pre-checking a checkbox from array values when validating a form

[cparekh]

Hi,

 

I'm setting server-side validation for a form and would like to pre-check any checkboxes that have been checked by the user when I call the form again.

 

I'm using in_array to check if a value is present and this works when I call it like this:

//ERROR CHECKING for array
	echo count($location);
	if (in_array("Africa", $location)) 
		{
    			echo "Africa - yes<br/>";
		}
	if (in_array("Europe", $location)) 
		{
    			echo "Europe - yes<br/>";
		}

 

...however I get this error

Warning: in_array() [function.in-array]: Wrong datatype for second argument in C:\xampp\htdocs\profile\index.php on line 294

> Africa

when I call in_array like this in a conditional:

<input type='checkbox' name='geographic[]' value='Africa' <?php if(in_array("Africa", $location)) {echo "checked='checked'";} ?> >

 

Having searched for solutions to this error, it usually has to do with a missing ';' however everything looks ok as far as I can tell.

 

If someone has an idea why it's throwing up that error or knows of another way to pre-populate checkboxes from an array I'd greatly appreciate the help.

[Cep]

What is $location?

[cparekh]

Hi Cep,

 

I set $location = $_POST['geographic']; to hold the array when the user submits.

[kenrbnsn]

This error has nothing to do with a missing semi-colon, it is telling you that your second argument to the in_array() function is not an array. Do a

<?php
echo '<pre>' . print_r($location,true) . '</pre>';
?>

to see what's in that variable.

 

 

Ken

[cparekh]

Hi Ken,

 

this is the error checking I've done, now including what you've suggested:

 

//ERROR CHECKING for array
	echo count($location);

                if (in_array("Africa", $location)) 
		{
    			echo "Africa - yes<br/>";
		}
	if (in_array("Europe", $location)) 
		{
    			echo "Europe - yes<br/>";
		}

	echo '<pre>' . print_r($location,true) . '</pre><br/>';

 

(note the in_array check for 'Africa' & 'Europe') and the result is...

2Africa - yes
Europe - yes

Array
(
    [0] => Africa
    [1] => Europe
)

[Cep]

If you do var_dump($location); Do you get an array?

[kenrbnsn]

Change

<input type='checkbox' name='geographic[]' value='Africa' <?php if(in_array("Africa", $location)) {echo "checked='checked'";} ?> >

to

<input type='checkbox' name='geographic[]' value='Africa' <?php if(is_array($location) && in_array("Africa", $location)) {echo "checked='checked'";} ?> >

 

This will check if $location is an array first.

 

Ken

[cparekh]

Cep,

 

var_dump($location); output the following (including other error checking as above)

2Africa - yes
Europe - yes

Array
(
    [0] => Africa
    [1] => Europe
)


array(2) { [0]=> string(6) "Africa" [1]=> string(6) "Europe" }

 

 

[cparekh]

Ken,

 

tried that and it works!

 

I'm not sure I get it though - if it is an array, why would in-array throw a wobbly?

 

Thanks for that - phew!

[kenrbnsn]

You're code produced the error when it was not an array. Adding the check makes sure it's an array before checking whether the value is in the array.

 

Since you didn't post the rest of your code, I'm assuming that you go the error the first time through the code, before the form had been filled in and submitted.

 

Ken

[cparekh]

Ah yes, of course! No array built before submission.

 

Thanks again Ken.