Error Handling
User Input Validations
Where appropriate, the user interface is designed with javascript and occasionally using server-side input validations to ensure that the answer submitted by the user is valid. There are two main types of javascript validations, the first prevents non-valid characters from being typed into text boxes (e.g. alphabetic characters not allowed in an integer text field), while the second checks the final value against the allowable range (e.g. percentage values must be between 0% and 100%). Additionally in a few instances, there are server side validations that check inputs for more complicated problems (e.g. window area is greater than wall area when framing members and area of doors is included). When an error is noted, a message is displayed to the user, identifying the problem and asking them to correct their inputs.
Failures in the DOE-2.1 Calculation
On occasion, a dropped network connection or an inappropriate house description can cause the DOE-2 engine to experience failure. The Home Energy Saver has error traps in place to prevent the loss of data in a situation where there is a DOE-2 failure. After the results of the DOE-2 run are returned to the web application, the returned energy consumptions are tested for valid values. If an error is detected, the web application discards the returned values, continuing the calculation with the previous energy consumptions for heating and cooling. If results are not returned from DOE, the application again reverts to previously stored data.