beginner: form validation checkbox problem

[nescio]

hello,

i am making a form using php/html/javascript
a part of the form is (email address) comming from a database.
the amount of addresses is always different.
every address has a checkbox.
people have the check at least one checkbox.

i have made a form check to see of at least one checkbox is selected.
this workts fine.

but the problem is:
when there is only one address the form validation does not work!

i cannot get it to work.

thanks,
---------------------------- source code form ---------------------
<form onsubmit='return FormZoekMail(this)' name='mail' action='<? echo
$_SERVER['PHP_SELF']; ?>' method='post'>
<input type='checkbox' name='mailadres[]' value='some value'>
---------------------------------------------------------------

----------------------- source code javascript
function ----------------------

function FormZoekMail(hetForm){
leeg = 0
aantalElementen = 0

aantalElementen = hetForm['mailadres[]'].length;

kort = hetForm['mailadres[]'];

for(x = 0; x < aantalElementen; x++){
if(kort[x].checked != true){
leeg++;
}
}


if(leeg == aantalElementen){
alert('u moet minstens een mailadres selecteren');
return(false);
}
-----------------------------------------------------------------

[Erwin Moller]

nescio wrote:

hello,

i am making a form using php/html/javascript
a part of the form is (email address) comming from a database.
the amount of addresses is always different.
every address has a checkbox.
people have the check at least one checkbox.

i have made a form check to see of at least one checkbox is selected.
this workts fine.

but the problem is:
when there is only one address the form validation does not work!

i cannot get it to work.

Hi,

That is a mean one. :P
I remember pulling my hairs out over that.

It works like this:
Javascript will only make an array of your radiobuttons if it encouters more
than 1 element.
By design.
Just to make the life of developers misserable.
Fun, isn't it?
;-)

Solution: Just check if it is an array, if not, treat it like a simple
value.

Regards,
Erwin Moller

>
thanks,
---------------------------- source code form ---------------------
<form onsubmit='return FormZoekMail(this)' name='mail' action='<? echo
$_SERVER['PHP_SELF']; ?>' method='post'>
<input type='checkbox' name='mailadres[]' value='some value'>
---------------------------------------------------------------

----------------------- source code javascript
function ----------------------

function FormZoekMail(hetForm){
leeg = 0
aantalElementen = 0

aantalElementen = hetForm['mailadres[]'].length;

kort = hetForm['mailadres[]'];

for(x = 0; x < aantalElementen; x++){
if(kort[x].checked != true){
leeg++;
}
}


if(leeg == aantalElementen){
alert('u moet minstens een mailadres selecteren');
return(false);
}
-----------------------------------------------------------------

[Richard Cornford]

nescio wrote:
<snip>

but the problem is:
when there is only one address the form validation does
not work!

i cannot get it to work.

<snip>

<URL: http://jibbering.com/faq/faq_notes/f...ess.html#faBut >

Richard.

[nescio]

Solution: Just check if it is an array, if not, treat it like a simple
value.

thanks for your advice.

first of all, my knowledge of javascript is rather limited, but i am eager
to learn.

it tried the function typeof() to find out if there is one or more then one
element(s).
but in both cases it returns 'object';

in the form there are brackets around the name field:
<input type = checkbox name='emailadres[]' value = 'something'>

these brackets can't be omitted because php needs them.

so, my next question is: how do i find, using javascript, if the value is an
array or a string or whatever.
thanks

[Richard Cornford]

nescio wrote:

>Solution: Just check if it is an array, if not, treat it like a simple
value.

thanks for your advice.

first of all, my knowledge of javascript is rather limited, but i am eager
to learn.

it tried the function typeof()

It is not a function; - typeof - is an operator. I discourage the habit
of putting parenthesise around its operand because that does act to
confuse people into thinking that it is a function and that its operand
is an argument to a function call. What is happening with - typeof(x) -
is that the tokenizer sees that the first - ( - cannot be a character
in an identifier so it can see that - typeof - is a single token, which
it then sees as a keyword token declaring the - typeof - operator. It
is a unary operator which expects a right hand side operand that is an
expression, so the interpreter tries to find an expression if the
following tokens, and finds one in the form of - (x) -, which is the
grouping operators (the parentheses) surrounding their operand (the
Identifier - x - in this case).

The result may resemble a function call but - typeof(x) - is
functionally equivalent to - typeof x - (and one character longer).

to find out if there is one or more then one
element(s).
but in both cases it returns 'object';

The possibilities are a single <INPUT type="checkbox"element or a
collection of such elements, both are objects so will be reported as
objects.

in the form there are brackets around the name field:
<input type = checkbox name='emailadres[]' value = 'something'>

these brackets can't be omitted because php needs them.

That is not strictly true, but not important as you can use bracket
notation in javascript to avoid the square brackets in the name being
an issue:-

<URL: http://www.jibbering.com/faq/faq_not..._brackets.html >

so, my next question is: how do i find, using javascript, if the value
is an array or a string or whatever.

It will never be a string, and a collection is only array-like, it is
not actually and Array (in the javascript sense). See:-

<URL: http://www.jibbering.com/faq/faq_not...ess.html#faBut >

Richard.

[nescio]

it is all working now, thank you all for your help