如何在联系表单中阻止文本区域上的 URL？

Question

I'm receiving some unwanted links though the contact form, how to restrict the user or bot to enter URL link on the textarea?

I have done so many google searches but none of them worked for me, tried some libraries too like jquery validation but I couldn't find the solution for this.

Answer 1

You could simply have a list of "banned" URLs and check if any are included in the value of the textarea.

 const textarea = document.getElementById('textarea'); const errorP = document.getElementById('error'); const bannedUrls = [ 'google.com', 'reddit.com', 'stackoverflow.com', ]; textarea.addEventListener('input', () => { const bannedUrlsInInput = bannedUrls.filter(url => textarea.value.includes(url)); if (bannedUrlsInInput.length > 0) { errorP.textContent = `${bannedUrlsInInput.join(', ')} not allowed`; } else { errorP.textContent = ''; } });

 <textarea id="textarea" rows="10" cols="80"></textarea> <p id="error"></p>

Note that this is not the most performant way. If you have thousands of banned domains, you should consider using the exotic Bloom filter data structure.

And last but not least -- if this validation is truly critical, it is not enough to just do client side validation, you need some server validation too.

Answer 2

You can use preg_match

if($_POST){
 !preg_match(^(https?:\/\/)?(www\.)?\w+\.[a-z]{2,6}(\/)?$, $_POST);
 $error = 'links are not allowed';
return $error;
}