How override/customize/theme Drupal Views Exposed Filters form with a custom Twig template? Easy! Real working tutorial. Step by step in 5 mins.
In one project I use two independent date fields "Start Time" and "End Time". Both fields are optional, indecencies and don't know about each other. However, if "End Time" is selected, I need to check "Start Time" and display a message, so the first field shouldn't be empty and "End Time" should be greater or equal. This code shows a solution how to implement.
When in front of me there was a task to make the site with specific breadcrumbs for specific pages, I applied a very simple and quick solution without the contrib modules. Just a few simple PHP lines in the custom module.
Working on one project for the KWALL company, we needed to sort the list of TV programs/events by time ignoring the date. We have created a custom views sort plugin for it.
By using layout plugin we can easy to create own layouts for node add/edit forms. In this article a brief instruction on how to create a custom layout for the form.