saChange method
The standard change handler to change a sym
value in the SamHot table.
This is used by widget handlers to change values within the model.
It turns on the render request for the action so that the new value can be reflected.
Note This is used by widgets such as TextField that have already updated the display. The render does not cause a new widget build cycle unless the state changes.
Implementation
void saChange(SamModel sm,SamReq req) {
//log("sa-change called sym=${req.stepParms.containsKey('actMap')}");
String sym = req.stepParms['actMap']['sym'];
var val = req.stepParms['actMap']['value'];
if(_bDebLog)log("sa-change called sym=$sym val=$val");
sm.setHot(sym,val);
req.render = true;
}