支持Bean无法获取javascript发送的值

Question

I have three drop down lists whose values are been copied to <h:inputHidden> components by the following JavaScript function:

function getBirthDate() {
    var months = document.getElementById("months")
    var hidden1 =  document.getElementById("formsignup:monthField");
    hidden1.value = months.options[months.selectedIndex].text;
    var days = document.getElementById("days");
    var hidden2 = document.getElementById("formsignup:dayField");
    hidden2.value = days.options[days.selectedIndex].value;
    var years = document.getElementById("years");
    var hidden3 = document.getElementById("formsignup:yearField");
    hidden3.value = years.options[years.selectedIndex].value;
}

Here are the three <h:inputHidden> components:

<h:inputHidden value="#{signupBean.month}" id="monthField"/>
<h:inputHidden value="#{signupBean.day}" id="dayField"/>
<h:inputHidden value="#{signupBean.year}" id="yearField"/>

This is the command button that is supposed to invoke the function that copies the values to the inputs and then submits them to the backing bean.

<h:commandButton image="images/images/signup1.png" 
     styleClass="joinnow" 
     id="joinus" action="#{signupBean.save}"
     onclick="getBirthDate()" />

But they arrive as null in the backing bean. How is this caused and how can I solve it?

Edit: jQuery freezes when I try to select elements from JSF components. Is there a problem with the IDs of the elements?

Edit: below is a screenshot of the variables sent along with the HTTP request which proves that the values are properly been sent. What would be the problem with the bean?

Answer 1

您可以检查bean的范围以及在提交期间是否重新初始化它的范围吗。在那种情况下，无论值是从客户端发送的，隐藏字段都将获得其初始值。

Answer 2

You can check the object is present or not by using alert statement. Example

function getBirthDate() {
var months = document.getElementById("months")
var hidden1 =  document.getElementById("formsignup:monthField");
alert(months);alert(months.value);
alert(hidden1);alert(hidden1.value);

If the Object value is null the Id is you given to get the element is not proper.. also check the value you are getting from the object.. I think it may help