Eclipse Community Forums: TMF (Xtext) » Differences in URI values

Help

Home

Home » Modeling » TMF (Xtext) » Differences in URI values

Show: Today's Messages :: Show Polls :: Message Navigator

Differences in URI values [message #1751843]

Mon, 16 January 2017 07:39

chris yo

Messages: 146
Registered: February 2013

Senior Member

I want to get the URI of my data.
So, I have this object called x.

I noticed that I can get the URI in different ways.
[1] x.eContainingFeature.eContainer.eResource.URI
[2] x.eResource.URI
[3] x.eContainer.eResource.URI

What are the differences of these 3 URI values? Should I expect them to always contain the same values?

[Updated on: Mon, 16 January 2017 07:40]

Report message to a moderator

Re: Differences in URI values [message #1751844 is a reply to message #1751843]

Mon, 16 January 2017 07:52

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

no

(2) and (3) should give you the same result,
but (1) navigates from the model to the metamodel and thus will give you the metamodels resource

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Differences in URI values [message #1751846 is a reply to message #1751844]

Mon, 16 January 2017 08:01

chris yo

Messages: 146
Registered: February 2013

Senior Member

sorry, i am not very familiar with the terminology.
what is the difference between model and metamodel?
what are the instances where the URI in model differs from the one in metamodel?

Report message to a moderator

Re: Differences in URI values [message #1751847 is a reply to message #1751846]

Mon, 16 January 2017 08:06

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

an easy analogy would be the terms classes and objects/instances

in emf lets say there is a class Person that has/owns an Adress what has an Attribute name
you have a Person "Hugo" that lives at "AStreet".

having the "AStreet" in hand "eContainer" will gives you "Hugo"
but eContainingFeature will give you "Field adress of Type Adress of Class Person"

i recommend some basic reading on EMF

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Differences in URI values [message #1751848 is a reply to message #1751847]

Mon, 16 January 2017 08:39

chris yo

Messages: 146
Registered: February 2013

Senior Member

Ok, thanks for the info.

Is there a way to set the eResource details? I found eSet() that will set the eContainingFeature. How to set the eResource variable?

Report message to a moderator

Re: Differences in URI values [message #1751849 is a reply to message #1751848]

Mon, 16 January 2017 09:00

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

you do it by added the root eobject to the resource.
but that should happend automatically.

can you elaborate on what you are doing?

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Differences in URI values [message #1751851 is a reply to message #1751849]

Mon, 16 January 2017 09:16

chris yo

Messages: 146
Registered: February 2013

Senior Member

I have two different but similar grammars.

Kids
-> name
-> address

Child
-> name
-> address

Kids is the old grammar. Then, I have to support the Child grammar. However, I have to treat both Kids and Child classes as one.
Thus, during transform, I add all the Child objects into the Kids object.
During generation and validation, I have to know the file and line number where each entry is configured.
So, I have this code:

for(m: rs.allContents.toIterable.filter(typeof(Child))) //rs is a ResourceSet
		{
			val x = MyDslFactory::eINSTANCE.createKids
			x.name = m.name
			x.address = m.address
			x.eSet(x.eContainingFeature, m.eContainingFeature)
			aKidsList.add(x)
		}

I haven't found any way to set the resource so I can retrieve the URI information later. How to do it?

Report message to a moderator

Re: Differences in URI values [message #1751854 is a reply to message #1751851]

Mon, 16 January 2017 09:59

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

which uri information? the one of m or the one of aKidsLists owner?

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Differences in URI values [message #1751859 is a reply to message #1751854]

Mon, 16 January 2017 10:29

chris yo

Messages: 146
Registered: February 2013

Senior Member

I want to copy the URI information of m to x.

Report message to a moderator

Re: Differences in URI values [message #1751861 is a reply to message #1751859]

Mon, 16 January 2017 10:30

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

then you have to create a string placeholder for that

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Differences in URI values [message #1751862 is a reply to message #1751861]

Mon, 16 January 2017 10:32

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

our you create a source cross reference for that

MyObject: ..... sourceEObject=[ecore::EObject|EObject] ...

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Differences in URI values [message #1751867 is a reply to message #1751862]

Mon, 16 January 2017 10:46

Sven Efftinge

Messages: 83
Registered: January 2016
Location: Kiel

Member

It's still unclear what you are trying to do but, you can create and attach EAdapters to EObject if you want to attach additional information.

Report message to a moderator

Re: Differences in URI values [message #1752025 is a reply to message #1751867]

Wed, 18 January 2017 03:02

chris yo

Messages: 146
Registered: February 2013

Senior Member

Thanks for the info. In the end, I decided to change the grammar as it is simpler to implement.

I noticed that the containing feature is also in the container itself.
Thus, is it safe to assume that for an object x:
x.eContainingFeature is always equal to x.eContainer.eContainingFeature?

Report message to a moderator

Re: Differences in URI values [message #1752029 is a reply to message #1752025]

Wed, 18 January 2017 03:45

Ed Merks

Messages: 32819
Registered: July 2009

Senior Member

No, this isn't a safe general assumption. The first is the feature of the container of x that actually contains x, i.e., you could call x.eContainer.eGet(x.eContainingFeature) and expect to find x in the result. The second is the feature that contains the container of x. They might be the same feature, but generally not because generally the container will have a completely different set of features because it's a completely different class of object.

Ed Merks
Professional Support: https://www.macromodeling.com/

Report message to a moderator

Previous Topic:	Ecore and GenModel annotation not found in xcore files
Next Topic:	Xtext Summit @ EclipseCon France

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

]

Current Time: Mon May 29 22:55:31 GMT 2023

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter