement(specific_model, Metamodel.safetygoals.SafetyRequirement);

//FS_R.kind = Metamodel.safetygoals.SafetyReqKind.FUNCTIONAL.instance;

//FS_R.name = "Functional_Safety_Requirement";

medini_1024169437

Hello Ralph,

thanks for opening the discussion on this interesting topic. I checked the scripting guide, and have to admit that its a bit weak on this subject.

@Anthony: I think Ralph is referring to situations as this one:

// check selection
if (selection && selection.length && selection[0] instanceof Metamodel.safetygoals.SafetyGoal) {
	alert("You selected a goal");
}

This is not working because the objects contained in "Metamodel" are the EMF Metaclasses and not the generated Java interfaces. So Metamodel.safetygoals.SafetyGoal is of type EClass and not the generated "SafetyGoal" Java interface.

There are two solutions for this, solution 1 uses the == operator:

// we use the prototype and the == operator 
if (selection && selection.length && selection[0].prototype == Metamodel.safetygoals.SafetyGoal) {
	alert("You selected a goal");
}

This is working if the selected object is a safety goal because the prototype is exactly the EClass of "SafetyGoal". The following will not work though:

// we use the prototype and the == operator 
if (selection && selection.length && selection[0].prototype == Metamodel.safetyModel.Failure) {
	alert("You selected a failure");
}

Failure is an abstract base class for Hazard, Malfunction etc. So the prototype is not exactly the EClass of "Failure" but a sub-class of it (on metamodel level). In these cases the "EClass.isInstance()" method has to be used:

// we use the EClass.isInstance() method 
if (selection && selection.length && Metamodel.safetyModel.Failure.isInstance(selection[0])) {
	alert("You selected a failure");
}

Note that in the later example we do not use the object's prototype.

Happy Scripting

Jan

medini_1025405396

Thanks to both of you for your replies.

Jan, you are right. This is exactly what I was looking for.

Greetings

Ralph

medini_1004298271

I am happy to announce that with the upcoming version 2019 R1 (aka 19.3) the instanceof operator will be available.

Happy Scripting
Jan

medini_1079618480

Hello Jan,

Is there any way to check whether an EMF belongs to an abstract class?

For example, the return is True for all Metamodel.sysml.* like Metamodel.sysml.SysMLPortUsage, Metamodel.sysml.SysMLPart ... and so on.

medini_1024169437

Hi Ka-lib,

the instanceof operator should honor the class hirarchy, at least thats the way how we implemented it so:

var x = <selected part>

x instanceof Metamodel.sysml.SysMLPart => true

x instanceof Metamodel.sysml.SysMLElement => true

x instanceof Metamodel.safetyModel.Failable => true

x instanceof Metamodel.sysml.SysMLBlock => false

should work.

Jan

medini_1079618480

Hello Jan,

instanceof works in a different way I expected.

Given I have 3 selections now.

selection[0] instanceof Metamodel.sysml.SysMLPortUsage => true

selection[1] instanceof Metamodel.sysml.SysMLPart => true

selection[2] instanceof Metamodel.safetyModel.FailureMode => true

What I want is to get true for selection[0] and selection[1], but not for selection[2] because selection[0] and [1] are object under the abstract class Metamodel.sysml.

Best regards,

Ka-lip

medini_1024169437

Ka-lip, I think I don't understand the use case and the scenario. You have 3 different elements selected, right? Which elements are that?

In my case I just had a single element selected and was doing different "instanceof" checks for that element. In your code snippet I cant judge what you are really doing.

Could you please clarify?

Thanks

Jan