Suppose that the information to be displayed comes from two different views that somehow needs to be joined.  In SQL this can be done using a "UNION' but Views does not have such a construct.  But it does not take a lot of code to achieve this in Drupal 8.

Tracking down an error in PHP code often requires knowledge about how the function is being called.  In cases such as this a stack trace is often useful to show the call stack.  PHP has a function debug_backtrace() that I have found useful in displaying the call stack.  But it seems to use a lot of resources.  So I wanted to quantify this and try a new approach that I have been using lately.  I used something in Drupal 8 that I was debugging.  Results will differ greatly depending on the case but the overall trends should be similar.  I used

Integrated Development Environments (IDEs) are nice for debugging problems but with Docker containers they have to be set up to work remotely. Vim may not be as nice an interface but has an advantage of being able to run in the container making it easier to get set up and running quickly. This is especially true for new releases where there is not much information yet on configuration.

Docker has just been released for Mac OS X and it takes a different approach of using containers.  It claims to be faster and quicker to set up then alternatives such as virtual machines.  I will look at using Docker to set up a basic local development environment for a Drupal 8 website on Ubuntu 16.04.  I will be using PHP 7.0 and MariaDB.  This is done for an actual website and some problems are encountered which will demonstrate how to debug and the tools that can be used to solve issues.

Radio Buttons using NSMatrix has been deprecated and information on how to use Radio Buttons without NSMatrix is difficult to find. So this is documentation of a way to use the new Radios Buttons using Xcode 7.2.1 and Swift 2.1.1.

Create a new Xcode project and choose Cocoa Application under OS X Application. Call it Radio Buttons and check Swift. Do not check Use Storyboards, Create Document-Based Application or Use Core Data.

Swift is a new programming language that builds from Objective C.  Since I liked working with Objective C it only seemed natural to spend time learning Swift.  This article uses Xcode 7.2.1 and Swift 2.1.1.

There are a lot of instructions on the web for installing and configuring DKIM but they vary considerably and many have errors. There also can be gotchas and this article details one of them. Ubuntu 14.04 with Postfix 2.11 are used.

For Ubuntu start by installing DKIM

Javascript code in Drupal 7 used drupal_add_js() to attach Javascript code to a webpage.  The Javascript code then used Drupal.settings.basePath to prepend the path to the Drupal installation.  For Drupal installed in the root directory, Drupal.settings.basePath is just the string '/' but if Drupal is installed in a subdirectory then this is necessary for the Javascript code to continue to work.  The php part is

drupal_add_js(drupal_get_path('module', 'mymodule') . '/mymodule.js');

and the Javascript part is

Many of the changes from Drupal 7 to Drupal 8 involve the use of object oriented code. One particular change is to move away from code specific to nodes to writing the code for entities and then overriding or extending it where necessary for nodes. Conceptually, this results in being able to use much of the same code for other entities including custom entities.

For a small number of taxonomy terms, a select box can be used where the choices are explicitly displayed to the user.  But for larger numbers of terms using a select box becomes problematic.  Using a textfield with autocomplete is an obvious option when there are a large number of terms but it can be discarded because it is not robust to variations in spelling.  This post shows how in Drupal 7 a fuzzy autocomplete can be used to increase robustness.