Question

I have a component,where users can choose to set any date at all even null, but when the date is not null, it should render a panel to allow for other options. But, the date is not getting updated and is always null as a result it never renders the panel. Help needed on this. Below is my code:

        <p:calendar id="dt"
                    value="#{user.deadline}"
                    pattern="MM/dd/yyyy"                        
                    showOn="button"
                    mindate="#{userr.minDate}">
            <f:validator validatorId = "dateValidator"/>
            <f:attribute name="minDate" value="#{user.minDate}" />

            <p:ajax event="dateSelect" listener="#{user.updateDeadlineDate}" update=":userForm:userReminderForm"/>
        </p:calendar>

        <p:panel id= "myPanel" rendered="#{user.getDeadline != null}">
         .. some component that needs user.deadline

        </p:panel>

snippet from my bean:

   public Date getDeadline() {
    return deadline;
     }

public void setDeadline(Date deadline) {
    this.deadline=deadline;
      }
 public void updateDeadlineDate(DateSelectEvent event) {

    this.setDeadline(event.getDate());

}

Answer 1

First, your update target is probably wrong (nested forms :userForm:userReminderForm are invalid in HTML/JSF), maybe you wanted to do update=":userForm" (since you can’t update the panel directly as siebz0r pointed out):

<p:ajax event="dateSelect" listener="#{user.updateDeadlineDate}" update=":userForm"/>

<p:panel id= "myPanel" rendered="#{user.deadline != null}">
     .. some component that needs user.deadline

</p:panel>

The getDeadline is unnecessary, when you reference backing bean properties just use their names like deadline.

Note that you can use the validator of the calendar component, so you can avoid the additional <f:validator validatorId = "dateValidator"/> tag.

Your <f:attribute name="minDate" value="#{user.minDate}" /> tag is probably unnecessary in this case. If you want to set your deadline to the value of minDate (since they are in the same bean) just do:

public void updateDeadlineDate(DateSelectEvent event) {
    mindDate = event.getDate()
    this.setDeadline(mindDate);
}

and remove the <f:attribute name="minDate" value="#{user.minDate}" />.

Finally I would use the empty keyword in the rendered attribute instead of != null: rendered="#{not empty user.deadline}"