Example for Sateful input field which syncs the value state to the server on change value event.

StatefulInput.java

import com.webfirmframework.wffweb.tag.html.AbstractHtml;
import com.webfirmframework.wffweb.tag.html.attribute.AttributeNameConstants;
import com.webfirmframework.wffweb.tag.html.attribute.Value;
import com.webfirmframework.wffweb.tag.html.attribute.core.AbstractAttribute;
import com.webfirmframework.wffweb.tag.html.attribute.event.form.OnChange;
import com.webfirmframework.wffweb.tag.html.formsandinputs.Input;

public class StatefulInput extends Input {

    public StatefulInput(AbstractHtml base, AbstractAttribute... attributes) {
        super(base, attributes);
        develop();
    }

    private void develop() {

        if (super.getAttributeByName(AttributeNameConstants.ONCHANGE) != null) {
            throw new IllegalArgumentException("OnChange attribute should not be explicitly given in this tag.");
        }

        final Value valueAttr;
        {
            Value value = (Value) super.getAttributeByName(AttributeNameConstants.VALUE);
            valueAttr = value != null ? value : new Value("");
        }

        OnChange onChange = new OnChange("return true;",
                (bm, ev) -> {
                    String value = (String) bm.getValue("attrValue");
                    //updateClient must be false to avoid synching the changes to the client browser page
                    valueAttr.setValue(false, value);
                    return null;
                },
                "return {attrValue: source.value};", null);


        super.addAttributes(valueAttr, onChange);
    }
}

Usage:- new StatefulInput(this, new Type(Type.TEXT), new Name("First Name"));

Developers guide to get started

Convert HTML5 to webfirmframework Java/Kotlin Code