/// <summary>
/// Builds the expression decision definition
/// </summary>
/// <returns>Decision definition built</returns>
/// <exception cref="DmnBuilderException">Throws <see cref="DmnBuilderException"/> when the definition has already been built</exception>
/// <exception cref="DmnBuilderException">Throws <see cref="DmnBuilderException"/> when the expression or output variable is not defined in builder</exception>
protected internal override IDmnDecision Build()
{
if (IsBuilt)
{
throw Logger.Error <DmnBuilderException>("Decision is already built");
}
if (OutputVariableInternal == null)
{
throw Logger.Error <DmnBuilderException>($"Missing output variable for expression decision {Name}");
}
if (string.IsNullOrWhiteSpace(Expression))
{
throw Logger.Error <DmnBuilderException>($"Missing expression for expression decision {Name}");
}
//create
var expressionDecision = new DmnExpressionDecision(
Name,
Expression,
OutputVariableInternal.GetResultOrBuild(),
RequiredInputs.Select(i => Variables[i].GetResultOrBuild()).ToArray(),
RequiredDecisions.Select(d => Decisions[d].GetResultOrBuild()).ToArray());
ResultInternal = expressionDecision;
return(expressionDecision);
}
/// <summary>
/// Sets the output variable to store the result of the decision expression evaluation to
/// </summary>
/// <param name="variable">Reference to the variable used to store the expression decision output</param>
/// <exception cref="DmnBuilderException">Throws <see cref="DmnBuilderException"/> when the definition has already been built</exception>
/// <exception cref="ArgumentNullException">When the <paramref name="variable"/> is null</exception>
/// <exception cref="DmnBuilderException">Throws <see cref="DmnBuilderException"/> when the <paramref name="variable"/> can't be found in <see cref="VariableCatalog"/></exception>
private void SetOutput(Variable.Ref variable)
{
if (IsBuilt)
{
throw Logger.Error <DmnBuilderException>("Decision is already built");
}
if (variable == null)
{
throw new ArgumentNullException(nameof(variable));
}
OutputVariableInternal =
Variables[variable]
?? throw Logger.Error <DmnBuilderException>($"Can't get the variable from reference {variable.Name}");
OutputVariableInternal.AddValueSetter($"Expression Decision {Name}");
}
