Question

When the Save button is pressed, the data from the actionsDialog should be validated. If the required information is entered and valid, a second dialog called reasonDialog would be displayed.

Non-JSF validation of the saved object is done with a method that returns a list of error messages. I case the validation fails the errors messages are displayed with FacesMessage. How should I do in objectsBean.validate to trigger the if else clause from oncomplete?

<p:dialog id="actionsDialog" widgetVar="actionsDialog" dynamic="true" 
    resizable="false" width="800" modal="true">
    <ui:include src="/WEB-INF/flows/custom-flow/genericObject.xhtml"/>
    <f:facet name="footer">
        <p:commandButton value="Save" update="msgs"
            oncomplete="if (args.validationFailed) {reasonDialog.hide()} else {reasonDialog.show()}"
            actionListener="#{objectsBean.validate}"/>
        <p:commandButton value="Cancel" immediate="true" oncomplete="actionsDialog.hide()" />
    </f:facet>
</p:dialog>

Answer 1

If utilizing the JSF-builtin validation facility (i.e. just use validators which throw ValidatorException the usual way with therein the desired faces message) is really not an option for some reason (I’d really think twice, no, thrice about working around JSF validation facility), then you can always use FacesContext#validationFailed() to signal JSF that the validation has failed in general, which is exactly what JSF validation facility is doing under the covers when a ValidatorException is caught.

FacesContext.getCurrentInstance().validationFailed();