id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
6331	[NF] Assigning parameters by external functions	spinhalf@…	Per Östlund	"By the pull request by Perost, the external functions are now able to assign values to parameters ""[https://github.com/OpenModelica/OpenModelica/pull/210]"".
Overall, it works well.
However, the arrays of parameter (record) never work!
In the following example, the model ""test5"" shows such a problem with  myParamsArray and myParamsArray2; actually extracting the elements are not possible giving some errors in the compilation. 

This investigation is motivated from an attempt to fix the ""ExternalMedia"" library; the constant (fluidConstants) inherited by Modelica.Media is assigned by some external functions, which gives rise to a trouble relevant to the issue of NFEvalFunction.evaluateExternal (https://trac.openmodelica.org/OpenModelica/ticket/5240).
I'm just trying to circumvent the error by replace the constant ""externalFluidConstants"" with a parameter of the same contents as a temporary remedy. However, the final replacement of fluidConstants should be an array with 1 element. So I get stuck; this is the same matter of the previous struggle with the old front end, when I abandoned fluidConstants using externalFluidConstants instead..

{{{
package TestEvalExt
  record MyRecord ""a record whose members are assigned by an external function""
    Real p1 = extfunc1(), p2 = 2. * extfunc1();
  end MyRecord;

  parameter MyRecord myParams(p1 = 0.1 * extfunc1(), p2 = extfunc1());
  parameter MyRecord[1] myParamsArray = {myParams};
  parameter MyRecord[1] myParamsArray2;

  model test1 ""initialzing a constant by an external function (NOT WORKING!)""
    constant MyRecord params(p1 = 0.1 * extfunc1(), p2 = extfunc1());
    //<-- it's a constant assigned by an external function..
  end test1;

  model test2 ""initialzing a parameter by an external function (WORKING!)""
    parameter MyRecord params(p1 = 0.1 * extfunc1(), p2 = extfunc1());
    //<-- it's a parameter assigned by an external function..
  end test2;

  model test3 ""initialzing a parameter and an array (WORKING!)""
    parameter MyRecord params(p1 = 0.1 * extfunc1(), p2 = extfunc1());
    // <-- a parameter
    parameter MyRecord[2] params_array = {params, params};
    // <-- a array of the parameter
  end test3;

  model test4 ""getting a subelement from the initialized parameter (WORKING!)""
    extends test3;
    parameter Real p1 = params_array[2].p1;
    //from an inherited array
    parameter Real p2 = myParams.p2;
    //from a parameter in the package (initialized outside..)
  end test4;

  model test5 ""getting a subelement from the parameter array (NOT WORKING!)""
    extends test3;
    parameter Real p2 = myParamsArray[1].p2;
    // <-- from an array of paramater of the package (initialized outside..)
    parameter Real p2 = myParamsArray2[1].p2;
    // <-- it doesn't work too..
  end test5;

  function extfunc1
    output Real ret;
  
    external ""C""  annotation(
      Include = ""
        double extfunc1(void){
            return 1.234;
         }
       "");
  end extfunc1;
end TestEvalExt;
}}}
"	defect	closed	high	NeedsInput	New Instantiation	1.16.0	fixed	NONSTRUCTURAL_PARAMETER