Quasar implementation of UaVariant CacheVariables prevent writing array from client

[xaxis-ii]

The default generated AddressSpace implementation of UaVariant-type CacheVariables prevents clients from writing back arrays matching the current datatype, since the valueRank is always set to -1 for non-array types (including UaVariant), despite the server being allowed/able to write in an array-type variant value.

A suggested fix would be setting the valueRank for UaVariant CacheVariables to -3 (which in the open62541 implementation corresponds to scalar or 1D-array; see open62541 docs - Information Modelling) when generating the AddressSpace class. A possible implementation would be the addition of the following two lines to AddressSpace/templates/designToClassBody.jinja:

141         {# configure valueRank and arrayDimensions #}
142         {% if cv.array|length>0 %}
143           m_{{cv.get('name')}}->setValueRank( 1 ); // 1D-array
144           {
145             UaUInt32Array arrayDimensions;
146             arrayDimensions.create(1);
147             m_{{cv.get('name')}}->setArrayDimensions(arrayDimensions);
148           }
149 +       {% elif cv.get('dataType') == 'UaVariant' %}
150 +         m_{{cv.get('name')}}->setValueRank( -3 ); // scalar or 1D-array
151         {% else %}
152           m_{{cv.get('name')}}->setValueRank( -1 ); // scalar
153         {% endif %}