System Tags

This modules provides the bridge between content and code. It allows developers to use specific entities (like the news-overview page) in their module without knowing the ID of that piece of content.

Use cases:


* I don't want to save the node id of the homepage in config, instead I tag a node with "Homepage" and System Tags will take care of the rest.
* I want to show a list of popular news items in the sidebar on the news overview page, so I tag a node with "News overview" and configure the "System Tags"-condition of that list block to use the "News overview"-System Tag.
* The url of an article should start with the alias of the overview page (/articles/my-news-article). This can be done by using the correct token in the Pathauto pattern for articles.

Setup
The setup is rather easy:


* Add a reference field to the 'System Tag'-entity (eg. field_page_system_tag on Node type 'Page');
* Mark a certain entity with a tag via the field you just created;
* Take a look in Drupal\system_tags\Config\SystemPageConfigOverrider::loadOverrides for how to use this module in your code.

Twig support
A Twig function is included: system_tag_url. It allows 3 parameters: the System Tag ID (required), the entity type (default: node) and an array of options that will be passed to the \Drupal\Core\Entity\EntityInterface::toUrl()-function. Eg. <a href="{{- system_tag_url('homepage') -}}">.

Token support
For every entity type which has a reference field to System Tag, a token will be available. The structure will be the following: system_tags:ENTITY_TYPE--TAG_ID. Eg. [system_tags:node--homepage].

Theming support
When you enable the submodule system_tags_theme, all the configured System Tags, set for the current node, will be available as suggestions. This allows a themer to override the node.html.twig-template, based on the System Tag. Eg. node--system-tag--homepage.html.twig.