Keyword checking in Gravity Forms

Question

Keyword checking in Gravity Forms

bushrang

2022年5月12日 10:00

In Gravity Forms I'd like to include a small keyword checker that is checking the user's message for "spammy" words and stops sending the entry to the admin. For this a hidden field changes it's value. I have this code included in my functions.php so far

function strpos_arr($haystack, $needle) {
if(!is_array($needle)) $needle = array($needle);
foreach($needle as $what) {
    if(($pos = stripos($haystack, $what))!==false) return $pos;
}
return false;
}

/*
* Our bad words validation function
*/


add_action('gform_pre_submission_1', 'keywords_check'); 

function keywords_check($validation_result){
$form = $validation_result["form"];


$stop_words = array(
    'outsource', 
    'Madam', // this covers all variations of 'Sir/Madam' 'Sir /Madam' 'Sir/ Madam' 'Sir / Madam' etc
    'SEO',
    'long term relationship',
);

$stop_id = array();

foreach($_POST as $id = $post)
{
    if(strpos_arr($post, $stop_words))
    {
        /*
         * We have a match so store the post ID so we can count it
         */ 
         $stop_id[] = $id;
    }
}

if(sizeof($stop_id)  0)
{
    $validation_result['is_valid'] = false;


    $_POST['input_55'] = "No";

}

}

There seems to be a problem with the part in the very beginning of this code, especially with

foreach($needle as $what) {
    if(($pos = stripos($haystack, $what))!==false) return $pos;
}

After sending the form I get the following warning

Warning: stripos() expects parameter 1 to be string, array given on line 109

I have several php noob trial and error hours behind me before asking this question. Can anyone help me out with this?

Topic plugin-gravity-forms functions php Wordpress

Category Web

Anthony D · Accepted Answer · 2019年11月15日 19:06

I would suggest an addition to Frank P. Walentynowicz's answer. Make it so you will not need to constantly edit your functions.php when you want to add/remove to the $stop_words array.

You can achieve this by utilizing the built-in Wordpress Comment Blacklist feature.

Everything you save in the wp blacklist is stored in the database in the WP_Options table under blacklist_keys. https://codex.wordpress.org/Option_Reference

At the start of your keywords_check function you can get these keys and store them in a variable:

$blacklisted = get_option('blacklist_keys');

Now, turn those into a proper array:

$stop_words = preg_split("/[\s,]+/", $blacklisted);

All the stop words will be pulled from the WP blacklist. You can continue the rest of the function as detailed in Frank's answer. Even a non-developer can help filter spam right from the Wordpress dashboard.

Here it is all together:

function strpos_arr($haystack, $needle) {
    if(!is_array($needle)) $needle = array($needle);
    foreach($needle as $what) {
        if(($pos = stripos($haystack, $what))!==false) return true;
    }
    return false;
}
add_action('gform_pre_submission_1', 'keywords_check');

function keywords_check( $result, $value, $form, $field ) {
    $blacklisted = get_option('blacklist_keys');
    $stop_words = preg_split("/[\s,]+/", $blacklisted);

    if ( strpos_arr( $value, $stop_words ) ) {
        $result['is_valid'] = false;
        $result['message'] = 'Illegal words entered';
    }
    return $result;
}
add_filter( 'gform_field_validation_2_4', 'keywords_check', 10, 4 );

If you don't need to test a particular form field like this answer details, I have a solution that will test the WP Comment blacklist against all form fields.

GitHub link below: https://github.com/adaprile/Gravity-Forms-WP-Comment-Blacklist

I hope this helps someone!

Frank P. Walentynowicz · Accepted Answer · 2017年5月22日 18:49

The problem is in function strpos_arr. If your bad word is in $pos = 0 than the output will always be false. Replace the line:

if(($pos = stripos($haystack, $what))!==false) return $pos;

with:

if(($pos = stripos($haystack, $what))!==false) return true;

Your keywords_check function can be much simplified by using it as Gravity Forms field validation filter:

function keywords_check( $result, $value, $form, $field ) {
    $stop_words = array(
        'outsource', 
        'Madam', // this covers all variations of 'Sir/Madam' 'Sir /Madam' 'Sir/ Madam' 'Sir / Madam' etc
        'SEO',
        'long term relationship',
    );

    if ( strpos_arr( $value, $stop_words ) ) {
        $result['is_valid'] = false;
        $result['message'] = 'Illegal words entered';
    }
    return $result;
}
add_filter( 'gform_field_validation_2_4', 'keywords_check', 10, 4 );

Notice two numbers in 'hook' name in this example. 2 - form id, 4 - field id. Adjust those numbers to match your form.

Dave from Gravity Wiz · Accepted Answer · 2017年5月22日 00:52

1

Dave from Gravity Wiz answered at 2017年5月22日 00:52

I have a plugin that will also handle this via the default WordPress comment blacklist functionality: https://gravitywiz.com/documentation/gravity-forms-comment-blacklist/

Keyword checking in Gravity Forms

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