# Code to ban URLs in form fields now triggers fatal error

**URL:** <https://community.gravityforms.com/t/code-to-ban-urls-in-form-fields-now-triggers-fatal-error/14111>\
**Category:** Get Help\
**Tags:** gform\_field\_validation\
**Created:** [December 19, 2022, 11:23pm UTC](https://community.gravityforms.com/t/code-to-ban-urls-in-form-fields-now-triggers-fatal-error/14111 "2022-12-19T23:23:10Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Trisha](https://sea2.discourse-cdn.com/flex020/user_avatar/community.gravityforms.com/trisha/32/1977_2.png) [@Trisha](https://community.gravityforms.com/u/Trisha)\
**Post date:** [December 19, 2022, 11:23pm UTC](https://community.gravityforms.com/t/code-to-ban-urls-in-form-fields-now-triggers-fatal-error/14111/1 "2022-12-19T23:23:10Z")

</div>

For years I have used some code given by GF that prevents form submissions if URLs are included in specific (or any) form fields (to stop spam bots), but it has suddenly stopped working and now triggers a fatal error:

**Fatal error** : Uncaught TypeError: preg\_match(): Argument #2 ($subject) must be of type string, array given in […]

Here is the code I was given, the line that is triggering the error is the one that starts with "if ( $result[‘is\_valid’] "

```auto
add_filter( 'gform_field_validation', 'custom_validation', 10, 4 );
function custom_validation( $result, $value, $form, $field ) {

	if ( $result['is_valid'] && preg_match('/\b(?:(?:https?|ftp|http):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i', $value ) ) {
		$result['is_valid'] = false;
		$result['message'] = 'Please remove URLs';
	}
	return $result;
}

```

I found _very similar_ code here that also does not work (triggers the same error):  
[https://community.gravityforms.com/t/how-to-block-link-tags-and-urls-hyperlinks-contained-in-any-form-field-regex-format-resolved/13787](https://community.gravityforms.com/t/how-to-block-link-tags-and-urls-hyperlinks-contained-in-any-form-field-regex-format-resolved/13787)

Is there an updated way to stop users from submitting hyperlinks in form fields?

I am using the most current version of Gravity Forms with WP ver. 6.1.1 and PHP 8.0.

Any help would be appreciated!

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<div class="post-metadata">

**Author:** ![chrishajer](https://sea2.discourse-cdn.com/flex020/user_avatar/community.gravityforms.com/chrishajer/32/88_2.png) [@chrishajer](https://community.gravityforms.com/u/chrishajer)\
**Post date:** [December 20, 2022, 9:08pm UTC](https://community.gravityforms.com/t/code-to-ban-urls-in-form-fields-now-triggers-fatal-error/14111/2 "2022-12-20T21:08:10Z")

</div>

There was probably a change in PHP 8 that causes a fatal error now. If you are checking all fields for URLs, you are probably checking some fields that return an array rather than a string. `preg_match` is looking for a string.

You will need to narrow the focus so that this validation filter only applies to specific fields in specific forms, or you will need to do more work to convert the parts of the array of values to string so the original function can work.

To apply to specific fields in one form, you could do this:

```auto
add_filter( 'gform_field_validation_8_2', 'custom_validation', 10, 4 );
add_filter( 'gform_field_validation_8_5', 'custom_validation', 10, 4 );
add_filter( 'gform_field_validation_8_6', 'custom_validation', 10, 4 );
add_filter( 'gform_field_validation_8_20', 'custom_validation', 10, 4 );
function custom_validation( $result, $value, $form, $field ) {
	if ( $result['is_valid'] && preg_match('/\b(?:(?:https?|ftp|http):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i', $value ) ) {
		$result['is_valid'] = false;
		$result['message'] = 'Please remove URLs';
	}
	return $result;
}

```

That would apply to fields 2, 5, 6, and 20 in form 8.

You could also change the code to check the field type before trying to validate. Something like this:

```auto
add_filter( 'gform_field_validation', 'custom_validation', 10, 4 );
function custom_validation( $result, $value, $form, $field ) {
	// check text fields and textareas for URLs
	if ( 'text' === $field->type || 'textarea' === $field->type ) {
		if ( $result['is_valid'] && preg_match('/\b(?:(?:https?|ftp|http):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i', $value ) ) {
			$result['is_valid'] = false;
			$result['message'] = 'Please remove URLs';
		}
	}
	return $result;
}

```

---

<div class="post-metadata">

**Author:** ![Trisha](https://sea2.discourse-cdn.com/flex020/user_avatar/community.gravityforms.com/trisha/32/1977_2.png) [@Trisha](https://community.gravityforms.com/u/Trisha)\
**Post date:** [December 20, 2022, 9:19pm UTC](https://community.gravityforms.com/t/code-to-ban-urls-in-form-fields-now-triggers-fatal-error/14111/3 "2022-12-20T21:19:50Z")

</div>

Got it, and thank you!!

Your explanation makes perfect sense. In our case, the bots and other (live?) spammers routinely fill the “message” field (textarea) with hyperlinks…so I will be sure to target _just those_ textareas.

🙂 and hugs,  
Trisha

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<div class="post-metadata">

**Author:** ![chrishajer](https://sea2.discourse-cdn.com/flex020/user_avatar/community.gravityforms.com/chrishajer/32/88_2.png) [@chrishajer](https://community.gravityforms.com/u/chrishajer)\
**Post date:** [December 20, 2022, 9:24pm UTC](https://community.gravityforms.com/t/code-to-ban-urls-in-form-fields-now-triggers-fatal-error/14111/4 "2022-12-20T21:24:18Z")

</div>

It will be easier then targeting only the textarea. You just need to add that check so that not all fields in the form as run through this filter, which is why there is a fatal error now (some values are not strings but arrays.)

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex020/uploads/gravityforms1/original/2X/f/fef63f0599c45e0218c30d9f5d7ca8bff9b00189.png) [@system](https://community.gravityforms.com/u/system)\
**Post date:** [December 21, 2022, 9:24pm UTC](https://community.gravityforms.com/t/code-to-ban-urls-in-form-fields-now-triggers-fatal-error/14111/5 "2022-12-21T21:24:27Z")

</div>

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