Mailer component and html() call -incompatible with simple_html_dom library ?

[simogeo]

Symfony version(s) affected

5.4.38

Description

I'm trying to switch from swiftMailer to symfony/mailer used as external library ( I don't use symfony)

Everything works well except when I send html manipulated with simple_html_dom library, I get the following error :

Fatal error: Uncaught TypeError: The body must be a string, a resource or null (got "simple_html_dom"). in lib/comp-vendor/symfony/mime/Email.php:321 Stack trace: #0 mail/send.php(127): Symfony\Component\Mime\Email->html() #1 plugins/l21_emailSuite/index.php(46): send_email() #2 plugins/index.php(56): include_once('...') #3 templates/admin/2021/index.php(72): include_once('...') #4 admin/index.php(74): include_once('...') #5 {main} thrown in lib/comp-vendor/symfony/mime/Email.php on line 321

When I pass the

If I send row html (with no simple_html_dom library anterior manipulation, I do not experience any issue ... I guesse this is related to mime type ... but I'm stuck. Do you have any clue ?

Thanks in advance,

How to reproduce

• prepare a mail with html content using symfony/mailer
• do manipulate html content with simple_html_dom library available at http://sourceforge.net/projects/simplehtmldom/
• try to send the mail, it will trigger an error similar to the one provided above

Possible Solution

No response

Additional Context

I know simple_html_dom is an old library ! but quite useful ... should symfony/mailer be more permissive ?

[simogeo]

By the way, it seems I get a similar result when using https://github.com/voku/simple_html_dom

[simogeo]

For your information, a workaround is to cast variable to string

This generates an error :

$message = (new Email())
				->from(new Address($from, $fromname))
				->subject($email['subject'])
				->text($email['txt_body'])
				->html($email['html_body']);

and this works :

$message = (new Email())
				->from(new Address($from, $fromname))
				->subject($email['subject'])
				->text($email['txt_body'])
				->html((string) $email['html_body']);

[simogeo]

The question is : should symfony/mailer try to cast the passed variable itself ?

[mbabker]

No, it shouldn't.

The framework tells you the types of information that the method supports and raises an error if you pass in something it doesn't support. The framework magically casting unsupported types may or may not result in unexpected behavior, so it is better for it to raise an error on an unsupported type.

In your case, the (string) $email['html_body'] bit works because you're working with an object that has a magic __toString() implementation, and what that magic method provides is exactly what you need for your HTML email body. There is no guarantee the same can be said for other objects with this magic method.

You know what type of information you are working with within the context of your application, and you know what type of information the third-party code you're calling needs. Your application code is best able to handle converting data into what the third-party code needs versus relying on the third-party code to try and create something that may or may not be appropriate for its use.