New Data Dictionary interface in EMA C++

@Akechi Sato

There are several improvements in EMA 3.1.0. In term of Data Dictionary, I found new classes from EMA Reference Manual (<EMA Install Folder>\Docs\refman\ema). You should be able to use below classes to access EMA data dictionary

• DataDictionary (thomsonreuters::ema::rdm)
• DictionaryEntry (thomsonreuters::ema::rdm)
• DictionaryUtility (thomsonreuters::ema::rdm)

Also in this version, FieldEntry class provide method to get Enum display by using getEnumDisplay() method.

The new version implements features which allow you to get access to the internal EMA dictionary via the thomsonreuters::ema::rdm::DataDictioanry class. The EMA’s DataDictionary is the Dictionary utility which provides the same capability as same as the RsslDataDictionary in ETA C. The example "332__Dictionary__Streaming" also update to use the class to decode downloaded Data Dictionary.

Moreover application can extract a DataDictionary object used by FieldList when decoding it via the DictionaryUtility::dataDictionary() static method. But The DataDictionary is valid only in the context of a callback method according to EMA Reference Manual.

DataDictionary and DictionaryEntry class also provide interfaces to get Dictionary information such as EnumTables, DictionaryID, FieldVersion, EnumRecordTemplateVersion.

Below is snippet of codes I used to access Dictionary data such as Fid ID, Fid Acronym and print Enum table in case that the Fid is Enumerate field. I have tested the codes with 332_Dictionary_Streaming example and change codes in AppClient::decode to print dictionary after it received both RWFFld and RWFEnum dictionary.

if (fldDictComplete && enumTypeComplete)
{
    const EmaVector<DictionaryEntry>& dictEntries =
dataDictionary.getEntries();
    for (int index=0; index < dictEntries.size(); index++)
    { 
               int fidID = dictEntries[index].getFid();
               std::cout<< "FID[" << fidID << "][" <<
dictEntries[index].getAcronym() << "]" << endl;

               if(dictEntries[index].hasEnumTypeTable())
               {
                   const EnumTypeTable& enumTable = dictEntries[index].getEnumTypeTable();
		   const EmaVector<EnumType>& enumType = enumTable.getEnumTypes();
                   for(int i = 0; i < enumType.size(); i++)
                   {
		      EmaString displayTxt;
                      displayTxt.append(enumType[i].getDisplay());
                      cout<< "\t Enum [" << enumType[i].getValue() << "]
Display[" << displayTxt << "]" << endl;
                    }
               }
     }
}

And below is output when running the example with modified codes

…


FID[12][HIGH_1]
FID[13][LOW_1]
FID[14][PRCTCK_1]
                Enum [0] Display[ ]
                Enum [1] Display[Þ]
                Enum [2] Display[þ]
                Enum [3] Display[ ]
                Enum [4] Display[0]
                Enum [5] Display[U]
                Enum [6] Display[D]
                Enum [7] Display[+]
                Enum [8] Display[-]
FID[15][CURRENCY]
                Enum [0] Display[   ]
                Enum [4] Display[AFA]
                Enum [8] Display[ALL]
                Enum [12] Display[DZD]
                Enum [20] Display[ADP]
                Enum [24] Display[AON]
                Enum [32] Display[ARS]
                Enum [36] Display[AUD]
                Enum [37] Display[AUc]
                Enum [40] Display[ATS]
                Enum [44] Display[BSD]
                Enum [48] Display[BHD]
                Enum [50] Display[BDT]
                Enum [51] Display[AMD]
                Enum [52] Display[BBD]
                Enum [56] Display[BEF]
                Enum [60] Display[BMD]
                Enum [64] Display[BTN]
                Enum [68] Display[BOB]
                Enum [70] Display[BAD]
                Enum [72] Display[BWP]
                Enum [76] Display[BRL]
...