Hierarchy View

[nileshtrivedi]

For tables that have link to themselves (example: categories/tags, folders, departments/managers/employees), an option for a two-pane hierarchy view would be great to have.

Typically there are two kinds of hierarchies that come up most often:

• A table where each row has a parent_id that refers to another row in the same table. An example is: Reporting structure in a company where each employee has a manager_id (with a few ones on the top being allowed to have no managers)
• A hierarchy of folders (same as above) but each folder is can have many files in it. Each file therefore, has one and only one folder_id. Example: Organizing the tasks in a todo-list into various categories which are themselves hierarchical. Or a hierarchy of teams/departments with many employees being present in one and only one team.

The reason why the latter is relevant is because when rendering a hierarchy of folders, often the files insides each folder need to be listed as well.

There are different possibilities for the user interface for this view:

1. Same as Gallery view but only the top level items shown as cards. The card for item X acts like folders with some UI option to navigate to X so that all children of X are shown as cards and there's some way to navigate back to parent or ancestors. Think of Mac OS's folder view with Path Bar displayed at the bottom:

2. A two-pane view with hierarchy on the left and detail on the right. Similar to File Explorer in Windows:
   

3. A zoomable treemap. Example: