[news.eclipse.tools.emf] Re: Question re href and @children

[Ed Merks <Ed.Merks@xxxxxxxxx>]

Alan,

Comments below.

Alan wrote:
> Hello,
>
> I am having a strange issue with hrefs.
> I have 2 resources.
> In the first I have a number of Object As which contains a collection of 
> Object Bs (containment = true)
> (I also have something things above A but we'll focus on A and B for 
> example)
> In the second I have a reference to a collection of Object Bs (containment = 
> false)
>
> The href for one of the Object Bs in the second resource reads like this:
> href="resource1.config#//@children.2/@children.3/@myobjectBs.0
>
> The issue arises when I delete an Object A.
> In the first resource it is now found at @children.2/@children.2
> instead of at @children.2/@children.3
>   
Yes, that's expected.
> This only occurs if I delete an Object A that was not the last created one.
> In other words it seems as if that format is like an index.
>   
Yes, exactly.
> So when I delete one Object A any ObjectAs created after it have their 
> "indexes" updated.
>   
Indeed the format it fragile with respect to reordering.
> However the second resource does not update to reflect this.
>   
It makes a difference whether the proxy is resolved or not.  If it's not 
resolved yet, it will end up keeping the same proxy URI and will point 
to a different object.
> So when I try to restart the application the collection of ObjectBs from 
> resource 2 does not find an object.
>
> I confirmed that this was what was happening by changing the reference 
> manually in the xml file of the second resource
> So If I change index to reflect resource 1 it works fine.
>
> I tried making sure that resource1 was saved first and then resource2 but it 
> made no difference.
>   
Whether proxies have been resolved makes a difference.  
EcoreUtil.resolveAll can be used to force all proxies to be resolve.
> Has anyone any ideas as to why this is happening an how I might fix it ?
>   
If possible take advantage of EReference.eKeys.  I.e., identify an 
attribute or combination of attributes in A that make it unique with 
respect to the containment reference.   The serialization will then look 
like @children[key='value'] and will be resilient with respect to 
reordering.
> thanks,
> Alan.
>
>
>