Scout/Proposals/InputValidation

There have been several issues about the current concepts and implementation of the scout input validation. This page describes the status quo, problems and possible solutions.

Comments

• Validation is done on focus lost or on any key input (getConfiguredValidateOnAnyKey())

Documentation & Discussions

ValueField#Events

Forum

[1] Summary of problems

• IFormField.getValue() always returns the last valid value and not the displayed value. IFormField.getErrorStatus returns an error, if there is one, but error value

-> Depending on your use case you might need to check the error status before reading the value -> execChangedValue not firing if an invalid value is reverted back to the previous value

• Invalid value set programmatically

-> Because the framework worka with the assumption that only valid values are set in the scout model layer, the framework is acting wired when a wrong value is set. The invalid value is not shown in the GUI, only the error. ErrorStatus and displaytext are inconsistent

• API

- SmartField.execvalidatevalue cannot be used - Update the value of a field during its own execChangedValue() event. - Controlling if execChangedValue() is called or not.

[2] Disable OK Button on error

If there is at least one field having errorStatus with severity equals to ERROR, then the Button OK will be disabled. -> The "Scout way" is to leave the OK button enabled all the time and rather present a error message to the user when he clicks it.

[3] Limiting input in FormFields, e.g.

• suppression of non-numeric input in number fields
• suppression of digits in string fields
• limiting the number of characters that can be entered in a field

[4] SmartField.execvalidatevalue cannot be used

SmartField.execvalidatevalue is final

[5] Not possible to mix execValidateValue and execChangedValue

Bugzilla

https://bugs.eclipse.org/bugs/show_bug.cgi?id=419693