Theme development

Hello,

I've read that to activate twig debugging you have copy development.services.yml to the default directory, rename it to local.services.yml, remove: 

parameters:
  http.response.debug_cacheability_headers: true

and add:

parameters:
  twig.config:
    debug: true
    auto_reload: true
    cache: false

at the end of the file.

is there a function that allows to do something whenever a theme is installed?

for example, I want to generate a content whenever a theme is installed.

I want to show the D8-based blocks in the block.html.twig file with the <aside> html tag only. However, when I entered this special split file, I created a special branch file for each block area (eg region--sagblok.html.twig), block title and content css, html codes. Unfortunately, the block titles did not appear.

print screen: 

http://s541.photobucket.com/user/veli3350/media/Ekran%20Grnts%202018-02-...

Sorry for my English.

I am trying to organise, an array called $nodes, by a field within the nodes called node_order.

$this->query = $this->query->condition($field, 'EXISTS')->sort($field, 'DESC');

But with no luck.

Now I am looking at:

uasort($nodes, ['Drupal\Component\Utility\SortArray', 'field_node_order.value', 'sortByWeightElement']);

Were can I set the Weight for these pages, as all the child pages are created using the same template type, so I need a way to assign weight to each node. 

I have this

In creating a custom theme I lost the edit page link admins see when they login and created this code:

// get node ID...
    function nosurprise_preprocess_html(&$variables) {
    $nid = $variables['result']['node']->nid;
    $node = node_load($nid);
  
  if(node_access('update',$node)){ print '<span style="font-size:12px;">'; print l( t('Edit Page'),'node/'.$node->nid.'/edit' ); print "</span>"; }
    }

How do I render the html produced by this line: