JSF selectOneMenu + Database Values

[Josh Juneau]

I am trying to create a <selectOneMenu> tag using database values for the <selectItem> tag "itemValue" and "itemLabel" attributes.

I am using a backing bean to populate the database values, however I cannot get this to work properly. My attempts fail when I try to use an iterating scriptlet and backing bean values such as:

<h:selectOneMenu id="thisid" value="#{backingbean.thisproperty}" >
<% String[] valuearray = bean.getvaluearray;
for (int i=0; i<=valuearray.length-1; i++){ %>
<f:selectItem itemValue="#{backingbean.databaseSequenceValue}"
itemLabel="#{backingbean.dynamiclabel" />
<% } %>
</h:selectOneMenu>

Is there a way to achieve database backing values for JSF itemValue and/or itemLabel attributes or do I need to create a custom JSF component for this process?

Any help would be greatly appreciated as this issue is causing me to turn away from JSF...I use dynamic database values to populate most of my web applications, and drop-down lists are used extensively.

Thanks in advance

[will lopez]

Hello:

Not sure this will help you out but I found this code that uses 1.0 tags:
<f:use_faces>
<h:form formName="myForm">
<h:selectone_menu size="3"
valueRef="selectedCountryBean.selectedCountry">
<h:selectitems valueRef="countryListBean.countryList"/>
</h:selectone_menu>
<h:command_button commandName="submit" label="submit"/>
<hr>
You selected:
<h utput_text valueRef="selectedCountryBean.selectedCountry"/>
</h:form>
</f:use_faces>

...converting it to 1.1 looks like this:
<f:view>
<h:form id="myForm">
<h:selectOneMenu value="#{selectedCountryBean.selectedCountry}">
<f:selectItems value="#{countryListBean.countryList}"/>
</h:selectOneMenu>
<h:commandButton value="submit" />
<hr>
You selected: <h utputText value="#selectedCountryBean.selectedCountry}"/>
</h:form>
</f:view>

...I'm no guru but from what I gathered I thought the implementation knew that it had a collection so one didn't have to use an iterating tag or loop but I keep getting a NPE with this code...I haven't had time to figure it out yet.

[Josh Juneau]

Thanks, I will give it a try and post my results...

[Josh Juneau]

That works!

I had to define a method in the backing bean which returned a Collection (ArrayList of SelectItems) of the items I wanted to appear in the SelectMenu...

Thanks for the help!

[Clement S.]

Can you show how you get that to work?

[Josh Juneau]

First, you set up your page (JSP in this case) as follows:

<f:view>
<h:form id="mytestform" >
<h:selectOneMenu value="#{BackingBean.mySubject" >
<f:selectItems value="#{BackingBean.mySubjectList}" />
</h:selectOneMenu>
<h:commandButton value="submit" />
</h:form>
</f:view>

Next, you must use a backing bean method to populate an ArrayList then then pass it back to the page as a "Collection":

...

public void setMySubject(String value)
{
mySubject = value;
}
public String getMySubject()
{
return mySubject;
}

...
public String mySubject = null;
private static ArrayList mySubjectList = null;

...

public Collection myBackingBeanArray(){

try{
myQuery = "select subject from MYTABLE " +
"order by MY_id";

rset = db.executeQuery(myQuery);
while(rset.next()){
mySubjectList.add(new SelectItem(rset.getString("subject")));

}
...

}

The first time I tried to implement this solution, I failed to use the new SelectItem() method. Remember to import javax.faces.model.SelectItem to make this work!

Good luck!

[jrthor2]

Could this be done using a properties (text) file? If so, could someone show me how to do the bean?

Thanks