Checkbox check all with an array

adamgeorge

Hello, here's the problem I'm having.

I have a form, with some checkboxes in. I have given them the name like so, so that I can pass the values back in an array.

echo "<input type=\"checkbox\" name=\"myid[]\" value=\"$id\" class=\"check\">";

ok. that works fine. the form will return the boxes that are checked back in an array. I need to do this, because I need to be able to select multiple boxes.

What I want to do now, is make a "checkall" checkbox, that will check all the boxes when clicked.

here's what I have:

echo "<input name=\"allbox\" type=\"checkbox\" onClick=\"this.value=check(this.form.myid[])\" >";


//and the JavaScript:

<script language="JavaScript">

var checkflag = "false";
function check(field) {
	if (checkflag == "false") {
		for (i = 0; i < field.length; i++) {
			field[i].checked = true;
		}
		checkflag = "true"; 
	}
	else {
		for (i = 0; i < field.length; i++) {
			field[i].checked = false;
		}
		checkflag = "false";
	}
}
</script>

I just can't get it to work!!! It's because of the [] at the end of my checkbox name. I need this so the values are stored in an array... but it's stuffing up my JavaScript. If I remove them, it works fine. I can click, and all the boxes will be selected. However, I won't be able to return multiple values back to the server in an array.

Does anyone know a solution to this?

Thankyou
-Adam 🙂

the_Igel

don't bother with JS. if you have "checkall" checkbox, you have no need to check all other boxes.
Let your PHP script look for $checkall variable and act as if all the boxes were checked.

stuartc1

try this. (not acheck box, but works)

tomhath

It looks like you only need two minor changes. Pass your "check" function the form, not the id of the checkbox:

Then change the function to only act on elements with the right name:

...
for (i = 0; i < field.length; i++) {
if (field.name == "myid[]") {
field.checked = true;
}
}
...

adamgeorge

Thanks guys.

I ended up using a bit out of both tom and stuarts solutions.

echo "<input name=\"allbox\" type=\"checkbox\" onClick=\"check('".$identifier."[]')\">";

for loop{
echo "<input type='checkbox' name=\"".$identifier."[]\" value=\"$id\">";
}

<script language="JavaScript">
var checkflag = "false";
function check(id) { 
	temp = document.form.elements.length ;
	if (checkflag == "false") {
		for (i=0; i < temp; i++) {
			var e = document.form.elements[i];
			if ((e.name != id.value) && (e.type=='checkbox')){
				document.form.elements[i].checked=true;
			}
		} 
		checkflag = "true";
	}
	else{
		for (i=0; i < temp; i++) { 
			var e = document.form.elements[i];
			if ((e.name != id.value) && (e.type=='checkbox')){
				document.form.elements[i].checked=false;
			}
		} 
		checkflag = "false";
	}
}
</script>

One issue was, (I should have originally said but I didn't think it important at the time), the name of the checkboxes changes. The form is part of a function that can be re-used. So I needed to pass the name attribute.

So thanks guys I was able to get enough ideas to finish it off 🙂

I'm very new to JavaScript. Tell me, is there away to set a boolean value to the oposite of what it currently is? I know you can do that in Java, but I forget what the syntax is. Is it possible in JavaScript to? I can see that function could be half as long as it is if I could do that.

Thanks
- Adam 🙂

robwheelphp

Hi,

I had the same problems and use the code. I was able to get the following code working:
(basically it is rehashed code)
Thanks for your help.

<html><head>
<script language="JavaScript">
var checkflag = "false";
function check(id) {
temp = document.form.elements.length ;
if (checkflag == "false") {
for (i=0; i < temp; i++) {
var e = document.form.elements;
if ((e.name != id.value) && (e.type=='checkbox')){
document.form.elements.checked=true;
}
}
checkflag = "true";
}
else{
for (i=0; i < temp; i++) {
var e = document.form.elements;
if ((e.name != id.value) && (e.type=='checkbox')){
document.form.elements.checked=false;
}
}
checkflag = "false";
}
}
</script>
</head>
<body>

<?php
echo"<form name=\"form\">";
echo"<input name=\"allbox\" type=\"checkbox\" onClick=\"check('".$identifier."[]')\">The Check All Box <br><br>";

for ($id=0;$id<5;$id++){
echo "<input type='checkbox' name=\"".$identifier."[]\" value=\"$id\">$idror<br>";
}
echo"</form>";
?>

</body>
</html>