A tree is a data type that represents a hierarchical structure with a set of connected nodes, where each node in the tree can be connected to many children, but is connected to exactly one parent, except for the root node, which has no parent. These constraints mean there are no cycles or "loops".


Trees in Arbometa nodes

In Arbometa you can change every node to a tree structure. By default all created nodes have linear structure. It means, that elements in the node are not connected to each other. But in the tree parent-child connections are established between the elements. It allows to create structures with undefined depth.

For example, in the particular examples we can see such connection between punk and post-punk, where punk is a parent and post-punk is its child.

Some preview types are suitable to represent trees and some are not. For example, if you will try to use pie chart preview to represent the tree, parent-child connections will be ignored. If you will use blocks' preview, as we did in the example 1, the connections will be displayed. The child is displayed deeper inside it's parent and with darker background. It's not the only possible solution - it can be redesigned in many different ways.

In the example 2 we used grid preview to display information about music genres, but not about artists.

If you don't understand, what we are talking about, please read about our software development approach.


How we made these examples

1. We've created a node "Music genres" with the only field "Name". How to create a node.
   
2. Marked "Music genres" to be a tree - ticked a checkbox in the detailed view.
   
3. Under the node "Music genres" we've added a child node "Music artists" with one field - name.
4. Added the blocks preview to the music genres.
5. Added the grid preview to the music genres.
6. Automatically generated programming code.
7. Added data to the nodes according to our best knowledge of popular music.
8. Made minor modifications to design.

About information in this example

There are just some music genres and artists mentioned in the example. Not all of them. Not the best ones. Just some. It's all very subjective.


Conclusion

If you have some set of elements (music genres, persons, products or something else) you can handle them like a list (where they are not connected to each other) or like a tree (where they are in a hierarchical structure). In Arbometa all elements in a set have the list structure by default. But you can easily change it to a tree. There are different preview types, that can display tree structure properly - like blocks or grid.


Related topics

How to create a node
About our software development approach
Blocks preview
Grid preview