I'm facing a situation where ideally I'd like to have a single ActionForm
like so:
public class MyActionForm extends ActionForm {
AnotherActionForm1 af1;
AnotherActionForm2 af2;
}
When in my JSP I do:
<html:text property="af1.field1" />
I do indeed see the value as I expect. The way I did this is to have
an Action mapping that references MyActionForm, then within the Action I
instantiate AnotherActionForm1, set the value of field1 on it, and then
set af1 to that new AnotherActionForm1 instance. That all works nicely.
Here's where I run into a problem
the page I basically have 2 separate HTML forms, one for
AnotherActionForm1 and another for AnotherActionForm2. However, I have a
SINGLE submit button at the end (just plain button that makes an AJAX
request). onClick of that button, I create a query string from the values
of both forms, and make a request to the server with the query string
attached. The parameter names of the query string arguments are
af1.field1 and af2.field2, mimicing what's in MyActionForm. The mapping
that the request goes to again references MyActionForm.
What I've been told should happen is that Struts should be able to
instantiate those two nested beans and set the properties, since the
parameter names give it the information it needs. This does not however
seem to be happening.
So, two questions first, is that in fact the expected behavoir? And
two, if so, any ideas what I'm doing wrong? I can post all the pertinent
config and code, but thought it might be something more generic that
wouldn't require all that. This is the first time I've ever had a need to
nest forms like this, so it's a new question for me.
Thanks all!
Frank

So what does happen when you submit the form? Are you getting NPEs?

By the time Struts attempts to populate the form bean, the nested
forms should already be instantiated. You should have getters and
setters for af1 and af2, and getAf1() and getAf2() should not return a
null. This could be an issue if the form bean is new, either because
it's in request scope, or in session scope but was not previously
instantiated.

Hubert

9/22/06, Frank W. Zammetti <fzlists (AT) omnytex (DOT) comwrote:
I'm facing a situation where ideally I'd like to have a single ActionForm
like so:

public class MyActionForm extends ActionForm {
AnotherActionForm1 af1;
AnotherActionForm2 af2;
}

When in my JSP I do:

<html:text property="af1.field1" />

I do indeed see the value as I expect. The way I did this is to have
an Action mapping that references MyActionForm, then within the Action I
instantiate AnotherActionForm1, set the value of field1 on it, and then
set af1 to that new AnotherActionForm1 instance. That all works nicely.

Here's where I run into a problem

the page I basically have 2 separate HTML forms, one for
AnotherActionForm1 and another for AnotherActionForm2. However, I have a
SINGLE submit button at the end (just plain button that makes an AJAX
request). onClick of that button, I create a query string from the values
of both forms, and make a request to the server with the query string
attached. The parameter names of the query string arguments are
af1.field1 and af2.field2, mimicing what's in MyActionForm. The mapping
that the request goes to again references MyActionForm.

What I've been told should happen is that Struts should be able to
instantiate those two nested beans and set the properties, since the
parameter names give it the information it needs. This does not however
seem to be happening.

So, two questions first, is that in fact the expected behavoir? And
two, if so, any ideas what I'm doing wrong? I can post all the pertinent
config and code, but thought it might be something more generic that
wouldn't require all that. This is the first time I've ever had a need to
nest forms like this, so it's a new question for me.

Thanks all!

Frank
--

Hi Hubert,

Yes, I get nulls for af1 and af2 I do have getters and setters for them.

Lemme throw some data your way I was hoping to avoid posting all this,
but I suspect there to be something my eyes just aren't catching, so

Here's ActionForm1:

package app.test.formbeans;
import ;
public class Action1Form extends ActionForm {
private String field1;
public void setField1(String inField1) {
this.field1 = inField1;
}
public String getField1() {
return this.field1;
}
}

ActionForm2 is identical, just replacing the number 1 with 2 everywhere.
Here's MasterForm:

package app.test.formbeans;
import ;
public class MasterForm extends ActionForm {
public Action1Form action1Form;
public Action2Form action2Form;
public void setAction1Form(Action1Form inAction1Form) {
this.action1Form = inAction1Form;
}
public Action1Form getAction1Form() {
return this.action1Form;
}
public void setAction2Form(Action2Form inAction2Form) {
this.action2Form = inAction2Form;
}
public Action2Form getAction2Form() {
return this.action2Form;
}
}

The Action everything gets submitted to is just a ForwardAction, which
forwards to:

<%@ page language="java" import="app.test.formbeans.*" %>
<%
MasterForm masterForm = (MasterForm)request.getAttribute("masterForm");
%>
<%="masterForm = " + masterForm + "<br>"%>
<%
Tab1Form tab1Form = null;
Tab2Form tab2Form = null;
if (masterForm != null) {
tab1Form = masterForm.getTab1Form();
tab2Form = masterForm.getTab2Form();
}
%>
<%="tab1Form = " + tab1Form + "<br>"%>
<%="tab2Form = " + tab2Form + "<br>"%>
<% if (tab1Form != null) { %>
<%="field1 = " + tab1Form.getField1() + "<br>"%>
<% } %>
<% if (tab2Form != null) { %>
<%="field2 = " + tab2Form.getField2() + "<br>"%>
<% } %>

The result I see from this is:

masterForm = app.test.formbeans.MasterForm@e3849c
tab1Form = null
tab2Form = null

The page that does that submit, in its final rendered form on the client is:

<html>
<head>
<script>
var finalSubmit = null;
function getXHR() {
if (window.XMLHttpRequest) {
return new XMLHttpRequest();
} else if (window.ActiveX) {
return new ActiveX("Microsoft.XMLHTTP");
}
}
function submitAll() {
var tab1Form = dojo.io.encodeForm(
document.getElementById("tab1Form"));
var tab2Form = dojo.io.encodeForm(
document.getElementById("tab2Form"));
finalSubmit = getXHR();
finalSubmit.onreadystatechange = finalSubmitCallback;
finalSubmit.open("PST", "final.do", true);
finalSubmit.send(tab1Form + tab2Form);
}
function finalSubmitCallback() {
if (finalSubmit.readyState == 4) {
document.getElementById("divResult").innerHTML =
finalSubmit.responseText;
}
}
</script>
</head>
<body onload="init();">
<form name="masterForm" id="tab1Form" method="post" action="/test/tab1.do">
Field1: <input name="tab1Form.field1" value="val1" type="text"><br>
</form>
<br>
<form name="masterForm" id="tab2Form" method="post" action="/test/tab2.do">
Field2: <input name="tab2Form.field2" value="val2" type="text"><br>
</form>
<br>
<input value="Submit All" onclick="submitAll();" type="button">
<br><br>
<div id="divResult"></div>
</body>
</html>

Note that I removed all the Dojo-related stuff, and some stuff that isn't
related to this submissino, just to try and keep it small, but, the
important thing to note is that when the submission is made, the request
that goes across is a PST to , as
expected, and the PST body is:

also as expected, verified in Firebug. Lastly, here's struts-config:

<?xml version="1.0" encoding="IS" ?>
<!DCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts
Configuration 1.2//EN"
"">
<struts-config>
<form-beans>
<form-bean name="masterForm" type="app.test.formbeans.MasterForm" />
</form-beans>
<action-mappings>
<action path="/final" type="app.test.actions.FinalAction"
name="masterForm" scope="request" validate="false">
<forward name="defaultForward" path="/final.jsp" />
</action>
</action-mappings>
</struts-config>

Note here that I removed the stuff that generated the markup from above
too, since that seems to be working just fine, I'm pretty sure this is all
that would be relevant.

So, seeing any obvious blunders on my part? Thanks Hubert!

Frank

Sorry, by af1 and af2 I did mean actionForm1 and actionForm2 my mistake
wasn't quite *THAT* obvious! ;) LL
Frank

In your no-arg constructor of your outer ActionForm (the container), make
sure it instantiates each of the nested ActionForms using their no-arg
constructors.
(*Chris*)

9/22/06, Frank W. Zammetti <fzlists (AT) omnytex (DOT) comwrote:

Sorry, by af1 and af2 I did mean actionForm1 and actionForm2 my mistake
wasn't quite *THAT* obvious! ;) LL

Frank
--

Either that or create new beans (if they're null) when their getters are called.

By the time Struts attempts to populate the form bean, the nested
forms should already be instantiated. MasterForm.getAction1Form() and
MasterForm.getAction2Form() should not return a null.

Hubert

9/22/06, Chris Pratt <thechrispratt (AT) gmail (DOT) comwrote:
In your no-arg constructor of your outer ActionForm (the container), make
sure it instantiates each of the nested ActionForms using their no-arg
constructors.
(*Chris*)

9/22/06, Frank W. Zammetti <fzlists (AT) omnytex (DOT) comwrote:

Sorry, by af1 and af2 I did mean actionForm1 and actionForm2 my mistake
wasn't quite *THAT* obvious! ;) LL

Frank
--

Hi Chris thanks for the suggestion, I gave that a shot at one point
actually what I get is now the fields in the subforms (I guess that's
as good a term as any!) don't get set

masterForm = app.test.formbeans.MasterForm@141fab6
tab1Form = app.test.formbeans.Tab1Form@b301f2
tab2Form = app.test.formbeans.Tab2Form@44cbbe
field1 = null
field2 = null

That's what I see in my final JSP output.

Frank

As a follow-up, I threw some logging in the field1 and field2 setters in
the subbeans they don't appear to ever get called. I don't have to do
anything special to tell Struts I'm using nested beans, do I? I didn't
think so
Frank

It still sounds like Struts is getting nulls for the subbeans when it
tries to populate subbean.fieldX. Put some more logging, this time in
the getters for the subbean in MasterForm, and log what it's
returning.

Hubert

9/22/06, Frank W. Zammetti <fzlists (AT) omnytex (DOT) comwrote:
As a follow-up, I threw some logging in the field1 and field2 setters in
the subbeans they don't appear to ever get called. I don't have to do
anything special to tell Struts I'm using nested beans, do I? I didn't
think so

Frank
--

Yeah, I'm sure that previous post was confusing :) tab1Form and tab2Form
are the names of the action forms I forgot I changed them at one point.
The code itself all references the proper names.

Hehe, way ahead of you :) I put logging in every method constructors,
getters setter, all three forms. Here's the output:

MasterForm constructor
Tab1Form constructor
Tab2Form constructor
IN JSP--
MasterForm getTab1Form() = app.test.formbeans.Tab1Form@8ab08f
MasterForm getTab2Form() = app.test.formbeans.Tab2Form@14d921a
getting field1 = null
getting field2 = null

Notice the fields don't get set, nor do the subbeans get set on the
containing bean. The MasterForm constructor instantiates Tab1Form and
Tab2Form, as the output indicates.

Frank

I can't see anything that would cause your problem.
I guess if it were me, I'd fire up my debugger and start stepping
through some code.
Sorry.
All I can say at this point is that I know what you're doing is
possible cause that's how FormDef does nested beans.

Hubert

9/22/06, Frank W. Zammetti <fzlists (AT) omnytex (DOT) comwrote:
Hehe, way ahead of you :) I put logging in every method constructors,
getters setter, all three forms. Here's the output:

MasterForm constructor
Tab1Form constructor
Tab2Form constructor
IN JSP--
MasterForm getTab1Form() = app.test.formbeans.Tab1Form@8ab08f
MasterForm getTab2Form() = app.test.formbeans.Tab2Form@14d921a
getting field1 = null
getting field2 = null

Notice the fields don't get set, nor do the subbeans get set on the
containing bean. The MasterForm constructor instantiates Tab1Form and
Tab2Form, as the output indicates.

Frank
--

Quick update: it has something to do with the fact that its an AJAX
request at the end or because its a PST, one or the other I built a
URL with the parameters as a query string, and it worked fine I don't
know what it is yet yet, exploring now the request looks identical
aside from method, which shouldn't matter, AFAIKT, but something is
obviously bad with it will let you know when I figure it out

Frank

Got it had to explicitly set the Content-Type of the request to
on the XMLHttpRequest object. Didn't
even occur to me because I set the method to PST, didn't even consider
that might not be sufficient. Weird thing is, I know I have code where I
PST but don't set the header and it works, not sure why these nested
names would be different.

Well, should it come up for anyone else, there you go :)

Frank