How to get absolute file system path to an image Symfony2/Twig

Question

I am using Symfony2 with twig to generate HTML, however the HTML I am generating is not intended for a web browser, instead it will be passed to a library that converts HTML to a PDF document.

There are two related issues I am facing.

Issue 1. This PDF will have images included, I don't want these images to be visible directly from the internet (e.g. I don’t want these images to appear under webroot). Usually I put assets in “site/src/path-to-bundle/Resources/public/assets” however, I don't want this image to be visible on the web. Can anyone suggest a good folder to put “assets” in that are not meant to be accessible via the web. (Just trying to be consistent with Symfony2 naming techniques and how other programmers would usually do this)

Issue 2. Since the HTML I am generating is intended for the HTML to PDF generator, it is most practical to refer to images with absolute paths on the file system (web paths or URLs are not suitable in this situation).

For example

<!-- This is the correct HTML code that is needed in this situation -->
<img src="/home/user/absoulte-file-system-path-to/image.png" />

<!-- These are actually incorrect in this situation -->
<img src="assets/image.png" />
<img src="http://www.somedomain.com/assets/image.png" />

I would like to know how to get the absolute path to the image mentioned above (I don’t mind if this is done in the Twig template or in the controller)

Answer 1

in you app/config/config.yml

twig:
    globals:
        root_path: %kernel.root_dir%

and you can refer to asset with relative path to your root project

 <img src="{{ root_path }}/../secret-folder/image.png" />