Add DebugOutput setter function

[Bankde]

Having DebugOutput setter will give developers ability to create their own error handle function which can be very useful.

[ivantcholakov]

Hello, @Bankde ,

Please, see this line at PHPMailer:
https://github.com/PHPMailer/PHPMailer/blob/v5.2.26/class.phpmailer.php#L663
By default PHPMailer detects CLI and sets the option accordingly.

CodeIgniter detects CLI this way: https://github.com/bcit-ci/CodeIgniter/blob/3.1-stable/system/core/Common.php#L381

Therefore, for not breaking backward compatibility I would prefer the default configuration option to have this value:

$config['debug_output']     = (PHP_SAPI === 'cli' OR defined('STDIN')) ? 'echo' : 'html'; // PHPMailer's SMTP debug output: 'html', 'echo', 'error_log' or user defined function with parameter $str and $level.

Do you agree? If yes, you can add this change to this PR, or I can accept this PR as it is and make the change later.

[ivantcholakov]

@Bankde

Since there is a newer version of PHPMailer and I hurry, I would merge this PR as it is and implement my suggestion. You can always customize the default value in your projects.

Thank you very much for your contribution.

[Bankde]

I completely agree with you. I forgot that codeigniter could be run on CLI. Have you start implementing your suggestion yet ?

I have a problem with modifying static default_properties.
Since PHPMailer can already detect CLI, I think I will remove default from library and let PHPMailer detects it alone. For the code in config, I will put the CLI detection there. Is that good ?

[ivantcholakov]

I researched a little bit, for this particular case, I think

$config['debug_output']     = (strpos(PHP_SAPI, 'cli') !== false OR defined('STDIN')) ? 'echo' : 'html';

would be a better choice.

https://www.sitepoint.com/taking-advantage-of-phps-built-in-server/

PHP_SAPI could return 'cli' or 'cli-server', for both of these cases I would set 'echo' as PHPMailer does.

Let me do the changes and I would ask you for comments.

[Bankde]

Just a reminder, don't forget to fix debug_output from $default_properties.
We could just remove it in PHPMailer 5.2.26, otherwise we will have to set default debugoutput in the constructor.

[ivantcholakov]

Actually, I used the constructor to enforce the autodetection. I think this part of code is finished now.

[ivantcholakov]

@Bankde

If you have no objections I am going to make my usual testing and to tag a new release 1.2.26.

[Bankde]

The code looks great. I have no objections here.

[ivantcholakov]

Done. Thank you once again. :-)