How to fetch multiple Symbols data by making one call for EMA?(Ex : Sym1,Sym2,Sym3....)is it correct

priyanka.mundargi

How to fetch multiple Symbols data by making one call for EMA?(Ex : Sym1,Sym2,Sym3....)is it correct way: consumer.registerClient(reqMsg.serviceName("ABC").name("Sym1,Sym2,Sym3"), appClient);?

pimchaya.wongrukun01

Hello @priyanka.mundargi

An EMA consumer application can request multiple items using a single request called a batch
request. After the consumer sends an batch request to the
ADS, the ADS responds by sending the items as if they were opened individually
so the items can be managed individually as shown in the figure below:

Hence, your EMA application just once calls OmmConsumer.registerClient(..) specifying array of multiple Symbols.

A snipped
source code in EMA Java:

ElementList batch = EmaFactory.createElementList();
OmmArray array = EmaFactory.createOmmArray();                           


array.add(EmaFactory.createOmmArrayEntry().ascii("TRI.N"));
array.add(EmaFactory.createOmmArrayEntry().ascii("IBM.N"));

batch.add(EmaFactory.createElementEntry().array(EmaRdm.ENAME_BATCH_ITEM_LIST,
array));
consumer.registerClient(EmaFactory.createReqMsg().serviceName("DIRECT_FEED").payload(batch),
appClient);

For the complete application source code shipped with Elektron Java SDK package, it is <Elektron Java SDK
package>\Ema\Src\examples\java\com\thomsonreuters\ema\examples\training\consumer\series300\example370__MarketPrice__Batch.

A snipped
source code in EMA C++:

UInt64 handle = consumer.registerClient( ReqMsg().serviceName( "DIRECT_FEED" ).payload( ElementList().addArray( ENAME_BATCH_ITEM_LIST, OmmArray().addAscii( "TRI.N" ).addAscii( "IBM.N" ).complete() ).complete() ), client );

For the complete application source code shipped with Elektron C++ SDK package, it is

<Elektron C++ SDK
package>\Ema\Examples\Training\Consumer\300_Series_Examples\370__MarketPrice__Batch

Nipat Kunvutipongsak

@priyanka.mundargi, EMA doesn't support that comma separated items because OMMConsumer threats a name value of a ReqMsg object as an individual single item. So, you should use a loop to help explicitly iterate calling the registerClient() method for each item.

For example:

// Single item call
ReqMsg reqMsg = EmaFactory.createReqMsg();
consumer.registerClient(reqMsg.domainType(EmaRdm.MMT_MARKET_PRICE).serviceName("DIRECT_FEED").name("JPY="), client);

// Multiple items call
String[] items = {"JPY=", "THB=", "EUR="};

ReqMsg reqMsg = EmaFactory.createReqMsg();
for (String item:items) {
    consumer.registerClient(reqMsg.clear().reqMsg.domainType(EmaRdm.MMT_MARKET_PRICE).serviceName("DIRECT_FEED").name(item), client);
}

Hope this helps.

priyanka.mundargi

Am getting below in logs "state="Closed / Suspect / None / 'Login stream was closed.'

What if i need continous data?

pimchaya.wongrukun01

Hello @priyanka.mundargi

What EMA edition that you are using? Is it C++ or Java?

Did the log above was shown after the application received data?

priyanka.mundargi

Yes. that is right.

priyanka.mundargi

Why are we reading Symbol as Ascii?is it always ascii?using array.add(EmaFactory.createOmmArrayEntry().ascii("TRI.N"));

pimchaya.wongrukun01

Hello @priyanka.mundargi

The "state="Closed / Suspect / None / 'Login
stream was closed.' is shown when consumer.uninitialize(); is called after 60,000 milliseconds/60 seconds. According to the EMA Java example source code in example370__MarketPrice__Batch:

consumer.uninitialize() is to close the login stream(log out) that's why you see this state.

To continue receiving data, just change 60000 millisecond in
Thread.sleep(60000); to be your favorite time.

pimchaya.wongrukun01

Hello @priyanka.mundargi

If you have a new question, please post it to be a new one in the

https://community.developers.refinitiv.com/questions/ask.html

This will allow everyone can see your question obviously and can post the answer to help you.

pimchaya.wongrukun01

Hello @priyanka.mundargi

This is the specification of batch request that the ItemList must be an array of ASCII as shown in <Elektron Java SDK package>\Ema\Docs\EMAJ_RDMUsageGuide.pdf at section A.2 ItemList: