Tracking and providing insights about consumption of global elements

[jameskoster]

The need for comprehending the consumption of global entities has been reiterated several times:

• Highlighting Instances of a Pattern's Usage: Patterns: Display a list of all instances where a pattern is used #58990
• Identifying Templates Utilizing a Specific Template Part: Show which templates use a given template part #20476
• Navigation Insights: Navigation: Display the templates in which a navigation is used #53170

It's important to devise a solution that caters to these diverse requirements. In this issue let's attempt to do that!

From a user experience standpoint, I think we can distill the needs into two fundamental pieces:

Contextual understanding of entity consumption

While editing a global entity like a navigation menu, a template, or a synced pattern it's helpful to understand the extent of its use so that you can judge the impact of any changes. This aspect aligns with the ongoing effort to combine the Inspector and Details panels (#59689), and is illustrated through the following mockup:

By tracking this information we can build other small UX enhancements such as warning (or not warning) a user before they delete something, based on whether it's actively in use or not.

Entity consumption analysis in Data Views

Users should also have the ability to explore and manage entities based on their consumption. From the Inspector panel shown in the previous mockup, it would be neat if you could click the "15 templates" or "3 pages" links and be taken to a pre-filtered data view that shows the specific consumers.

Another example of how filtering by consumption can be useful would be allowing users to look up patterns or templates that are currently in (or not in) use:

Registering "Usage" as a field would also allow users to see at a glance where their templates are used:

The template hierarchy will need to be negotiated in order to understand exactly which templates are in use. Since deleting one template can situationally bring a previously unused template into immediate use, this may be one of the trickier parts of this work, and potentially needs handling separately.