Union data structure and Python data

Hi Gianpiero, many thanks for your reply... I still cannot get the solution to work.. when I use the getString with (#) i get an error 

edwards@edwards-VirtualBox /media/sf_shared_drive_VM/Test/examples/python/Monitor $ python monitor_reader.py
DDS_DynamicData_bind_typeI:type not supported (primitive or string not allowed as a top-level type)
DDS_DynamicData_autoBindAndExecuteOperation:invalid operation, bound to member id 3
DDS_DynamicData_autoBindAndExecuteOperation:field valueLong# (id=3) not found
DDS_DynamicData_unbind_complex_member:internal error 1 trying to to stream
DDS_DynamicData_autoBindAndExecuteOperation:internal error trying to DDS_DynamicData_unbind_complex_member
DDS_DynamicData_finalize:WARNING: destructing object bound to a member, automatically unbinding now
DDS_DynamicData_unbind_complex_member:internal error 1 trying to to stream
RTILuaDynamicData_get:!get kind failed for 'parameterValue.valueLong#'
DDS_DynamicData_bind_complex_member:invalid operation, bound to member id 7
DDS_DynamicData_autoBindAndExecuteOperation:invalid operation, bound to member id 4

also my xml is slightly different in that when i use the api setNumber i only pass in 

vBool  = output.instance.setBoolean("parameterValue.valueBool", False);

disc = input.samples.getString(j, "parameterValue.valueLong#");

lData= input.samples.getNumber(j, "parameterValue.valueLong");

this is the xml here:

<module name="ParameterModule">
<enum name="DDS_UNION_E">
<enumerator name="UNION_BOOL" value="0"/>
<enumerator name="UNION_TEXT" value="1"/>
<enumerator name="UNION_UNUSED" value="2"/>
<enumerator name="UNION_LONG" value="3"/>
<enumerator name="UNION_DOUBLE" value="4"/>
</enum>
<enum name="TYPE_E">
<enumerator name="TEMPERATURE" value="0"/>
<enumerator name="FLOW" value="1"/>
<enumerator name="POSITIVE_PRESSURE" value="2"/>
<enumerator name="NEGATIVE_PRESSURE" value="3"/>
<enumerator name="CURRENT" value="4"/>
<enumerator name="VOLTAGE" value="5"/>
<enumerator name="SPEED" value="6"/>
<enumerator name="EDW_BOOL" value="7"/>
<enumerator name="DISTANCE" value="8"/>
<enumerator name="PERCENT" value="9"/>
<enumerator name="NUMBER" value="10"/>
<enumerator name="TEXT" value="11"/>
<enumerator name="DURATION" value="12"/>
<enumerator name="PARAM_UNUSED" value="13"/>
<enumerator name="COUNTER" value="14"/>
</enum>
<union name="DATA_T" topLevel="false">
<discriminator type="nonBasic" nonBasicTypeName="ParameterModule::DDS_UNION_E"/>
<case>
<caseDiscriminator value="(ParameterModule::UNION_BOOL)"/>
<member name="valueBool" id="1" type="boolean"/>
</case>
<case>
<caseDiscriminator value="(ParameterModule::UNION_TEXT)"/>
<member name="valueStr" id="2" stringMaxLength="S3DDSDefaults::NAME_LENGTH" type="string"/>
</case>
<case>
<caseDiscriminator value="(ParameterModule::UNION_UNUSED)"/>
<member name="unused" id="3" type="boolean"/>
</case>
<case>
<caseDiscriminator value="(ParameterModule::UNION_LONG)"/>
<member name="valueLong" id="4" type="long"/>
</case>
<case>
<caseDiscriminator value="(ParameterModule::UNION_DOUBLE)"/>
<member name="valueDbl" id="5" type="double"/>
</case>
</union>
<struct name= "AttributeData" topLevel="false">
<member name="attributeName" stringMaxLength="S3DDSDefaults::SHORT_NAME_LENGTH" type="string"/>
<member name="attributeNameResourceId" type="unsignedLong"/>
<member name="attrType" type="nonBasic" nonBasicTypeName= "ParameterModule::TYPE_E"/>
<member name="value" type="nonBasic" nonBasicTypeName= "ParameterModule::DATA_T"/>
<member name="changed" type="boolean"/>
</struct>
<typedef name="attributeList" sequenceMaxLength="S3DDSDefaults::SEQUENCE_LENGTH" type="nonBasic" nonBasicTypeName= "ParameterModule::AttributeData"/>
<struct name= "DataType">
<member name="time_sec" type="long"/>
<member name="time_usec" type="unsignedLong"/>
<member name="objectId" stringMaxLength="S3DDSDefaults::NAME_LENGTH" type="string" key="true"/>
<member name="parameterName" stringMaxLength="S3DDSDefaults::SHORT_NAME_LENGTH" type="string"/>
<member name="parameterNameResourceId" type="unsignedLong"/>
<member name="parameterType" type="nonBasic" nonBasicTypeName= "ParameterModule::TYPE_E"/>
<member name="parameterValue" type="nonBasic" nonBasicTypeName= "ParameterModule::DATA_T"/>
<member name="attributes" type="nonBasic" nonBasicTypeName= "ParameterModule::attributeList"/>
</struct>

best regards,

Nick

Hi Gianpiero, 

I've found out the best solution to this which works for me is to use dictionarys.  

to write i set a dictionary then write the dictionary with the values in it i want to set..

dic = dict(parameterType=0, objectId= "testID",
changed=False,
time_sec=10,
time_usec=20,
parameterName="gasflowrate",
parameterNameResourceId=10,
parameterValue=dict(unused=True))

output.instance.setDictionary(dic);
output.write();

then I read the dictionary in its entirity

sample = input.samples.getDictionary(j)

print(sample);

or if i want to access a particular value in the dictionary to do an assert on it i will convert to JSON first

dic = rtiInputFixture.samples.getDictionary(1)
json_dic = json.dumps(dic)
loaded_dic=json.loads(json_dic)

parameterValue=loaded_dic['parameterValue']

then do assert parameterValue== testMsg['parameterValue'] 

this gets the result I want.. 

I tried to use the method you suggest but with no luck.. has anyone used this method with success?? 

very best regards,

Nick

Hi Gianpiero,  thank you very much for your help so far.. we are having some consultation time with your colleague Juanjo.  he was explaining the request reply api to me.. and gave me the C++ code for request reply.  I would like to repeat this in Python now.. I think the part of code I am missing in Python would be this section in C++.. 

/* Important: We create a CFT with a filter on the
metadata. In this case, we expect to receive
samples that contain the writer_guid of our writer
in the related_sample_identity. The replier is in
charge of setting that field correctly when
receiving the request. */
DDS_DataWriterQos qos;
Request_writer->get_qos(qos);
std::ostringstream filter_str(std::ostringstream::out);
filter_str << "@related_sample_identity.writer_guid.value" << " = &hex(";
for (int i = 0; i < 16; i++) {
if (qos.protocol.virtual_guid.value[i] < 0x10) {
filter_str << "0";
}
filter_str << std::hex << (int)qos.protocol.virtual_guid.value[i];
}
filter_str << ")";
printf("Using filter: '%s'\n", filter_str.str().c_str());
DDSContentFilteredTopic * reply_cft =
participant->create_contentfilteredtopic(
"Reply CFT Topic", reply_topic,
filter_str.str().c_str(), DDS_StringSeq());
if (reply_cft == NULL) {
printf("create_contentfilteredtopic error\n");
method_shutdown(participant);
return -1;

Have you an idea how I could covert this into Python so that I can use this in my Python request reply app.. ?

would it be easier if I e-mailed you directly possibly? if you supplied your e-mail address.. 

many thanks,

Nick