protected Expression GetConstantExp(MetadataBase metadata)
{
PropertyInfo propInfo = metadata.GetProperty(PropertyName);
if (propInfo == null)
{
throw new Exception($"Property {PropertyName} not found in metadata");
}
if (propInfo.PropertyType == typeof(string))
{
return(Expression.Constant(Value));
}
else if (propInfo.PropertyType == typeof(int))
{
if (!int.TryParse(Value, out int intValue))
{
throw new Exception($"Unable to cast {Value} to int");
}
return(Expression.Constant(intValue));
}
else if (propInfo.PropertyType == typeof(float))
{
if (!float.TryParse(Value, out float floatValue))
{
throw new Exception($"Unable to cast {Value} to float");
}
return(Expression.Constant(floatValue));
}
else if (propInfo.PropertyType == typeof(double))
{
if (!double.TryParse(Value, out double doubleValue))
{
throw new Exception($"Unable to cast {Value} to double");
}
return(Expression.Constant(doubleValue));
}
else if (propInfo.PropertyType == typeof(decimal))
{
if (!decimal.TryParse(Value, out decimal decimalValue))
{
throw new Exception($"Unable to cast {Value} to decimal");
}
return(Expression.Constant(decimalValue));
}
else if (propInfo.PropertyType == typeof(int?))
{
if (Value == null)
{
return(Expression.Constant(null, typeof(int?)));
}
if (!int.TryParse(Value, out int intValue))
{
throw new Exception($"Unable to cast {Value} to int");
}
return(Expression.Constant(new int?(intValue), typeof(int?)));
}
else if (propInfo.PropertyType == typeof(float?))
{
if (Value == null)
{
return(Expression.Constant(null, typeof(float?)));
}
if (!float.TryParse(Value, out float floatValue))
{
throw new Exception($"Unable to cast {Value} to float");
}
return(Expression.Constant(new float?(floatValue), typeof(float?)));
}
else if (propInfo.PropertyType == typeof(double?))
{
if (Value == null)
{
return(Expression.Constant(null, typeof(double?)));
}
if (!double.TryParse(Value, out double doubleValue))
{
throw new Exception($"Unable to cast {Value} to double");
}
return(Expression.Constant(new double?(doubleValue), typeof(double?)));
}
else if (propInfo.PropertyType == typeof(decimal?))
{
if (Value == null)
{
return(Expression.Constant(null, typeof(decimal?)));
}
if (!decimal.TryParse(Value, out decimal decimalValue))
{
throw new Exception($"Unable to cast {Value} to decimal");
}
return(Expression.Constant(new decimal?(decimalValue), typeof(decimal?)));
}
throw new Exception($"GetConstantExp: type {propInfo.PropertyType.FullName} not supported");
}