Select One Menu returning Null value in the Backing bean?

Question

I need to return the selected value to the bean for further processing but its returning null value .

<h:form>

 <h:panelGrid columns="1">
                    <p:outputLabel id="state" value="State Name"></p:outputLabel>
                    <p:selectOneMenu id="statemenu" style="width:300px;"
                        value="#{MenuBean.state}">
                        <f:selectItem itemLabel="Select One"></f:selectItem>
                        <f:selectItems value="#{MenuBean.stateList}"></f:selectItems>

                        <p:ajax listener="#{MenuBean.stateChange}" update="dist"
                            process="@this" immediate="true"></p:ajax>

                    </p:selectOneMenu>

                    <br></br>
                    <p:outputLabel value="District"></p:outputLabel>
                    <p:selectOneMenu id="dist" style="width:300px;"
                        value="#{MenuBean.district}">
                        <f:selectItem itemLabel="Select One"></f:selectItem>
                        <f:selectItems value="#{MenuBean.districtList}"></f:selectItems>
                    </p:selectOneMenu>
                </h:panelGrid>

<h:panelGrid style="position:relative; left:165px" columns="2"
                cellpadding="2" cellspacing="2">
                <p:commandButton value="Reset"
                    style='font-family: font-family : Baskerville, "Baskerville Old Face",
    "Hoefler Text", Garamond, "Times New Roman", serif;;
font-size: 13px; font-weight: normal'></p:commandButton>
                <p:commandButton value="Submit" immediate="true"
                    action="#{MenuBean.getValues}"
                    style='font-family: font-family : Baskerville, "Baskerville Old Face",
    "Hoefler Text", Garamond, "Times New Roman", serif;;
font-size: 14px; font-weight: normal'></p:commandButton>
            </h:panelGrid>
</h:form>

and the backing beaning is

private String state;

  private String district;
        private Map<String,String> StateList = new HashMap<String,String> ();;
        private Map<String,String>  DistrictList = new HashMap<String,String>();




public MenuBean() {
        System.out.println("Entering the Constructor");
        StateList = DBConnector.StateList();
        // DistrictList = DBConnector.DistrictList();
    }



 public void stateChange() {
            DistrictList = DBConnector.DistrictList();
    }
public void getValues() {
        System.out.println("getting the values");
        System.out.println(getState());
        System.out.println(getDistrict());
    }

I have edited the code snippet i guess it will give you a insight on it .

First change `f:ajax` by `p:ajax`, second `MenuBean.stateList` is a list of **Entity** or **String**, if are first you need a **converter**. Please write code method `stateChange` — Mathew Rock, Mar 13 '14 at 08:54
@MathewRock with p:ajax its not working second the stateList is an arraylist of strings .. — Rajeev Massey, Mar 13 '14 at 09:05
It is difficult to understand what you really have on the page. Can you add more xhtml code here, so that we would see the form. The only thing that I can say for sure that when listener #{MenuBean.stateChange} is called on change of select menu it will not have new value that is assigned to the #{MenuBean.state} because you have immediate="true" attribute there. Immediate skips any model updates. It just calls the method. — trims, Mar 13 '14 at 09:11
The bean is not so interesting as the page xhtml. I want to see the everything that is inside the — trims, Mar 13 '14 at 09:44
@trims i have update the post with all the required information — Rajeev Massey, Mar 13 '14 at 09:52

Mathew Rock · Accepted Answer · 2014-03-14T06:40:27.260

1

Change your method stateChange to :

public void stateChange(AjaxBehaviorEvent event) { 
    setState(event.getComponent().getAttributes().get("value"));
    DistrictList = DBConnector.DistrictList();
}

And change <f:selectItems value="#{MenuBean.stateList}"></f:selectItems> to <f:selectItems value="#{MenuBean.stateList}" var="state" itemValue="state.id" itemLabel="state.id"/>

edited Mar 14 '14 at 06:40

answered Mar 13 '14 at 09:58

Mathew Rock

989
2
14
32

Did you try change `f:selectItems` @user3383174 – Mathew Rock Mar 13 '14 at 13:43
what gives you in `event.getComponent().getAttributes().get("value")`? – Mathew Rock Mar 14 '14 at 06:40

score 0 · Answer 2 · edited May 23 '17 at 12:21

0

So after you posted full xhtml I see the reason why it is not working.

you have on the page <p:commandButton value="Submit" immediate="true". You have immediate attribute which means no values from inputs or dropdowns will be set to you beans. Immediate attribute forces jsf to skip all phases except invoke application and render response. To read more about jsf phases read this post

You need to remove this attribute from submit button and it should start working. Also according to this post in primefaces update="@form". So your button will look like this:

<p:commandButton value="Submit" update="@form" action="#{MenuBean.getValues}"

edited May 23 '17 at 12:21

Community

1
1

answered Mar 13 '14 at 10:02

trims

453
4
9

still its not working .. So is there any other way .?? – Rajeev Massey Mar 13 '14 at 10:35
try to add process="@form" – trims Mar 13 '14 at 10:46
getting the values null null Still this answer – Rajeev Massey Mar 13 '14 at 10:49
this is very wierd. Maybe try to use the h:commandButton. If it doesn't help I would recommend you to look what ajax request is submitted when you click submit button. Use network panel in chrome developers console. – trims Mar 13 '14 at 12:26
after removing the ajax . the whole page is refresher and all the validations are applie giving required messages .. – Rajeev Massey Mar 14 '14 at 05:28
after removing the ajax the value of state is being submitted ..but i need to update the district menu from the db through ajax ,, so how to go about ... – Rajeev Massey Mar 14 '14 at 05:50

Select One Menu returning Null value in the Backing bean?

2 Answers2