Problems with <SELECT> and hidden elements!!

[Omar]

Hi,

In a JSP I have the next:

....
codigo = "<select name='" + nombre + "'>\n<option selected
value='default'>Escoge</option><option value='todos'>Todos</option>";
if (miRS != null)
while (miRS.next())
{
valorColumna = miRS.getString(nombre);
if (valorColumna.trim().equals(""))
do
{
miRS.next();
valorColumna = miRS.getString(nombre);
} while (valorColumna.trim().equals(""));
if (!valorColumna.trim().equals(""))
codigo = codigo + "<option value='" + valorColumna + "'>" +
valorColumna + "</option>";
} // fin del while
codigo = codigo + "</select><input type='hidden' name='valor" +
posicion + "' value='+this.options[this.selectedIndex].value+'>";
....

There, the hidden element should get the value of the selection made
by the user in the drop down menu.

In other JSP, I have to get this value. However, the value returned
is: +this.options[this.selectedIndex].value+

How can I get the selected item value?????

TIA

[Fred Oz]

Omar wrote:

Hi,

In a JSP I have the next:

...
codigo = "<select name='" + nombre + "'>\n<option selected
value='default'>Escoge</option><option value='todos'>Todos</option>";
if (miRS != null)
while (miRS.next())
{
valorColumna = miRS.getString(nombre);
if (valorColumna.trim().equals(""))
do
{
miRS.next();
valorColumna = miRS.getString(nombre);
} while (valorColumna.trim().equals(""));
if (!valorColumna.trim().equals(""))
codigo = codigo + "<option value='" + valorColumna + "'>" +
valorColumna + "</option>";
} // fin del while
codigo = codigo + "</select><input type='hidden' name='valor" +
posicion + "' value='+this.options[this.selectedIndex].value+'>";
...

There, the hidden element should get the value of the selection made
by the user in the drop down menu.

In other JSP, I have to get this value. However, the value returned
is: +this.options[this.selectedIndex].value+

Script in a form element's value attribute won't be executed, you
should only put text in there.

If you want to put the value of the selected option into the hidden
element, the best method is to use the form's onsubmit intrinsic
event. Rather than try to munge your script, here's a simple
example:

<form action="" onsubmit="
this.valorPos.value = this.nombre.value;
">
<select name="nombre">
<option value="default" selected>Select an option</option>
<option value="valorColumna0">Option 0</option>
<option value="valorColumna1">Option 1</option>
</select><br>
<input type="hidden" name="valorPos" value="default">
<input type="button" value="Show valorPos value" onclick="
alert(this.form.valorPos.value);
">
<input type="reset" onclick="
this.form.valorPos.value='default';
">
</form>

Note that while the reset button returns the hidden element's value
to 'default' in IE, it doesn't in Firefox, hence the 'onclick' code.
This may or may not be an issue for you.

You need to decide when the value needs to be put into the the hidden
input. Using an onchange has lots of issues with making sure the
value in the hidden input is aligned with what is shown in the
select.

In addition to the reset issue above, in Firefox and IE, re-loading
the page will return the value of the hidden input to 'default', but
the selected item of 'nombre' will not change.

As a note, it seems popular to get the value of a select thusly:

this.valorPos.value = this.nombre[this.nombre.selectedIndex].value;

but I think the first mentioned method should suffice. Any comments?

--
Fred

[Omar Rodríguez]

Thank you, Fred.

As you realized, I'm newbie in this.

I have a question. Is it possible to get the value of the selected item
using JS and passing it to a JSP file??

My variable codigo (code) is used to store all the code of the HTML
page. This variable is in a Java class, which is used in a JSP file.
(Let's say JSP1)

In JSP1 there're more than 100 dropdown menus. (I mean, the code I
posted is inside a loop that repeats itself more than 100 times.) But
only one of them can be selected at the same time. However, I have to
pass all the values to the other JSP to be able to get the selected one
and to do other stuff with it.

I appreciate your help.

*** Sent via Developersdex http://www.developersdex.com ***

[FredOz]

Omar Rodríguez wrote:

Thank you, Fred.

As you realized, I'm newbie in this.

I have a question. Is it possible to get the value of the selected item
using JS and passing it to a JSP file??
Sorry, JSP ain't my bag, baby. Someone here may volunteer, but you'd
be better off going to a JSP news group:

<URL:http://groups-beta.google.com/group/comp.lang.java.programmer>

My variable codigo (code) is used to store all the code of the HTML
page. This variable is in a Java class, which is used in a JSP file.
(Let's say JSP1)

In JSP1 there're more than 100 dropdown menus. (I mean, the code I
posted is inside a loop that repeats itself more than 100 times.) But
only one of them can be selected at the same time. However, I have to
pass all the values to the other JSP to be able to get the selected one
and to do other stuff with it.

I appreciate your help.

*** Sent via Developersdex http://www.developersdex.com ***

--
Fred

[Omar]

Hi,

Is it possible to set to a hidden element the value of an item
selected in a dropdown menu using a JavaScript funtion or something??

I appreciate your help.

[Fred Oz]

Omar wrote:

Hi,

Is it possible to set to a hidden element the value of an item
selected in a dropdown menu using a JavaScript funtion or something??

I appreciate your help.

Yes, that was in my first post. Somehow the submit button went
missing, below is a version with a submit button.

The reason I suggested doing it on submit is because that is the only
time you can guarantee that you can make the two the same. The only
other event that makes any sense is using onchange, but I don't
recommend that for the reasons given.

Actually, some of the behaviours don't happen in version 1.03 of
Firefox - I just updated and the reset thing now works as per IE and
navigation keeps the selection and value. Re-loading the page does
not change either value. But I think the behaviour across all
browsers still warrants some extra precautions.

If you want to try it, move/copy the onsubmit code to an onchange on
the select...

<select name="nombre" onchange="
this.form.valorPos.value = this.value;
">

You could create a listener that is started by onchange and looks at
the value of the select every 50 milliseconds or so and makes the
values the same, but I can't see the point in doing it when onsubmit
will do a better job, without hogging CPU and without the 1-in-1000
chance (or maybe it's higher, I dunno) that the user changes their
selection and submits the form before the listener updates the value.

So you'd add an onsubmit anyway...
<form action="" onsubmit="
this.valorPos.value = this.nombre.value;
">
<select name="nombre">
<option value="default" selected>Select an option</option>
<option value="valorColumna0">Option 0</option>
<option value="valorColumna1">Option 1</option>
</select><br>
<input type="hidden" name="valorPos" value="default">
<input type="button" value="Show valorPos value" onclick="
alert(this.form.valorPos.value);
">
<input type="reset" onclick="
this.form.valorPos.value='default';
">
<input type="submit" value="Send data...">
</form>

--
Fred

[Omar]

Fred, thank you for your time.
I'll work on your idea.

- Omar.