Drupal 8.x

I've in [mytheme].theme file added cache context into a preprocess_node() hook. This is working great.
However I need to add the same context to all elements of the 'page'. (menus, blocks etc). and also make the 'current context' available to twig. Again working fine for nodes.

What is an appropriate hook to achieve this?

Hi guys,
I'm modifying the template views-view-fields.html.twig in a custom theme (in Drupal8).

In this template, I'd like to show an image-field not in its full size but as a thumbnail or in a smaller size.
Is it possible?
How should I change this code?

Thank you very much.

claudio

in Drupal 8, what would be the best (easiest) way to display a table of data
from a fairly complex oracle query running on Oracle 12.
by complex I mean there are a couple of joins and a few where clauses, its not crazy complicated -
but its more than just a simple select statement.

how do I connect to Oracle, pass in the query and then display the query result on my page ?
can I use views ?

thanks
MRC

I just installed Drupal 8 successfully but having issues installing Drush.
I ran the following:
composer require drush/drush:dev-master
Which installed successfully.
Next when running the drush command I get this:
PHP Fatal error: Call to undefined method Drush\Sql\SqlBase::create() in /var/app/current/mysite/docroot/vendor/drush/drush/src/Boot/DrupalBoot.php on line 505

I searched for this issue and couldn't find any with this particular problem.

Thanks!

I have some pages which use Views table to display the content. Would it be possible to hide a displayed field (or fields) when the site is viewed on smaller screens, such as mobile devices? Thanks for your help.