Theme development

I am trying to access the field content for a view. I have been using dump, kint with varying degrees of success. I have to quit the browser each time I try something new and clear the cache. (I have correctly setup debugging in my settings etc files.
I am coming from a very strong procedural drupal background. I have studies OOP, Symfony but I am just not connecting the dots.
I have function themename_preprocess_views_view_unformatted(&$variables) {
$variables[??????????????]
}

Hi folks

Might be my first post here and I couldn't find some decent information about this so I'll ask it here.
How would you load in an additional css sheet when a used is logged in.

I want to shave as much overhead for the visitor as possible and this is one of them.
Contains some tweaks so the user menu won't interfere with the admin menu's when logged in.

I've got my main css in style.css and an additional one, named style-admin.css.

Tried looking for something like:

Hello ! I am doing at Drupal 8
So, basically i have a blog page of my site.
And then i want to have the views.

And so i created the views with grid type.
And it's doing just fine.

And then i want to put my banner image of each of every blog into the views. but i fail.
Each of every blog have a banner-image..

I have installed the theme Business and I want to turn on the slideshow function but I need to change the images to my own images.

1). I am assuming that I create my image and then upload it to the File Manager and place it in the correct directory. Is this correct?

2) I need to change the slideshow images, there are 3. How do I know the correct dimensions to make a new slideshow?

Thanks

Hi there,

I don't know why but drupal_set_message doesn't seems to be rendered anymore in my theme and I really don't know why (last week it works and I didn't work on the project).

Do you have an idea where can I check what might be wrong ?

In my custom controller I have something like :

        drupal_set_message('test');

        return array(
            '#type' => 'page',
            'content' => $data->all()
        );

And in my template page I have :

Where are variables such as page, messages and tabs set?

For example, where is the tabs variable from the following syntax (excluding the word "and" and the whitespace before and after it) set (initially)?:
if ($tabs):

and

print render($tabs);

If my question is unclear, in any way, please let me know so that I can make it clearer.

Any input would be GREATLY appreciated!