Twilio\TwiML\Voice\Dial::setAnswerOnBridge and other XML boolean attributes should be rendered as strings "true" and "false"

[stevebauman]

Issue Summary

We've been instructed by your support that the XML attribute (and all other boolean attributes on TwiML verbs) should be output in XML content as "true" and "false", not as 1 and 0, as your PHP API suggests inside of its doc blocks when using the suggested bool types:

Code Snippet

This behaviour occurs when you pass a PHP boolean into your PHP API in any of the verb functions:

twilio-php/src/Twilio/TwiML/Voice/Dial.php

Lines 202 to 210 in 793917c

	/**
	* Add AnswerOnBridge attribute.
	*
	* @param bool $answerOnBridge Preserve the ringing behavior of the inbound
	* call until the Dialed call picks up
	*/
	public function setAnswerOnBridge($answerOnBridge): self {
	return $this->setAttribute('answerOnBridge', $answerOnBridge);
	}

use Twilio\TwiML\VoiceResponse;

$response = new VoiceResponse();

$dial = $response->dial('...');

$dial->setAnswerOnBridge(true);

Output:

<?xml version="1.0"?>
<Response>
  <Dial answerOnBridge="1" ...>
    <Number>+15552345678</Number>
  </Dial>
</Response>

Technical details:

• twilio-php version: 6.44.4
• php version: 8.2.14

---

Can you please confirm whether this is actually the case whether or not this matters on your backend? If so, these doc blocks should all be adjusted, or have the boolean values be casted to raw strings automatically prior to being output in the XML.