Error when using <?php tag inside the processing text

[Coackroach]

Prerequisites

• I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• The issue still exists against the latest master branch of yii2-markdown.
• This is not a usage question. I confirm having gone through and read the documentation and demos.
• This is not a general programming/coding question. (Those should be directed to the webtips Q & A forum).
• I have attempted to find the simplest possible steps to reproduce the issue.
• I have included a failing test as a pull request (Optional).

Steps to reproduce the issue

1.Install the extension
2.crate a readme.md file and add the following containing the <?php tag

<?php echo "some text"

3. Convert the text using

echo Markdown::process($this->render('README.md'));

Expected behavior and actual behavior

When I follow those steps, I see...

PHP Parse Error – yii\base\ErrorException
syntax error, unexpected '`'

I was expecting...
The formatted output

If you remove the <?php tag from the text to be processed then it works ok

BUT

If you use it in the following way it even works along the <?php tag

<?php $html = <<< HTML
        <?php echo "some text";
HTML;
?>
<?=\kartik\markdown\Markdown::process($html) ?>

Environment

Yii 2.0.15.1

Browsers

• Google Chrome
• Mozilla Firefox
• Internet Explorer
• Safari

Operating System

• Windows
• Mac OS X
• Linux
• Mobile

Libraries

• jQuery version:
• yii2-markdown version:

Isolating the problem

• This bug happens on the demos page
• The bug happens consistently across all tested browsers
• This bug happens when using yii2-markdown without other plugins.

[Kartik Visweswaran]

Use Html::encode on the text before you process using Markdown::process.

[Coackroach]

@kartik-v Well to my surprise the Html::encode() does not solve the issue, instead you have to provide the closing ?> tags along with the starting tags to make it work correctly when using $this->render('README.md') to load the text.