Limit what can be entered on text field.

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January 30th, 2013, 08:52 AM

MikkM

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Limit what can be entered on text field.

Hello, i have a input form on my site.

Code:

<form method="post" action="Untitled-2.php">
<input name="search" style="font-size:110px" type="text" class="searchBox" size="700"   maxlength="6">
</form>

I managed to limit total length to 6 chars, but now i want to go deeper.

I want to let users to enter chars only in this format
"111AAA" that means 3 letters and 3 numbers and only this way , not AAA111 or 1A1A1A, only 111AAA

How can i achive this? Maybe javascript?

Best Regards
Mix

January 30th, 2013, 10:03 AM

Jacques1

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Hi,

if you actually want to enforce those restrictions, you need to validate the input on your server. HTML attributes or JavaScript can only be used to inform the user about errors and make the form more convenient.

January 30th, 2013, 02:04 PM

MikkM

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Quote:

Originally Posted by Jacques1

What method is best to achive this? Maybe somehow check with php before form submiting?

I´m submiting my form like this:

PHP Code:


		
			
if (isset($_POST)) {

  if (isset($_POST["search"])){

    $a = $_POST['search'];

    echo $a;

    //do something more

January 30th, 2013, 02:13 PM

notflip

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You can also use jquery or javascript with a regular expression ( preg_match ) to check client side. Regular expressions are used to check for patterns and can check forvthe most complex patterns.

January 30th, 2013, 05:26 PM

Catacaustic

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Checking string length with PHP is simple.

PHP Code:


		
			
 $length = strlen ($_POST['search']);

Then you can check that the length is between whatever you need it to be.

January 30th, 2013, 06:07 PM

Jacques1

pollyanna

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Well, since you want a certain pattern, you can check that with a regular expression (like notflip already said):

The regular expression for a string of "three letters (a to z, A to Z) followed by three decimal digits" is

Code:

/^[a-z]{3}\d{3}$/i

So the PHP check would be

PHP Code:


		
			
if ( preg_match('/^[a-z]{3}\\d{3}$/i', $_POST['search']) )

    // input matches

else

    // input doesn't match

Note that you don't need an explicit length check in this case, because it's implied by the pattern.

May 7th, 2013, 04:07 AM

shellygill

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you will need to use validations in your command as mentioned above by Jacques1.

May 7th, 2013, 10:16 AM

coding1

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Server side validation is the way to go. Use Jaques1 example.

Limit what can be entered on text field.

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