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From Marshall Schor <...@schor.com>
Subject Re: Retrieving annotator back from analysis engine
Date Thu, 30 Mar 2017 21:22:08 GMT
Hi James,

Here's an approach, which may or may not be appropriate:

Instead of wrapping each annotator as a separate analysis engine, make just one
analysis engine with all the annotators in it, as an aggregate, and give that
aggregate a custom flow controller.

Flow controllers were architected for the use case that you describe.

There's an example flow controller in the uimaj-examples project
(WhiteboardFlowController), also you can see here:
https://svn.apache.org/repos/asf/uima/uimaj/tags/uimaj-2.9.0/uimaj-examples/src/main/java/org/apache/uima/examples/flow/WhiteboardFlowController.java

This flow controller looks in the CAS after each annotator, and based on what it
sees has been added, figures out which annotator has their requirements met, and
runs it next.

I suspect this would be a more efficient and direct way to implement what you want.

Also see:
http://uima.apache.org/d/uimaj-current/tutorials_and_users_guides.html#ugr.tug.fc
- it describes this whiteboard flow controller example a bit.

Would this work for you?

-Marshall

On 3/30/2017 10:24 AM, James Baker wrote:
> Thanks Marshall,
>
> What I have is each annotator wrapped as a separate analysis engine
> ("pipeline"), and then I'm manually running each of those in turn because I
> want to be able to control the order. In fact, what I'm really trying to
> achieve is controlling the order that the annotators are run in, based
> information I get back from them.
>
> Surely the analysis engine/resource specifier must have some kind of
> reference back to the original class, otherwise how does it know what code
> to run? Perhaps there's not a method at the moment to get back to the
> original annotator, but is it stored somewhere I could get to via
> reflection (accepting all the risks and bad practices that entails!)
>
> James
>
> On 30 March 2017 at 15:07, Marshall Schor <msa@schor.com> wrote:
>
>> Hi James,
>>
>> The UIMA terminology discusses two kinds of entities:
>>
>>   a) Annotators - take a CAS in, operate on it, update it, etc.  These are
>> the
>> building blocks of pipelines.
>>
>>   b) UIMA Applications (e.g., "pipelines") made up of some collection of
>> Annotators.
>>
>> In most UIMA applications, there might be 1 pipeline, each having a number
>> of
>> Annotators. Is this what you have?  Or are you running multiple (perhaps
>> different) collections of annotators, each having its own pipeline?
>>
>> The produceAnalysisEngine call takes an object which is a
>> ResourceSpecifier.
>> That object is a description of the entire pipeline - what annotators are
>> in it,
>> configuration parameters, etc.  The output of that is an AnalysisEngine
>> object
>> that represents the whole pipeline.
>>
>> There's no reference from that AnalysisEngine object back to the
>> ResourceSpecifier that was used to direct the construction of the pipeline.
>>
>> So, I don't think what you want to do can be done.
>>
>> ============
>>
>> That being said, perhaps the high level design can be adjusted.  I'm
>> wondering
>> if two things got a bit conflated in the design - the idea of analysis
>> engine
>> "components" (e.g. Annotators) and the idea of analysis engines themselves
>> (the
>> pipelines that contain the annotators, configuration data, etc.)?
>>
>> -Marshall
>>
>>
>> On 3/29/2017 1:11 PM, James Baker wrote:
>>> In my UIMA application, I have a number of AnalysisEngines (as you might
>>> expect). These were created using UIMAFramework.
>> produceAnalysisEngine(...)
>>> on my annotators, which all extend MyAnnotator (which in turn extends
>>> JCasAnnotator_ImplBase).
>>>
>>> I want to get from the AnalysisEngine back to the original class (cast to
>>> MyAnnotator) so that I can access some of the additional functions I've
>>> added to the class. However, I can't seem to work out how to do that.
>> Could
>>> someone give some pointers?
>>>
>>> For clarity, I've included below some code of what I'm trying to acheive
>>> (I'm aware that the code below doesn't work as I've tried it!)
>>>
>>> ----------------------------
>>>
>>> AnalysisEngine ae = getAnalysisEngine(); //Get the analysis engine from
>>> whereever it is, this bit's not important
>>>
>>> MyAnnotator ma = (MyAnnotator) ae; //Throws ClassCastException
>>> ma.callMyFunction(); //This is what I'm really trying to get to
>>>
>>> ----------------------------
>>>
>>> Thanks,
>>> James
>>>
>>


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