SDPAP-7602: Add a URL Redirect editing improvements.

[henrytranvan]

Jira
https://digital-vic.atlassian.net/browse/SDPAP-7602

Issue

The content author adds the site id manually by taxonomy term id.

Change
The content author can select the site from the list.

[christopher-hopper]

@henrytranvan

Would like to see some additions:

1. Change the text URL prefix - https://content-sdp.docker.internal/ - shown before the "Path:" field, when a user chooses a "Site name:" from the drop-down.

See Drupal AJAX forms https://www.drupal.org/docs/drupal-apis/javascript-api/ajax-forms

We want to give the user clearer feedback in the form when they choose a Site from the drop-down. No magic. Let the user know what is happening when a Site is chosen.

2. Set the default "Site name:" to the matching the site-id from "Path:" when editing a URL Redirect.

If I edit an existing URL Redirect, I expect to see the "Site name" chosen already. We can match the "site-id" in the "Path:" and choose the correct "Site name:" as the default value.

3. Some validation to detect (and possibly fix) when someone chooses a "Site name" but has also manually entered a "site-id" prefix in the "Path:" field.

Try to detect and either fix or warn a user when they choose a "Site name" from the drop-down but enter a "site-id" in the "Path:". We don't want the "Path:" being saved like this:

Path: /site-7/site-7/path-to-my-page

or

Path: /site-7/site-12/path-to-my-page

A simple validation should detect and prevent issues when the drop-down for Site name is used but someone has also got a "site-id" written in their redirect "Path" field.

[christopher-hopper]

Just use the Term Id as an integer for the options id.

$options[$term->id()] = $term->getName();

Will allow us to use the integer in validation and possibly AJAX calls to load the term by its id.

[christopher-hopper]

Change none to 0 for the first Site in the drop-down. Use an integer.

Change the Select site to None or - (dash). If a user chooses to not select a site, they're wanting to create a redirect for the CMS. This is allowed. You might want to redirect from a Drupal admin page to another Drupal admin page, so it is okay to not "Select site" but just use the default of no site.

[christopher-hopper]

I think if we're breaking this over multiple lines, it aids readability if you put line breaks between the chained method calls, rather than in the params. I found this a bit hard to read and initially confusing.

I would suggest this is easier to read and follow for me:

    // Get the primary Sites only. Do not load child Sites sections.
    $vocabulary = 'sites';
    $term_tree = \Drupal::entityTypeManager()
      ->getStorage('taxonomy_term')
      ->loadTree($vocabulary, 0, 1, TRUE);

[christopher-hopper]

I'd rename this variable as $vocabulary or $taxonomy for clarity. It's not a "term" so could be a bit confusing or unclear when we read the code. This variable contains the name of the Vocabulary or Taxonomy we want to load from.

Alternatively, don't even store this in a variable at all. If we're not using it more than once, we don't need to use the memory allocation of a variable at all.