returnBlankAsNull for AbstractValueWidget

[jzaruba]

Hello

I need MaterialTextBox to return null instead of blank value. So I extended it like this:

public class MaterialTextBox extends gwt.material.design.client.ui.MaterialTextBox {
        /**
         * If true #getValue will return null when the value is blank
         */
	private boolean returnBlankAsNull = false;

	public boolean isReturnBlankAsNull() {
		return this.returnBlankAsNull;
	}

	public void setReturnBlankAsNull(boolean returnBlankAsNull) {
		this.returnBlankAsNull = returnBlankAsNull;
	}

	@Override
	public String getValue() {
		if(isReturnBlankAsNull() && isBlank()) {
			return null;
		}
		return super.getValue();
	}

	protected boolean isBlank() {
		return !createBlankValidator().isValid(super.getValue());
	}
}

I have added the new attribute to MaterialTextBox but I believe it should eventually go to gwt.material.design.client.base.AbstractValueWidget.

Would you consider accepting this modification i.e. a pull request?

[jzaruba]

Typical use-case would be non-mandatory inputs/fields with @Pattern constraint, like e-mail or phone number. In such cases the POJO you get from the editor will have "" in its String fields, and validation will test @Pattern.regexp against "", which usually fails.
While there are other solutions to the situation (a pipe in your regexp, preprocessing your POJO, ...), personally I like the null-approach the best.

[BenDol]

This would be acceptable, however note that there are edge cases in classes like MaterialValueBox where the getValue is accessing its value from the valueBoxBase. So you will have to perform the check there also (at least until that class is rewritten).

[BenDol]

In fact you will have to make sure all the classes extending MaterialValueBox call super.getValue() before accessing the value for real and handle it appropriately. I would be okay reviewing a PR if you want to submit one. Thanks!

[jzaruba]

Which branch should the changes go to please?

[BenDol]

release_2.1

[jzaruba]

In the end it seems MaterialValueBox is actually the best place to implement the change.

[kevzlou7979]

Agreed this can be used also not only in MaterialTextBox but also all widget extending ValueBox

[kevzlou7979]

I'm writing now the Documentation on the Latest 2.1 demo snapshot and also A JUnit test for this.

[kevzlou7979]

Demo Added

JUnit Added
3a938d1