Home » Modeling » EMF "Technology" (Ecore Tools, EMFatic, etc) » Querying of EModel
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Re: Querying of EModel [message #54088 is a reply to message #53586] |
Thu, 28 September 2006 13:30 |
Eclipse User |
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Originally posted by: cdamus.ca.ibm.com
Hi, Kamesh,
I think that EMF Query is most appropriate when the criteria for selecting
elements from the model are variable, because it allows plugging in OCL
expressions or a wide variety of recombinable Condition objects.
Often, though, the requirement is more simply satisfied by an
EcoreUtil.getAllContents(...) iterator with judicious use of the
TreeIterator.prune() method. You can also make a more responsive UI by
listening for model changes that add/remove values that you would put in
your list and keep a cache up-to-date, so that you don't have to scan the
whole model every time the list needs to be shown.
Cheers,
Christian
Kamesh Sampath wrote:
> Hi ,
> I have class called Department(id,name) and Employee(id,name,dept)
>
> I am creating a view with controls for altering the properties of the
> Employee model ( imagine like a SWT page with set of controls). I have
> drop down for the Employee.dept , the values for the dept dropdown must be
> from department.name .
>
> I have a small query in this , is EMF Query is the best suited technoligy
> for this purpose or is there any other best way to do it ?
>
> thanks.
> Kamesh
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Re: Querying of EModel [message #54142 is a reply to message #54088] |
Thu, 28 September 2006 13:49 |
Kamesh Sampath Messages: 191 Registered: July 2009 |
Senior Member |
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Hi Christian,
I agree to your thought .
Will i be able to change my dropdown(combo) contents based on model
changes ?
I am still not clear on the following,
iterator with judicious use of the
TreeIterator.prune() method
Can you please clarify on that ?
Please let me if this question is not to be asked on EMFT . Will post
the same in the concerned newsgroups.
Thanks.
Regards,
Kamesh
Christian W. Damus wrote:
> Hi, Kamesh,
>
> I think that EMF Query is most appropriate when the criteria for selecting
> elements from the model are variable, because it allows plugging in OCL
> expressions or a wide variety of recombinable Condition objects.
>
> Often, though, the requirement is more simply satisfied by an
> EcoreUtil.getAllContents(...) iterator with judicious use of the
> TreeIterator.prune() method. You can also make a more responsive UI by
> listening for model changes that add/remove values that you would put in
> your list and keep a cache up-to-date, so that you don't have to scan the
> whole model every time the list needs to be shown.
>
> Cheers,
>
> Christian
>
>
> Kamesh Sampath wrote:
>
>
>> Hi ,
>> I have class called Department(id,name) and Employee(id,name,dept)
>>
>> I am creating a view with controls for altering the properties of the
>> Employee model ( imagine like a SWT page with set of controls). I have
>> drop down for the Employee.dept , the values for the dept dropdown must be
>> from department.name .
>>
>> I have a small query in this , is EMF Query is the best suited technoligy
>> for this purpose or is there any other best way to do it ?
>>
>> thanks.
>> Kamesh
>>
>
>
--
Kamesh Sampath
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Re: Querying of EModel [message #54170 is a reply to message #54142] |
Thu, 28 September 2006 14:04 |
Eclipse User |
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Originally posted by: merks.ca.ibm.com
Kamesh,
EMF supports the concept of a tree iterator, which extends the Iterator
API with a method called prune(). Methods such as
ResourceSet/Resource.getAllContents and EObject.eAllContents return such
an iterator, as do various EcoreUtil.getAllContents/getAllProperContents
(all of which are based on EcoreUtil.TreeContentIterator or
AbstractTreeIterator). So you can easily iterate over the contents of a
tree to avoid needing to do it recursively, and you can use the prune()
method to avoid walking down a tree branch you don't want to visit. So
a quick tree walk to find all the objects matching some criterion is
very easy to write, and with appropriate pruning can be tuned to avoid
walking branches that can't lead to the results you are looking for.
Kamesh Sampath wrote:
> Hi Christian,
>
> I agree to your thought .
>
> Will i be able to change my dropdown(combo) contents based on model
> changes ?
>
> I am still not clear on the following,
>
> iterator with judicious use of the
> TreeIterator.prune() method
>
> Can you please clarify on that ?
>
> Please let me if this question is not to be asked on EMFT . Will post
> the same in the concerned newsgroups.
>
> Thanks.
>
> Regards,
> Kamesh
>
> Christian W. Damus wrote:
>> Hi, Kamesh,
>>
>> I think that EMF Query is most appropriate when the criteria for
>> selecting
>> elements from the model are variable, because it allows plugging in OCL
>> expressions or a wide variety of recombinable Condition objects.
>>
>> Often, though, the requirement is more simply satisfied by an
>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>> TreeIterator.prune() method. You can also make a more responsive UI by
>> listening for model changes that add/remove values that you would put in
>> your list and keep a cache up-to-date, so that you don't have to scan
>> the
>> whole model every time the list needs to be shown.
>>
>> Cheers,
>>
>> Christian
>>
>>
>> Kamesh Sampath wrote:
>>
>>
>>> Hi ,
>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>
>>> I am creating a view with controls for altering the properties of the
>>> Employee model ( imagine like a SWT page with set of controls). I have
>>> drop down for the Employee.dept , the values for the dept dropdown
>>> must be
>>> from department.name .
>>>
>>> I have a small query in this , is EMF Query is the best suited
>>> technoligy
>>> for this purpose or is there any other best way to do it ?
>>>
>>> thanks.
>>> Kamesh
>>>
>>
>>
>
>
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Re: Querying of EModel [message #54197 is a reply to message #54170] |
Thu, 28 September 2006 17:28 |
Kamesh Sampath Messages: 191 Registered: July 2009 |
Senior Member |
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Ed,
Thanks for the info on the TreeIterator ,
I have implemented the same and the code snippet is as follows,
Resource resource = ((Resource) editingDomain.getResourceSet()
.getResources().get(0));
StrutsConfigType root = (StrutsConfigType) resource.getContents()
.get(0);
TreeIterator iterator = EcoreUtil.getAllProperContents(root
.getFormBeans(), false);
ArrayList beanNames = new ArrayList();
while (iterator.hasNext()) {
Object obj = iterator.next();
// System.out.println(obj.getClass());
if (obj instanceof FormBeanType) {
FormBeanType beanType = (FormBeanType) obj;
if (beanType != null) {
System.out.println(beanType.getName());
beanNames.add(beanType.getName());
}
}
}
But i have not used purne(). Is this a right approach or there is any
other better way ??
thanks,
Kamesh
Ed Merks wrote:
> Kamesh,
>
> EMF supports the concept of a tree iterator, which extends the
> Iterator API with a method called prune(). Methods such as
> ResourceSet/Resource.getAllContents and EObject.eAllContents return
> such an iterator, as do various
> EcoreUtil.getAllContents/getAllProperContents (all of which are based
> on EcoreUtil.TreeContentIterator or AbstractTreeIterator). So you can
> easily iterate over the contents of a tree to avoid needing to do it
> recursively, and you can use the prune() method to avoid walking down
> a tree branch you don't want to visit. So a quick tree walk to find
> all the objects matching some criterion is very easy to write, and
> with appropriate pruning can be tuned to avoid walking branches that
> can't lead to the results you are looking for.
>
>
> Kamesh Sampath wrote:
>> Hi Christian,
>>
>> I agree to your thought .
>>
>> Will i be able to change my dropdown(combo) contents based on model
>> changes ?
>>
>> I am still not clear on the following,
>>
>> iterator with judicious use of the
>> TreeIterator.prune() method
>>
>> Can you please clarify on that ?
>>
>> Please let me if this question is not to be asked on EMFT . Will post
>> the same in the concerned newsgroups.
>>
>> Thanks.
>>
>> Regards,
>> Kamesh
>>
>> Christian W. Damus wrote:
>>> Hi, Kamesh,
>>>
>>> I think that EMF Query is most appropriate when the criteria for
>>> selecting
>>> elements from the model are variable, because it allows plugging in OCL
>>> expressions or a wide variety of recombinable Condition objects.
>>>
>>> Often, though, the requirement is more simply satisfied by an
>>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>>> TreeIterator.prune() method. You can also make a more responsive UI by
>>> listening for model changes that add/remove values that you would
>>> put in
>>> your list and keep a cache up-to-date, so that you don't have to
>>> scan the
>>> whole model every time the list needs to be shown.
>>>
>>> Cheers,
>>>
>>> Christian
>>>
>>>
>>> Kamesh Sampath wrote:
>>>
>>>
>>>> Hi ,
>>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>>
>>>> I am creating a view with controls for altering the properties of the
>>>> Employee model ( imagine like a SWT page with set of controls). I have
>>>> drop down for the Employee.dept , the values for the dept dropdown
>>>> must be
>>>> from department.name .
>>>>
>>>> I have a small query in this , is EMF Query is the best suited
>>>> technoligy
>>>> for this purpose or is there any other best way to do it ?
>>>>
>>>> thanks.
>>>> Kamesh
>>>>
>>>
>>>
>>
>>
--
Kamesh Sampath
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Re: Querying of EModel [message #54223 is a reply to message #54197] |
Thu, 28 September 2006 17:41 |
Eclipse User |
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Originally posted by: merks.ca.ibm.com
Kamesh,
This looks fine. Note that the beanType != null guard is redundant.
Firstly, because the tree iterator will never return null and secondly
because the instanceof FormBeanType test will not return true for null.
Kamesh Sampath wrote:
> Ed,
>
> Thanks for the info on the TreeIterator ,
>
> I have implemented the same and the code snippet is as follows,
>
> Resource resource = ((Resource) editingDomain.getResourceSet()
> .getResources().get(0));
> StrutsConfigType root = (StrutsConfigType) resource.getContents()
> .get(0);
> TreeIterator iterator = EcoreUtil.getAllProperContents(root
> .getFormBeans(), false);
> ArrayList beanNames = new ArrayList();
> while (iterator.hasNext()) {
> Object obj = iterator.next();
> // System.out.println(obj.getClass());
> if (obj instanceof FormBeanType) {
> FormBeanType beanType = (FormBeanType) obj;
> if (beanType != null) {
> System.out.println(beanType.getName());
> beanNames.add(beanType.getName());
> }
> }
> }
>
> But i have not used purne(). Is this a right approach or there is any
> other better way ??
>
> thanks,
> Kamesh
>
> Ed Merks wrote:
>> Kamesh,
>>
>> EMF supports the concept of a tree iterator, which extends the
>> Iterator API with a method called prune(). Methods such as
>> ResourceSet/Resource.getAllContents and EObject.eAllContents return
>> such an iterator, as do various
>> EcoreUtil.getAllContents/getAllProperContents (all of which are based
>> on EcoreUtil.TreeContentIterator or AbstractTreeIterator). So you
>> can easily iterate over the contents of a tree to avoid needing to do
>> it recursively, and you can use the prune() method to avoid walking
>> down a tree branch you don't want to visit. So a quick tree walk to
>> find all the objects matching some criterion is very easy to write,
>> and with appropriate pruning can be tuned to avoid walking branches
>> that can't lead to the results you are looking for.
>>
>>
>> Kamesh Sampath wrote:
>>> Hi Christian,
>>>
>>> I agree to your thought .
>>>
>>> Will i be able to change my dropdown(combo) contents based on model
>>> changes ?
>>>
>>> I am still not clear on the following,
>>>
>>> iterator with judicious use of the
>>> TreeIterator.prune() method
>>>
>>> Can you please clarify on that ?
>>>
>>> Please let me if this question is not to be asked on EMFT . Will
>>> post the same in the concerned newsgroups.
>>>
>>> Thanks.
>>>
>>> Regards,
>>> Kamesh
>>>
>>> Christian W. Damus wrote:
>>>> Hi, Kamesh,
>>>>
>>>> I think that EMF Query is most appropriate when the criteria for
>>>> selecting
>>>> elements from the model are variable, because it allows plugging in
>>>> OCL
>>>> expressions or a wide variety of recombinable Condition objects.
>>>>
>>>> Often, though, the requirement is more simply satisfied by an
>>>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>>>> TreeIterator.prune() method. You can also make a more responsive
>>>> UI by
>>>> listening for model changes that add/remove values that you would
>>>> put in
>>>> your list and keep a cache up-to-date, so that you don't have to
>>>> scan the
>>>> whole model every time the list needs to be shown.
>>>>
>>>> Cheers,
>>>>
>>>> Christian
>>>>
>>>>
>>>> Kamesh Sampath wrote:
>>>>
>>>>
>>>>> Hi ,
>>>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>>>
>>>>> I am creating a view with controls for altering the properties of the
>>>>> Employee model ( imagine like a SWT page with set of controls). I
>>>>> have
>>>>> drop down for the Employee.dept , the values for the dept dropdown
>>>>> must be
>>>>> from department.name .
>>>>>
>>>>> I have a small query in this , is EMF Query is the best suited
>>>>> technoligy
>>>>> for this purpose or is there any other best way to do it ?
>>>>>
>>>>> thanks.
>>>>> Kamesh
>>>>>
>>>>
>>>>
>>>
>>>
>
>
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Re: Querying of EModel [message #54328 is a reply to message #54223] |
Fri, 29 September 2006 03:11 |
Kamesh Sampath Messages: 191 Registered: July 2009 |
Senior Member |
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Ed,
thanks a lot !
Regards,
Kamesh
Ed Merks wrote:
> Kamesh,
>
> This looks fine. Note that the beanType != null guard is redundant.
> Firstly, because the tree iterator will never return null and secondly
> because the instanceof FormBeanType test will not return true for null.
>
>
> Kamesh Sampath wrote:
>> Ed,
>>
>> Thanks for the info on the TreeIterator ,
>>
>> I have implemented the same and the code snippet is as follows,
>>
>> Resource resource = ((Resource) editingDomain.getResourceSet()
>> .getResources().get(0));
>> StrutsConfigType root = (StrutsConfigType) resource.getContents()
>> .get(0);
>> TreeIterator iterator = EcoreUtil.getAllProperContents(root
>> .getFormBeans(), false);
>> ArrayList beanNames = new ArrayList();
>> while (iterator.hasNext()) {
>> Object obj = iterator.next();
>> // System.out.println(obj.getClass());
>> if (obj instanceof FormBeanType) {
>> FormBeanType beanType = (FormBeanType) obj;
>> if (beanType != null) {
>> System.out.println(beanType.getName());
>> beanNames.add(beanType.getName());
>> }
>> }
>> }
>>
>> But i have not used purne(). Is this a right approach or there is any
>> other better way ??
>>
>> thanks,
>> Kamesh
>>
>> Ed Merks wrote:
>>> Kamesh,
>>>
>>> EMF supports the concept of a tree iterator, which extends the
>>> Iterator API with a method called prune(). Methods such as
>>> ResourceSet/Resource.getAllContents and EObject.eAllContents return
>>> such an iterator, as do various
>>> EcoreUtil.getAllContents/getAllProperContents (all of which are
>>> based on EcoreUtil.TreeContentIterator or AbstractTreeIterator). So
>>> you can easily iterate over the contents of a tree to avoid needing
>>> to do it recursively, and you can use the prune() method to avoid
>>> walking down a tree branch you don't want to visit. So a quick tree
>>> walk to find all the objects matching some criterion is very easy to
>>> write, and with appropriate pruning can be tuned to avoid walking
>>> branches that can't lead to the results you are looking for.
>>>
>>>
>>> Kamesh Sampath wrote:
>>>> Hi Christian,
>>>>
>>>> I agree to your thought .
>>>>
>>>> Will i be able to change my dropdown(combo) contents based on model
>>>> changes ?
>>>>
>>>> I am still not clear on the following,
>>>>
>>>> iterator with judicious use of the
>>>> TreeIterator.prune() method
>>>>
>>>> Can you please clarify on that ?
>>>>
>>>> Please let me if this question is not to be asked on EMFT . Will
>>>> post the same in the concerned newsgroups.
>>>>
>>>> Thanks.
>>>>
>>>> Regards,
>>>> Kamesh
>>>>
>>>> Christian W. Damus wrote:
>>>>> Hi, Kamesh,
>>>>>
>>>>> I think that EMF Query is most appropriate when the criteria for
>>>>> selecting
>>>>> elements from the model are variable, because it allows plugging
>>>>> in OCL
>>>>> expressions or a wide variety of recombinable Condition objects.
>>>>>
>>>>> Often, though, the requirement is more simply satisfied by an
>>>>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>>>>> TreeIterator.prune() method. You can also make a more responsive
>>>>> UI by
>>>>> listening for model changes that add/remove values that you would
>>>>> put in
>>>>> your list and keep a cache up-to-date, so that you don't have to
>>>>> scan the
>>>>> whole model every time the list needs to be shown.
>>>>>
>>>>> Cheers,
>>>>>
>>>>> Christian
>>>>>
>>>>>
>>>>> Kamesh Sampath wrote:
>>>>>
>>>>>
>>>>>> Hi ,
>>>>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>>>>
>>>>>> I am creating a view with controls for altering the properties of
>>>>>> the
>>>>>> Employee model ( imagine like a SWT page with set of controls). I
>>>>>> have
>>>>>> drop down for the Employee.dept , the values for the dept
>>>>>> dropdown must be
>>>>>> from department.name .
>>>>>>
>>>>>> I have a small query in this , is EMF Query is the best suited
>>>>>> technoligy
>>>>>> for this purpose or is there any other best way to do it ?
>>>>>>
>>>>>> thanks.
>>>>>> Kamesh
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>
>>
--
Kamesh Sampath
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Re: Querying of EModel [message #592540 is a reply to message #53586] |
Thu, 28 September 2006 13:30 |
Eclipse User |
|
|
|
Originally posted by: cdamus.ca.ibm.com
Hi, Kamesh,
I think that EMF Query is most appropriate when the criteria for selecting
elements from the model are variable, because it allows plugging in OCL
expressions or a wide variety of recombinable Condition objects.
Often, though, the requirement is more simply satisfied by an
EcoreUtil.getAllContents(...) iterator with judicious use of the
TreeIterator.prune() method. You can also make a more responsive UI by
listening for model changes that add/remove values that you would put in
your list and keep a cache up-to-date, so that you don't have to scan the
whole model every time the list needs to be shown.
Cheers,
Christian
Kamesh Sampath wrote:
> Hi ,
> I have class called Department(id,name) and Employee(id,name,dept)
>
> I am creating a view with controls for altering the properties of the
> Employee model ( imagine like a SWT page with set of controls). I have
> drop down for the Employee.dept , the values for the dept dropdown must be
> from department.name .
>
> I have a small query in this , is EMF Query is the best suited technoligy
> for this purpose or is there any other best way to do it ?
>
> thanks.
> Kamesh
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Re: Querying of EModel [message #592555 is a reply to message #54088] |
Thu, 28 September 2006 13:49 |
Kamesh Sampath Messages: 191 Registered: July 2009 |
Senior Member |
|
|
Hi Christian,
I agree to your thought .
Will i be able to change my dropdown(combo) contents based on model
changes ?
I am still not clear on the following,
iterator with judicious use of the
TreeIterator.prune() method
Can you please clarify on that ?
Please let me if this question is not to be asked on EMFT . Will post
the same in the concerned newsgroups.
Thanks.
Regards,
Kamesh
Christian W. Damus wrote:
> Hi, Kamesh,
>
> I think that EMF Query is most appropriate when the criteria for selecting
> elements from the model are variable, because it allows plugging in OCL
> expressions or a wide variety of recombinable Condition objects.
>
> Often, though, the requirement is more simply satisfied by an
> EcoreUtil.getAllContents(...) iterator with judicious use of the
> TreeIterator.prune() method. You can also make a more responsive UI by
> listening for model changes that add/remove values that you would put in
> your list and keep a cache up-to-date, so that you don't have to scan the
> whole model every time the list needs to be shown.
>
> Cheers,
>
> Christian
>
>
> Kamesh Sampath wrote:
>
>
>> Hi ,
>> I have class called Department(id,name) and Employee(id,name,dept)
>>
>> I am creating a view with controls for altering the properties of the
>> Employee model ( imagine like a SWT page with set of controls). I have
>> drop down for the Employee.dept , the values for the dept dropdown must be
>> from department.name .
>>
>> I have a small query in this , is EMF Query is the best suited technoligy
>> for this purpose or is there any other best way to do it ?
>>
>> thanks.
>> Kamesh
>>
>
>
--
Kamesh Sampath
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Re: Querying of EModel [message #592571 is a reply to message #54142] |
Thu, 28 September 2006 14:04 |
Ed Merks Messages: 33252 Registered: July 2009 |
Senior Member |
|
|
Kamesh,
EMF supports the concept of a tree iterator, which extends the Iterator
API with a method called prune(). Methods such as
ResourceSet/Resource.getAllContents and EObject.eAllContents return such
an iterator, as do various EcoreUtil.getAllContents/getAllProperContents
(all of which are based on EcoreUtil.TreeContentIterator or
AbstractTreeIterator). So you can easily iterate over the contents of a
tree to avoid needing to do it recursively, and you can use the prune()
method to avoid walking down a tree branch you don't want to visit. So
a quick tree walk to find all the objects matching some criterion is
very easy to write, and with appropriate pruning can be tuned to avoid
walking branches that can't lead to the results you are looking for.
Kamesh Sampath wrote:
> Hi Christian,
>
> I agree to your thought .
>
> Will i be able to change my dropdown(combo) contents based on model
> changes ?
>
> I am still not clear on the following,
>
> iterator with judicious use of the
> TreeIterator.prune() method
>
> Can you please clarify on that ?
>
> Please let me if this question is not to be asked on EMFT . Will post
> the same in the concerned newsgroups.
>
> Thanks.
>
> Regards,
> Kamesh
>
> Christian W. Damus wrote:
>> Hi, Kamesh,
>>
>> I think that EMF Query is most appropriate when the criteria for
>> selecting
>> elements from the model are variable, because it allows plugging in OCL
>> expressions or a wide variety of recombinable Condition objects.
>>
>> Often, though, the requirement is more simply satisfied by an
>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>> TreeIterator.prune() method. You can also make a more responsive UI by
>> listening for model changes that add/remove values that you would put in
>> your list and keep a cache up-to-date, so that you don't have to scan
>> the
>> whole model every time the list needs to be shown.
>>
>> Cheers,
>>
>> Christian
>>
>>
>> Kamesh Sampath wrote:
>>
>>
>>> Hi ,
>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>
>>> I am creating a view with controls for altering the properties of the
>>> Employee model ( imagine like a SWT page with set of controls). I have
>>> drop down for the Employee.dept , the values for the dept dropdown
>>> must be
>>> from department.name .
>>>
>>> I have a small query in this , is EMF Query is the best suited
>>> technoligy
>>> for this purpose or is there any other best way to do it ?
>>>
>>> thanks.
>>> Kamesh
>>>
>>
>>
>
>
Ed Merks
Professional Support: https://www.macromodeling.com/
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Re: Querying of EModel [message #592579 is a reply to message #54170] |
Thu, 28 September 2006 17:28 |
Kamesh Sampath Messages: 191 Registered: July 2009 |
Senior Member |
|
|
Ed,
Thanks for the info on the TreeIterator ,
I have implemented the same and the code snippet is as follows,
Resource resource = ((Resource) editingDomain.getResourceSet()
.getResources().get(0));
StrutsConfigType root = (StrutsConfigType) resource.getContents()
.get(0);
TreeIterator iterator = EcoreUtil.getAllProperContents(root
.getFormBeans(), false);
ArrayList beanNames = new ArrayList();
while (iterator.hasNext()) {
Object obj = iterator.next();
// System.out.println(obj.getClass());
if (obj instanceof FormBeanType) {
FormBeanType beanType = (FormBeanType) obj;
if (beanType != null) {
System.out.println(beanType.getName());
beanNames.add(beanType.getName());
}
}
}
But i have not used purne(). Is this a right approach or there is any
other better way ??
thanks,
Kamesh
Ed Merks wrote:
> Kamesh,
>
> EMF supports the concept of a tree iterator, which extends the
> Iterator API with a method called prune(). Methods such as
> ResourceSet/Resource.getAllContents and EObject.eAllContents return
> such an iterator, as do various
> EcoreUtil.getAllContents/getAllProperContents (all of which are based
> on EcoreUtil.TreeContentIterator or AbstractTreeIterator). So you can
> easily iterate over the contents of a tree to avoid needing to do it
> recursively, and you can use the prune() method to avoid walking down
> a tree branch you don't want to visit. So a quick tree walk to find
> all the objects matching some criterion is very easy to write, and
> with appropriate pruning can be tuned to avoid walking branches that
> can't lead to the results you are looking for.
>
>
> Kamesh Sampath wrote:
>> Hi Christian,
>>
>> I agree to your thought .
>>
>> Will i be able to change my dropdown(combo) contents based on model
>> changes ?
>>
>> I am still not clear on the following,
>>
>> iterator with judicious use of the
>> TreeIterator.prune() method
>>
>> Can you please clarify on that ?
>>
>> Please let me if this question is not to be asked on EMFT . Will post
>> the same in the concerned newsgroups.
>>
>> Thanks.
>>
>> Regards,
>> Kamesh
>>
>> Christian W. Damus wrote:
>>> Hi, Kamesh,
>>>
>>> I think that EMF Query is most appropriate when the criteria for
>>> selecting
>>> elements from the model are variable, because it allows plugging in OCL
>>> expressions or a wide variety of recombinable Condition objects.
>>>
>>> Often, though, the requirement is more simply satisfied by an
>>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>>> TreeIterator.prune() method. You can also make a more responsive UI by
>>> listening for model changes that add/remove values that you would
>>> put in
>>> your list and keep a cache up-to-date, so that you don't have to
>>> scan the
>>> whole model every time the list needs to be shown.
>>>
>>> Cheers,
>>>
>>> Christian
>>>
>>>
>>> Kamesh Sampath wrote:
>>>
>>>
>>>> Hi ,
>>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>>
>>>> I am creating a view with controls for altering the properties of the
>>>> Employee model ( imagine like a SWT page with set of controls). I have
>>>> drop down for the Employee.dept , the values for the dept dropdown
>>>> must be
>>>> from department.name .
>>>>
>>>> I have a small query in this , is EMF Query is the best suited
>>>> technoligy
>>>> for this purpose or is there any other best way to do it ?
>>>>
>>>> thanks.
>>>> Kamesh
>>>>
>>>
>>>
>>
>>
--
Kamesh Sampath
|
|
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Re: Querying of EModel [message #592590 is a reply to message #54197] |
Thu, 28 September 2006 17:41 |
Ed Merks Messages: 33252 Registered: July 2009 |
Senior Member |
|
|
Kamesh,
This looks fine. Note that the beanType != null guard is redundant.
Firstly, because the tree iterator will never return null and secondly
because the instanceof FormBeanType test will not return true for null.
Kamesh Sampath wrote:
> Ed,
>
> Thanks for the info on the TreeIterator ,
>
> I have implemented the same and the code snippet is as follows,
>
> Resource resource = ((Resource) editingDomain.getResourceSet()
> .getResources().get(0));
> StrutsConfigType root = (StrutsConfigType) resource.getContents()
> .get(0);
> TreeIterator iterator = EcoreUtil.getAllProperContents(root
> .getFormBeans(), false);
> ArrayList beanNames = new ArrayList();
> while (iterator.hasNext()) {
> Object obj = iterator.next();
> // System.out.println(obj.getClass());
> if (obj instanceof FormBeanType) {
> FormBeanType beanType = (FormBeanType) obj;
> if (beanType != null) {
> System.out.println(beanType.getName());
> beanNames.add(beanType.getName());
> }
> }
> }
>
> But i have not used purne(). Is this a right approach or there is any
> other better way ??
>
> thanks,
> Kamesh
>
> Ed Merks wrote:
>> Kamesh,
>>
>> EMF supports the concept of a tree iterator, which extends the
>> Iterator API with a method called prune(). Methods such as
>> ResourceSet/Resource.getAllContents and EObject.eAllContents return
>> such an iterator, as do various
>> EcoreUtil.getAllContents/getAllProperContents (all of which are based
>> on EcoreUtil.TreeContentIterator or AbstractTreeIterator). So you
>> can easily iterate over the contents of a tree to avoid needing to do
>> it recursively, and you can use the prune() method to avoid walking
>> down a tree branch you don't want to visit. So a quick tree walk to
>> find all the objects matching some criterion is very easy to write,
>> and with appropriate pruning can be tuned to avoid walking branches
>> that can't lead to the results you are looking for.
>>
>>
>> Kamesh Sampath wrote:
>>> Hi Christian,
>>>
>>> I agree to your thought .
>>>
>>> Will i be able to change my dropdown(combo) contents based on model
>>> changes ?
>>>
>>> I am still not clear on the following,
>>>
>>> iterator with judicious use of the
>>> TreeIterator.prune() method
>>>
>>> Can you please clarify on that ?
>>>
>>> Please let me if this question is not to be asked on EMFT . Will
>>> post the same in the concerned newsgroups.
>>>
>>> Thanks.
>>>
>>> Regards,
>>> Kamesh
>>>
>>> Christian W. Damus wrote:
>>>> Hi, Kamesh,
>>>>
>>>> I think that EMF Query is most appropriate when the criteria for
>>>> selecting
>>>> elements from the model are variable, because it allows plugging in
>>>> OCL
>>>> expressions or a wide variety of recombinable Condition objects.
>>>>
>>>> Often, though, the requirement is more simply satisfied by an
>>>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>>>> TreeIterator.prune() method. You can also make a more responsive
>>>> UI by
>>>> listening for model changes that add/remove values that you would
>>>> put in
>>>> your list and keep a cache up-to-date, so that you don't have to
>>>> scan the
>>>> whole model every time the list needs to be shown.
>>>>
>>>> Cheers,
>>>>
>>>> Christian
>>>>
>>>>
>>>> Kamesh Sampath wrote:
>>>>
>>>>
>>>>> Hi ,
>>>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>>>
>>>>> I am creating a view with controls for altering the properties of the
>>>>> Employee model ( imagine like a SWT page with set of controls). I
>>>>> have
>>>>> drop down for the Employee.dept , the values for the dept dropdown
>>>>> must be
>>>>> from department.name .
>>>>>
>>>>> I have a small query in this , is EMF Query is the best suited
>>>>> technoligy
>>>>> for this purpose or is there any other best way to do it ?
>>>>>
>>>>> thanks.
>>>>> Kamesh
>>>>>
>>>>
>>>>
>>>
>>>
>
>
Ed Merks
Professional Support: https://www.macromodeling.com/
|
|
|
Re: Querying of EModel [message #592633 is a reply to message #54223] |
Fri, 29 September 2006 03:11 |
Kamesh Sampath Messages: 191 Registered: July 2009 |
Senior Member |
|
|
Ed,
thanks a lot !
Regards,
Kamesh
Ed Merks wrote:
> Kamesh,
>
> This looks fine. Note that the beanType != null guard is redundant.
> Firstly, because the tree iterator will never return null and secondly
> because the instanceof FormBeanType test will not return true for null.
>
>
> Kamesh Sampath wrote:
>> Ed,
>>
>> Thanks for the info on the TreeIterator ,
>>
>> I have implemented the same and the code snippet is as follows,
>>
>> Resource resource = ((Resource) editingDomain.getResourceSet()
>> .getResources().get(0));
>> StrutsConfigType root = (StrutsConfigType) resource.getContents()
>> .get(0);
>> TreeIterator iterator = EcoreUtil.getAllProperContents(root
>> .getFormBeans(), false);
>> ArrayList beanNames = new ArrayList();
>> while (iterator.hasNext()) {
>> Object obj = iterator.next();
>> // System.out.println(obj.getClass());
>> if (obj instanceof FormBeanType) {
>> FormBeanType beanType = (FormBeanType) obj;
>> if (beanType != null) {
>> System.out.println(beanType.getName());
>> beanNames.add(beanType.getName());
>> }
>> }
>> }
>>
>> But i have not used purne(). Is this a right approach or there is any
>> other better way ??
>>
>> thanks,
>> Kamesh
>>
>> Ed Merks wrote:
>>> Kamesh,
>>>
>>> EMF supports the concept of a tree iterator, which extends the
>>> Iterator API with a method called prune(). Methods such as
>>> ResourceSet/Resource.getAllContents and EObject.eAllContents return
>>> such an iterator, as do various
>>> EcoreUtil.getAllContents/getAllProperContents (all of which are
>>> based on EcoreUtil.TreeContentIterator or AbstractTreeIterator). So
>>> you can easily iterate over the contents of a tree to avoid needing
>>> to do it recursively, and you can use the prune() method to avoid
>>> walking down a tree branch you don't want to visit. So a quick tree
>>> walk to find all the objects matching some criterion is very easy to
>>> write, and with appropriate pruning can be tuned to avoid walking
>>> branches that can't lead to the results you are looking for.
>>>
>>>
>>> Kamesh Sampath wrote:
>>>> Hi Christian,
>>>>
>>>> I agree to your thought .
>>>>
>>>> Will i be able to change my dropdown(combo) contents based on model
>>>> changes ?
>>>>
>>>> I am still not clear on the following,
>>>>
>>>> iterator with judicious use of the
>>>> TreeIterator.prune() method
>>>>
>>>> Can you please clarify on that ?
>>>>
>>>> Please let me if this question is not to be asked on EMFT . Will
>>>> post the same in the concerned newsgroups.
>>>>
>>>> Thanks.
>>>>
>>>> Regards,
>>>> Kamesh
>>>>
>>>> Christian W. Damus wrote:
>>>>> Hi, Kamesh,
>>>>>
>>>>> I think that EMF Query is most appropriate when the criteria for
>>>>> selecting
>>>>> elements from the model are variable, because it allows plugging
>>>>> in OCL
>>>>> expressions or a wide variety of recombinable Condition objects.
>>>>>
>>>>> Often, though, the requirement is more simply satisfied by an
>>>>> EcoreUtil.getAllContents(...) iterator with judicious use of the
>>>>> TreeIterator.prune() method. You can also make a more responsive
>>>>> UI by
>>>>> listening for model changes that add/remove values that you would
>>>>> put in
>>>>> your list and keep a cache up-to-date, so that you don't have to
>>>>> scan the
>>>>> whole model every time the list needs to be shown.
>>>>>
>>>>> Cheers,
>>>>>
>>>>> Christian
>>>>>
>>>>>
>>>>> Kamesh Sampath wrote:
>>>>>
>>>>>
>>>>>> Hi ,
>>>>>> I have class called Department(id,name) and Employee(id,name,dept)
>>>>>>
>>>>>> I am creating a view with controls for altering the properties of
>>>>>> the
>>>>>> Employee model ( imagine like a SWT page with set of controls). I
>>>>>> have
>>>>>> drop down for the Employee.dept , the values for the dept
>>>>>> dropdown must be
>>>>>> from department.name .
>>>>>>
>>>>>> I have a small query in this , is EMF Query is the best suited
>>>>>> technoligy
>>>>>> for this purpose or is there any other best way to do it ?
>>>>>>
>>>>>> thanks.
>>>>>> Kamesh
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>
>>
--
Kamesh Sampath
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