Form validation without deleting the fields?

[NikosDim]

Hi to everyone

 

I have implemented a html form with some fields like email and phone and I want to validate the data before submitting the form. I want to validate the data in the server side (because javascript can be easily avoided) and so I have write some PHP functions. Currently the form is in a Form.html file and the validation script is in a Validate.php file.

 

If I the validation of the data return false how can I return to my form WITHOUT the fields to be erased?

 

Thanks

[Pikachu2000]

Google 'php sticky forms'.

[peipst9lker]

You can do it in 2 different ways

 

Way 1

Whenever a formfield looses focus you do an AJAX-request to some kind of validation.php (GET/POST parameter for the type and value of the field)

If u go that way I'd rather write ur own jQuery Extension for this (kinda easy)

 

Way 2

Use a client-side and a server-side validation. 1 Javascript which watches your fields and when the data is sent your PHP script checks everything again (incase someone just turns off JavaScript or modifies the request)

[hakimserwa]

this guy explained this better atleast easy to understand.  look for this section or read the whole post.

"""Prevent Inputs from Clearing After an Error""

http://buildinternet.com/2008/12/how-to-validate-a-form-using-php-part-2-streamline-using-arrays/

[peipst9lker]

Echo the sent GET/POST variables (escape them to avoid XSS-vulnerabilities) into the value-attribute and you're done?

[hakimserwa]

Echo the sent GET/POST variables (escape them to avoid XSS-vulnerabilities) into the value-attribute and you're done?

 

we learn new things every day can you please show as how?

[peipst9lker]

Very very very basic example

 

<form action="example.php" method="POST">
<input type="text" name="example" value="<?php echo (isset($_POST['example'])) ? htmlentities($_POST['example']) : ''; ?>" />
</form>

[NikosDim]

Thank you very much for your answers. I will try what you told me. I hope everything will go well!

[hakimserwa]

welcome

[NikosDim]

One last thing. In my form I have some <select> elements with many many options. In order to make the <select> fields to have the values before submission I have to put a small code snippet like this below in each option?

 

<option value='option_value'<?php echo (isset($_POST['selectname']) && $_POST['selectname'] == 'option_value')?  "selected='selected'" : '' ; ?>> option_text </option>

 

Thanks

[peipst9lker]

One last thing. In my form I have some <select> elements with many many options. In order to make the <select> fields to have the values before submission I have to put a small code snippet like this below in each option?

 

Yes you have, but I'd rather create option-tags via loop.

Another little tip for you, always put html-attributes in ""-quotes not single ones.

 

// somwhere on top of the script
$options = array(1 => 'Cheeseburger', 2 => 'Hamburger', 3 => 'BigMac');
$selected = $_POST['selectname'];

// inside your <select>
foreach ($options as $val => $option)
echo (isset($selected) && $val == $selected) ? '<option value="'.$val.'" selected="selected">'.$option.'</option>' : '<option value="'.$val.'" >'.$option.'</option>';

[cyberRobot]

Another little tip for you, always put html-attributes in ""-quotes not single ones.

 

 

Beyond personal preference, what's wrong with single quotes? Note that I prefer double quotes for HTML attributes. However I'll usually use single quotes when those attributes are within a double-quoted PHP string.

[NikosDim]

 

Yes you have, but I'd rather create option-tags via loop.

Another little tip for you, always put html-attributes in ""-quotes not single ones.

 

 

Thanks peipst9lker. I created option with a foreach loop as you said. It was easy!!!

I will ask the same thing as cyberRobot did.

What is the difference on putting double quotes in the html-attributes?

[peipst9lker]

There is no technical difference - it's just to have everything in the same pattern and not mixed up code.

I'm very very used to it since in c/c++ single quotes are char-variables and double quotes are strings (or char[]'s) also it's part of my companys coding standard. It's just stored in my DNA already

[hakimserwa]

 

Yes you have, but I'd rather create option-tags via loop.

Another little tip for you, always put html-attributes in ""-quotes not single ones.

 

 

Thanks peipst9lker. I created option with a foreach loop as you said. It was easy!!!

I will ask the same thing as cyberRobot did.

What is the difference on putting double quotes in the html-attributes?

 

keeping it easy and simple so in somewhile to someone going through your code can understand easily. lets say good coding practice.