JSF2跨字段验证失败循环

Question

Requirements in an app I'm developing say that when performing a search, the user should not be able to search for City without entering State, and vice versa, they shouldn't be able to search for State without entering City.

search.xhtml

<h:inputText id="city" binding="#{city}" value="#{search.city}" validator="#{search.validateCity}">
  <f:attribute name="state" value="#{state}"/>
</h:inputText>

<h:inputText id="state" binding="#{state}" value="#{search.state}" validator="#{search.validateState}">
  <f:attribute name="city" value="#{city}"/>
</h:inputText>

Search.java

public void validateCity(FacesContext context, UIComponent component, Object convertedValue) {
    UIInput stateComponent = (UIInput) component.getAttributes().get("state");
    String state = (String) stateComponent.getValue();
    if(convertedValue.toString().length() > 0) {
        if(state.length() < 1) {
            throw new ValidatorException(new FacesMessage("Please enter State."));
        }
    }
}

public void validateState(FacesContext context, UIComponent component, Object convertedValue) {
    UIInput cityComponent = (UIInput) component.getAttributes().get("city");
    String city = (String) cityComponent.getValue();
    if(convertedValue.toString().length() > 0) {
        if(city.length() < 1) {
            throw new ValidatorException(new FacesMessage("Please enter City."));
        }
    }
}

I've simplified down my code to show what I attempted with the standard cross field validation method. However, the problem I'm hitting is that in the validation phase, both City and State are showing Validation errors, I'm guessing because the two validators are getting in each others' way and therefore creating a loop of failure.

Is there a workaround I can use to get around this?

Thanks.

Answer 1

The components are validated in the order as they are declared in the component tree.

When you call UIInput#getValue() on a component which isn't validated yet, then it'll return null . Also, when you call UIInput#getValue() on a component which is already validated and been marked invalid, then it'll return null (or the old model value).

If you want to get the value of the second component during validation of the first component, then you should be using UIInput#getSubmittedValue() instead of UIInput#getValue() . You should only keep in mind that this returns the unconverted String .

Alternatively, you could take a look at OmniFaces <o:validateAllOrNone> component.

<h:inputText id="city" value="#{search.city}" />
<h:inputText id="state" value="#{search.state}" />
<o:validateAllOrNone id="cityAndState" components="city state" message="Please fill both city and state." />
<h:message for="cityAndState" />