PHP validation form data

Question

I need to validate submitted form data:

To check whether fields are empty.
Proceed to validate non-empty data.

x – allows only spaces, underscore, aplha numeric characters. y – checks whether it is an image or not.

I'm using below code, it does not work. It is not validating and printing error.

<?php
$validate = array(
    '/^[a-z\d ]{4,20}$/i' => array('$x' => 'Please enter valid name.'),
    '/^[a-z\d ]{4,20}$/i' => array('$y' => 'Please enter a real category.')
);

$error = '';

foreach ($validate as $key => $field)
{
    if (preg_match($key,$field[0]))
    {
       $error.= $field[0];
    }
}

if ($error)
{
    echo $error;
    exit;
}

Where does the variable $validate come from? I guess it should be $regEx? — Geert
– Geert, Commented Jun 19, 2012 at 8:36
Define it does not work. Does the validation pass when it should fail, does it fail when it should pass? — MrCode
– MrCode, Commented Jun 19, 2012 at 8:38

Roman · Accepted Answer · 2012-06-19 09:16:20Z

1

You're matching your regex against your error message, not your submitted strings ($x and $y).

You probably ment to do something like this:

$validate = array(
    '/^[a-z\d ]{4,20}$/i' => array($x, "Please enter valid name."),  //change here
    '/^[a-z\d ]{4,20}$/i' => array($y, "Please enter a real category.") //change here
);

$error = '';
foreach ($validate as $key => $field)
{
    if (preg_match($key,$field[0]))
    {
       $error.= $field[1]; //change here
    }
}

if($error)
{
    echo $error;
    exit;
}

UPDATE

how I would do it.

$validate = array(
    array($x, '/^[a-z\d ]{4,20}$/i', "Please enter valid name."),
    array($y, '/^[a-z\d ]{4,20}$/i', "Please enter a real category."),
    array($phone, '/^\(?[0-9]{3}\)?|[0-9]{3}[-. ]? [0-9]{3}[-. ]?[0-9]{4}$/' , "Please enter a valid phone number")
);

$error = '';
foreach ($validate as $validation)
{
    if (!preg_match($validation[1],$validation[0]))
    {
       $error .= $validation[2]; 
    }
}

if($error != '')
{
    echo $error;
    exit;
}

$validate now is an array of your fields, each expressed with it's own array containing error message, regex to match it against and submitted subject.

edited Jun 19, 2012 at 9:16

answered Jun 19, 2012 at 8:44

Roman

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8 Comments

user1415759 Over a year ago

:Did you try it out in local host,if the user enter less than 4 or special characters,it should print the error message.Both x and y are two different field data so each have diff regex.Your code does not give me any error,if i enter characters less than 4.

user1415759 Over a year ago

:There can be nfeilds and n regex.I can n't write field[0],field[1].

Roman Over a year ago

I corrected only the obvious part about matching the regex against the error message. I didn't touch your validation logic. Indeed, You're printing the error message only when the string matches, which, I presume, means that it is valid. I'll append to my answer how I would do it.

user1415759 Over a year ago

:Will it validate empty feilds.Say,if'i've to validate 10 fields.How do i change your code.

Roman Over a year ago

empty fields don't match your regex, so it will treat that as an error. To add a field, you have to add an array to $validate, just like the 2 that are already there.

|

Community · Accepted Answer · 2023-11-17 20:11:10Z

1

Use filter_var functions. You have the options you need there.

edited Nov 17, 2023 at 20:11

CommunityBot

11 silver badge

answered Jun 19, 2012 at 8:40

Elzo Valugi

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2 Comments

user1415759 Over a year ago

:I'm using php 4,it is only supported for PHP 5.

Elzo Valugi Over a year ago

I don't see ANY reason to use php4 in 2012, even for legacy code. PHP5 was released in 2005. PHP4 is not supported and a security risk.

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