Change the name of
.samplemethod to
.convert and edit it like
this:
method ModifyData.convert (pt1, !pt2, multiplier, adder)
{
local output;
set(pt2, ((pt1 * multiplier) + adder));
princ(format("The sine is: %2.3f Converted it is: %2.3f\n",
pt1, eval(pt2)));
}
This method does the conversion and prints the
output. Notice that the
pt2 argument
has an exclamation point (
!) in front
of it. This protects the argument from being evaluated,
because we only want the point name, not its value.
Please refer to
Function Arguments
in the Gamma manual for more information.
We need to assign a value to the point, but keep
the variable name associated with the DataHub point, not the
value. This requires the
set
function, because using the equals sign would just assign
the value to the variable, and it would never reach the
DataHub point.
Edit the .constructor
method to look like this:
method ModifyData.constructor ()
{
multiplier = 3;
adder = 5;
if (undefined_p($default:ConvertedSine))
datahub_command ("(cset default:ConvertedSine \"\")", 1);
.OnChange(#$DataSim:Sine,
`(@self).convert($DataSim:Sine,
$default:ConvertedSine, multiplier, adder));
after(3, `destroy(@self));
}We don't make the
multiplier and
adder variables local because they'll
be used by the
Application
class's .destructor method. We
use the
datahub_command
function call the
cset function to
have the DataHub create the
ConvertedSine
point and set its value to an empty string. We then use
the inherited
.OnChange method to
set up the
.convert method.
