Using an array

[dmsman]

I need to use PHP on my WordPress site to restrict who can submit a specific form. I only want to allow those using a specific email domain to be able to submit a form. Below is the code I am using. The code works. The issue is I have 400+ domains that I need to whitelist. I am hoping to use an array but I don't know if this is the best way. Bottom line is I am hoping someone can help adjust the code below to show me how to add additional domains. In the code below, the only domain currently whitelisted is example.com.

add_filter('frm_validate_field_entry', 'check_valid_email', 10, 3);
function check_valid_email($errors, $posted_field, $posted_value){
 if($posted_field->id == 7){
     $postedemail=$_POST['item_meta'][7];
	  $alloweddomain = explode('@',$postedemail)[1];
	 if (!filter_var($postedemail, FILTER_VALIDATE_EMAIL) || $alloweddomain != 'example.com') {
       $errors['field'. $posted_field->id] = 'Sorry! You are not allowed to submit this form';
   }
 }
return $errors;
}

[ginerjm]

I would choose a db table instead of an array.  That way when you have to make additions or removals it's a simple update to a table rather than a coding exercise.

[kicken]

Create your array of domains, then use the in_array function to check if $alloweddomain is contained in that array.

[dmsman]

I should have mentioned that I don't know how to code PHP. Formidable Forms provided the original PHP code which I tweaked to work my specific forms. @kicken, I like what you're saying however I don't know what code to write. If this requires a paid project, I'm happy to do that however I need guidance and almost copy-and-paste code.

[Barand]

The easiest way to maintain your list of whitelisted domains is just to list them in a plain text file, say, whitelist.txt

domain1.com
domain2.com
domain3.com
...
domain400.com

Then use the file() function to load them into your whitelist array.

<?php
    $whitelist = file('whitelist.txt', FILE_IGNORE_NEW_LINES);
    
    if (in_array($userDomain, $whitelist)) {
        // use the domain
    }
    else {
        // reject domain
    }
?>