media objects disappear after a reload

[andrewscofield]

So, I recently learned about the global media object and tried to use it to pull images from my theme and found a bug in it. I'm not sure if I'm using it wrong or what the deal is. But here are repeatable steps you can do to reproduce it, I just tested this out on a clean develop branch.

1. clone develop branch
2. run bin/grav install
3. on the antimatter theme add a media object to templates/default.html.twig like so:

{% extends 'partials/base.html.twig' %}

{% block content %}
	{{ media['theme://images/logo.png'].html() }}
	{{ page.content }}
{% endblock %}

4. Load page of the fresh install - notice the logo on top.
5. Reload the page - logo is gone.
6. Clear cache in admin
7. Reload the page - logo is back.

[rhukster]

Ok, a point of confusion here that is probably to blame. There's a media twig variable that is made available in the processPage() and processSite(). This is a convenience variable that simply points to $page->media() which returns an array of the page's media.

So if you access media['somefile.jpg] you are using that.

However, there's also a a media() twig function that lets you use streams such as the example above. This is not directly conflicting with the media variable, as the variable is an array and this is a function, but if you use [] you are using the variable, and if you use () you are using the function. I think the solution to your issues is to use () like:

{{ media('theme://images/logo.png').html() }}

[andrewscofield]

Ooh, ok this make sense. But I am unable to get the image to show up at all if I change it to a media function though.

And I did get my info and that snippet from the docs:

https://learn.getgrav.org/themes/theme-vars#media-object

So maybe its wrong there too?

[rhukster]

Well, i can reproduce the issue so i'm going to dig in!

[rhukster]

@mahagr any ideas on this one.. seems the Twig is just losing all reference to this once cached...

[mahagr]

This seems to be a hard one. The entry that causes this issue is the doctrine cached item for Page\Media.

[mahagr]

Found it out. Media object was serialized, but unserialization was incomplete.

[andrewscofield]

Awesome that you guys were able to find the bug!

Getting back to my question about the docs, is it correct to use media['theme://images/logo.png'] like the docs say, or is it supposed to be media('theme://images/logo.png') ? From the first reply by @rhukster it seems like the docs are wrong, but currently media() doesn't work for me at all

[rhukster]

The docs are correct. I renamed the media() twig function which actually works on a directory to media_directory() to avoid confusion.

[klihelp]

How media_directory() works? Gives me this error

 Twig_Error_Runtime
An exception has been thrown during the rendering of a template ("Object of class Grav\Common\Page\Media could not be converted to string").