How to validate if at least one of multiple input fields is entered?

Question

I have a form with 3 fields, and submit button. when button clicked, if none is entered in 3 fields, throw validation message. If any one of the 3 fields are entered process

Answer 1

At least for iceFaces another approach to validate across multiple fields, especially when the validation is more complex than just "required", is to use application level validation inside your backing bean.

@see Custom Validator in Backing Beans

• Add the validator attribute to you rcomponent and point it to teh validation method in your backing bean
• inside teh backing bean you can now access all form fields and do cross validation

Regards

Rob

Answer 2

Just let the required attribute of each field check the presence of the submitted value of the other fields. The submitted value is available in the parameter map #{param} by the client ID as key.

Here's a kickoff example:

<h:form id="form">
    <h:inputText id="field1" ... required="#{empty param['form:field2'] and empty param['form:field3']}" />
    <h:inputText id="field2" ... required="#{empty param['form:field1'] and empty param['form:field3']}" />
    <h:inputText id="field3" ... required="#{empty param['form:field1'] and empty param['form:field2']}" />
</h:form>

It gets only more ugly as the amount of fields grows.

Alternatively, you can use OmniFaces <o:validateOneOrMore>:

<h:form id="form">
    <h:inputText id="field1" ... />
    <h:inputText id="field2" ... />
    <h:inputText id="field3" ... />

    <o:validateOneOrMore id="oneOrMore" components="field1 field2 field3" />
    <h:message for="oneOrMore" />
</h:form>

Please note that performing validation in action method is bad design. You should use the standard JSF validation facilities for this such as requiered, validator, <f:validator> and/or <f:validateXxx>.