PHP Form Validation,how to make form invisible

Question

I am performing a Form Validation in PHP. My purpose is to show the error message at the same page with form, in order to be clear for the user.

But I have to problems. First how to hide my form, where are no errors in submitting it(I want to print onl one message in this case and to hide the frm). I am trying to use:

if(false === $error)
        {
            //Validimi perfundoi me sukses!

            echo "<script> 
                document.getElementById('wrap').style.display = 'none';
        </script>";

         echo $name;
        }

but it does not function.

Second I am having problems with checkbox validation. I am using the array $activity, to save values from checkbox, as they may be multiple values, but when the user select no value at all at the checkbox part, it gives me the error that: Warning: in_array() expects parameter 2 to be array, null given even i have initialized $activity as an arra: $activity=array();.

<?php
$name_error='';
$device_error ='';
$OS_error='';
$activity_error='';
$device='';
$OS='';
$activity=array();
if(!empty($_POST['submitted']))
{//nese form eshte submitted atehere validohen fushat
    $name = trim($_POST['name']);//heq hapesirat
    $error = false;

    if(empty($name))
    {
        $name_error='Emri eshte bosh. Ju lutem plotesoni emrin.';
        $error=true;
    }

    if(empty($_POST['device']))
    {
        $device_error = "Ju lutem selektoni nje pajisje";
        $error=true;
    }
    else
    {
        $device = $_POST['device'];
    }

    if(empty($_POST['OS']))
    {
        $OS_error ="Ju lutem selektoni sistemin operativ";
        $error=true;
    }
    else
    {
        $OS = $_POST['OS'];
    }

    if(empty($_POST['activity']) || count($_POST['activity']) < 2)
    {
        $activity_error = "Ju lutem selektoni te pakten 2 aktivitete";
        $error=true;
    }

    $activity = $_POST['activity'];

    if(false === $error)
    {
        //Validimi perfundoi me sukses!

        echo "<script> 
            document.getElementById('wrap').style.display = 'none';
    </script>";

     echo $name;
    }
}
?>
<!DOCTYPE html>
<html >
<head>
    <title>Computer Form</title>
    <link href="compForm.css" rel="stylesheet" type="text/css" />
</head>
<body >
    <div id="wrap" style="display: block">
        <form method="post" action='?' id="compform" >
        <div>
            <div class="cont_order">
               <fieldset>
               <legend>Beni zgjedhjen tuaj!</legend>
                <div class='field_container'>
                <label >Zgjidhni pajisjen qe perdorni me shpesh:</label>
                <span class="error"><?php echo $device_error;?></span>
                <label class='radiolabel'><input type="radio"  name="device" value="Desktop"  
                <?php echo ($device=='Desktop')? 'checked':''; ?>/>Desktop</label><br/>
                <label class='radiolabel'><input type="radio"  name="device" value="Laptop" 
                <?php echo ($device=='Laptop')? 'checked':''; ?> />Laptop</label><br/>
                <label class='radiolabel'><input type="radio"  name="device" value="Tablet" 
                <?php echo ($device=='Tablet')? 'checked':''; ?> />Tablet</label><br/>
                </div>


                <div class='field_container'>
                    <label for="OS">Zgjidhni Sistemin e Operimit qe perdorni:</label >
                    <span class='error'><?php echo $OS_error?></span>
                    <select id="OS" name='OS' >
                    <option value="">Zgjidhni OS</option>
                    <option <?php echo $OS=='Windows'?'selected':''; ?> >Windows</option>
                    <option <?php echo $OS=='Linux'?'selected':''; ?> >Linux</option>
                    <option <?php echo $OS=='Mac'?'selected':''; ?> >Mac</option>
                   </select>
                </div>

                <div class='field_container'>
                    <label >Selektoni dy aktivitetet qe preferoni me shume:</label>
                    <span class='error'><?php echo $activity_error ?></span>
                    <label><input type="checkbox" value="Programim Desktop" name='activity[]'
                    <?php echo (in_array('Programim Desktop',$activity)) ?'checked':'' ?>  />Programim Desktop</label>
                    <label><input type="checkbox" value="Programim Web" name='activity[]' 
                    <?php echo (in_array('Programim Web',$activity)) ?'checked':'' ?> />Programim Web</label>
                    <label><input type="checkbox" value="Dizenjim" name='activity[]' 
                    <?php echo (in_array('Dizenjim',$activity)) ?'checked':'' ?> />Dizenjim</label>
                    <label><input type="checkbox" value="Analize te dhenash" name='activity[]' 
                    <?php echo (in_array('Analize te dhenash',$activity)) ?'checked':'' ?> />Analize te dhenash</label>
                    <label><input type="checkbox" value="Kerkim shkencor" name='activity[]' 
                    <?php echo (in_array('Kerkim shkencor',$activity))?> />Kerkim shkencor</label>
               </div>

              </fieldset>
            </div>


            <div class="cont_details">
                <fieldset>
                <legend>Detajet e kontaktit</legend>
                <label for='name'>Emri</label>
                <input type="text" id="name" name='name' 
                value='<?php echo htmlentities($name) ?>' />
                <span class='error'><?php echo $name_error ?></span>
                <br/>
                <label for='address'>Adresa e emailit</label>
                <input type="email" id="address" name='address' />
                <br/>
                </fieldset>
            </div>

         <input type='submit' name='submitted' id='submit' value='Submit'  />
        </div>  
       </form>
    </div>

</body>
</html>

How to check if checkbox array is set http://stackoverflow.com/questions/4554758/how-to-read-if-a-checkbox-is-checked-in-php the accepted answer and rybo111's answer Remember to use `htmlspecialchars()` on any user input you will echo to prevent script attack. — Steve, Jan 24 '16 at 06:06
The errors are coming from `echo (in_array('Programim Web',$activity)) ?'checked':''` etc, where you need to add the `isset()` to those too, so you don't do the `in_array()` on it if it is empty. — Steve, Jan 24 '16 at 06:52
Another way to approach using the value is to have your expected responses in an array and only have numerical values in your HTML in dropdowns or checkboxes/radio buttons. Then you only need to use `intval($_POST['your_submitted_number']);` which effectively sanitises it by forcing integer value (anything else will come out as 0). http://stackoverflow.com/questions/34812089/selecting-default-value-in-html-dropdown-list/34817939#34817939 and http://stackoverflow.com/questions/34361452/many-elements-of-a-listbox-to-another/34367418#34367418 as examples. Glad that worked for you. — Steve, Jan 24 '16 at 17:36

Mikey · Accepted Answer · 2016-01-24T07:16:29.560

Here's my quick solution (untested). Let's clean up your code a little:

Instead of using (and wasting) separate variables for each error message, let's use an associative array called $errors. The keys will be the name of the inputs and the values will be their respective error messages.
To ensure that you don't get warnings from undeclared variables, we will declare variables for each input at the top of the page.
Let's also use a new variable $submitted to know whether the form was submitted or not.

Now, if the form was $submitted and there are no (!) $errors, then we hide the form. Otherwise, we show the form and any errors if there are any.

<?php
$name = '';
$device = '';
$OS = '';
$activity = array();
$submitted = !empty($_POST['submitted']);
$errors = array();

if ($submitted) {
    //nese form eshte submitted atehere validohen fushat
    if (empty($_POST['name'])) {
        $errors['name'] ='Emri eshte bosh. Ju lutem plotesoni emrin.';
    } else {
        $name = trim($_POST['name']);
    }
    if (empty($_POST['device'])) {
        $errors['device'] = "Ju lutem selektoni nje pajisje";
    } else{
        $device = $_POST['device'];
    }
    if (empty($_POST['OS'])) {
        $errors['OS'] = "Ju lutem selektoni sistemin operativ";
    } else {
        $OS = $_POST['OS'];
    }
    if (empty($_POST['activity']) || count($_POST['activity']) < 2) {
        $errors['activity'] = "Ju lutem selektoni te pakten 2 aktivitete";
    } else {
        $activity = $_POST['activity'];
    }
}
?>
<!DOCTYPE html>
<html >
<head>
    <title>Computer Form</title>
    <link href="compForm.css" rel="stylesheet" type="text/css" />
</head>
<body>
<?php if ($submitted && !$errors) : ?>
    <?php echo $name ?>
<?php else : ?>
    <div id="wrap">
        <form method="post" action='?' id="compform" >
        <div>
            <div class="cont_order">
               <fieldset>
               <legend>Beni zgjedhjen tuaj!</legend>
                <div class='field_container'>
                    <label >Zgjidhni pajisjen qe perdorni me shpesh:</label>
                    <span class="error"><?php echo isset($errors['device']) ? $errors['device'] : '' ?></span>
                    <label class='radiolabel'><input type="radio" name="device" value="Desktop"  
                    <?php echo $device == 'Desktop' ? 'checked' : '' ?>/>Desktop</label><br/>
                    <label class='radiolabel'><input type="radio" name="device" value="Laptop" 
                    <?php echo $device == 'Laptop' ? 'checked' : '' ?> />Laptop</label><br/>
                    <label class='radiolabel'><input type="radio" name="device" value="Tablet" 
                    <?php echo $device == 'Tablet' ? 'checked' : '' ?> />Tablet</label><br/>
                </div>


                <div class='field_container'>
                    <label for="OS">Zgjidhni Sistemin e Operimit qe perdorni:</label >
                    <span class='error'><?php echo isset($errors['OS']) ? $errors['OS'] : '' ?></span>
                    <select id="OS" name='OS' >
                        <option value="">Zgjidhni OS</option>
                        <option <?php echo $OS == 'Windows' ? 'selected' : '' ?> >Windows</option>
                        <option <?php echo $OS == 'Linux' ? 'selected' : '' ?> >Linux</option>
                        <option <?php echo $OS == 'Mac' ? 'selected' : '' ?> >Mac</option>
                    </select>
                </div>

                <div class='field_container'>
                    <label >Selektoni dy aktivitetet qe preferoni me shume:</label>
                    <span class='error'><?php echo isset($errors['activity']) ? $errors['activity'] : '' ?></span>
                    <label><input type="checkbox" value="Programim Desktop" name='activity[]'
                    <?php echo in_array('Programim Desktop', $activity) ? 'checked' : '' ?>  />Programim Desktop</label>
                    <label><input type="checkbox" value="Programim Web" name='activity[]' 
                    <?php echo in_array('Programim Web', $activity) ? 'checked' : '' ?> />Programim Web</label>
                    <label><input type="checkbox" value="Dizenjim" name='activity[]' 
                    <?php echo in_array('Dizenjim', $activity) ? 'checked' : '' ?> />Dizenjim</label>
                    <label><input type="checkbox" value="Analize te dhenash" name='activity[]' 
                    <?php echo in_array('Analize te dhenash', $activity) ? 'checked' : '' ?> />Analize te dhenash</label>
                    <label><input type="checkbox" value="Kerkim shkencor" name='activity[]' 
                    <?php echo in_array('Kerkim shkencor', $activity) ? 'checked' : '' ?> />Kerkim shkencor</label>
               </div>

              </fieldset>
            </div>


            <div class="cont_details">
                <fieldset>
                    <legend>Detajet e kontaktit</legend>
                    <label for='name'>Emri</label>
                    <input type="text" id="name" name='name' value='<?php echo htmlentities($name) ?>' />
                    <span class='error'><?php echo isset($errors['name']) ? $errors['name'] : '' ?></span>
                    <br/>
                    <label for='address'>Adresa e emailit</label>
                    <input type="email" id="address" name='address' />
                    <br/>
                </fieldset>
            </div>

         <input type='submit' name='submitted' id='submit' value='Submit'  />
        </div>  
       </form>
    </div>
<?php endif ?>
</body>
</html>

Thank you @Mikey. I use some of you advices. – orsina Jan 24 '16 at 15:43 — orsina, Jan 24 '16 at 15:43

Aris · Answer 2 · 2016-01-24T08:08:19.770

0

You can check the $_POST['submitted'] as below pseudocode:

//form is submitted
if isset $_POST['submitted']
    //process form and show error message
else
    //show form

edited Jan 24 '16 at 08:08

answered Jan 24 '16 at 07:26

Aris

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PHP Form Validation,how to make form invisible

2 Answers2