Drupal 9.x

I'm receiving an error with a path of Drupal\path_alias\AliasManager

Upgrading to Drupal 9, I was running a test to see which blocks and/or modules would fail.  And there were plenty... like this AliasManager error

Working in Twig, I had to add classes to a pre-existing array.  Whilst I've grown used to the patterns in PHP, these cannot be applied in Twig.  Instead I had to merge the new array elements.

Non associative arrays

Working from a base level, I'll begin as if the original array hasn't been set.  The merge filter expects as first argument an array whose content will be merged with the assigned variable:

On a git pull from remote dev environment to a staging environment running off AWS server... I was greeted with the white screen of death.  While it took me a while to resolve the actual issue, my action plan was as follows:

How to resolve:

1. Look in your log files;
2. Add a few lines to your index.php file

Creating URL's in Drupal programmatically:

Internal path

use Drupal\Core\Link;
use Drupal\Core\Url;

$internal_link = Link::fromTextAndUrl(t('Drupal nodes'), Url::fromUri('internal:/node', $options))->toString();

External Url

use Drupal\Core\Link;
use Drupal\Core\Url;

$external_link = Link::fromTextAndUrl(t('Codebales'), Url::fromUri('http://www.codebales.com/'))->toString();

I was trying to create something quite simple.  How to get image file uri from media entity id or rendered entity. 

Or other variations you might have searched:

• How to load existing media programmatically
• How to get image file uri from media entity id
• Call to a member function getFileUri() 
• drupal File::load getFileUri 
• drupal getFileUri

This guide has been compiled as a reference tool on how to access field values for different field types.

The Manage Display admin UI can change how a field’s label and content are displayed. When I want to show how to output just the Manage Display version of the content, I use the word ‘display’. When I’m talking about the more raw version of the content, I use ‘value’.

Have you come across the following Drupal error message:

Mismatched entity and/or field definitions. The following changes were detected in the entity type and field definitions.

Run a database update status check

drush updatedb:status --entity-updates

Response

If your Composer project doesn't have Drush listed as a dependency, you can install Drush from command line as follows:

composer require drush/drush

To check your version of Drush, use

drush --version

Status check

drush status

Will output something similar to

Running Docker in a new process and creating a container.

Go to the directory using the cd command.  In this instance in the sites directory:

cd ~/Sites

Create a new directory, which can be achieved using mkdir

mkdir mydir

If Docker has been installed then the next command will be all that is required

devcontainer

Don't worry this is an issue that many Drupal developers have come across. In particular it raises its head when you add a subdomain.  Your Drupal website is only showing a plain white screen with “The provided host name is not valid for this server" on it. What does it mean and how to fix it.