EMA - Batch request with specific fields

samer.masaad
samer.masaad
in EMA

For better performance, I'm trying to request specific fields using a batch request. For example, I want to get only the BID and ASK fields from the EUR= and GBP= requests. I'm using this code:

ElementList customView = EmaFactory.createElementList();
OmmArray fields_array = EmaFactory.createOmmArray();
OmmArray batch_array = EmaFactory.createOmmArray();

fields_array.fixedWidth(2);
fields_array.add(EmaFactory.createOmmArrayEntry().intValue(22)); // BID
fields_array.add(EmaFactory.createOmmArrayEntry().intValue(25)); // ASK

batch_array.add(EmaFactory.createOmmArrayEntry().ascii('EUR='));
batch_array.add(EmaFactory.createOmmArrayEntry().ascii('GBP='));

customView.add(EmaFactory.createElementEntry().uintValue(EmaRdm.ENAME_VIEW_TYPE, 1));
customView.add(EmaFactory.createElementEntry().array(EmaRdm.ENAME_VIEW_DATA, fields_array));
customView.add(EmaFactory.createElementEntry().array(EmaRdm.ENAME_BATCH_ITEM_LIST, batch_array));

this.consumer.registerClient(EmaFactory.createReqMsg().serviceName(serviceName).payload(customView), this.appClient);

I'm having this Exception:

Exception Type='OmmInvalidUsageException', Text='Failed to open or modify item request. Reason: ReactorReturnCodes.FAILURE. Error text: Unexpected primitive type in array  <17>'
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Best Answer

  • umer.nalla
    umer.nalla
    Answer ✓

    Hi @samer.masaad

    I suspect this could be because you are using single quote rather than double quote for your RIC codes and also the order of adding the arrays to the ElemenList seems to matter.

    so, for example the following works for me:

    ElementList customView = EmaFactory.createElementList(); 
    OmmArray fields_array = EmaFactory.createOmmArray(); 
    OmmArray batch_array = EmaFactory.createOmmArray(); 

    fields_array.fixedWidth(2); 
    fields_array.add(EmaFactory.createOmmArrayEntry().intValue(22)); // BID 
    fields_array.add(EmaFactory.createOmmArrayEntry().intValue(25)); // ASK 
    batch_array.add(EmaFactory.createOmmArrayEntry().ascii("EUR=")); 
    batch_array.add(EmaFactory.createOmmArrayEntry().ascii("GBP=")); 


    customView.add(EmaFactory.createElementEntry().array(EmaRdm.ENAME_BATCH_ITEM_LIST, batch_array)); 
    customView.add(EmaFactory.createElementEntry().uintValue(EmaRdm.ENAME_VIEW_TYPE, 1)); 
    customView.add(EmaFactory.createElementEntry().array(EmaRdm.ENAME_VIEW_DATA, fields_array));


    On my Java environment your code snippet wont get past compilation due to an invalid character constant error....

Answers

  • samer.masaad
    samer.masaad

    Good morning and thank you for you answer.
    Your code actually worked! But not because of the quotes, since I'm using variables here whose values are loaded from somewhere else, not strings with quotes. But the problem appeared to be in the sequence of the last 3 lines. In my code I was setting the uintValue first, then the fields_array, and finally the batch_array. The sequence in your code worked and saved my day. Thank you again.

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