Stratify topic
Consider the following table of relationships:
| Name | Parent |
|---|---|
| Eve | |
| Cain | Eve |
| Seth | Eve |
| Enos | Seth |
| Noam | Seth |
| Abel | Eve |
| Awan | Eve |
| Enoch | Awan |
| Azura | Eve |
These names are conveniently unique, so we can unambiguously represent the hierarchy as a CSV file:
name,parent
Eve,
Cain,Eve
Seth,Eve
Enos,Seth
Noam,Seth
Abel,Eve
Awan,Eve
Enoch,Awan
Azura,Eve
To parse the CSV using csvParse:
final table = csvParse(text);
This returns an list of {name, parent} maps:
[
{"name": "Eve", "parent": ""},
{"name": "Cain", "parent": "Eve"},
{"name": "Seth", "parent": "Eve"},
{"name": "Enos", "parent": "Seth"},
{"name": "Noam", "parent": "Seth"},
{"name": "Abel", "parent": "Eve"},
{"name": "Awan", "parent": "Eve"},
{"name": "Enoch", "parent": "Awan"},
{"name": "Azura", "parent": "Eve"}
]
To convert to a hierarchy:
final root = (Stratify()
..id = ((d, i, data) => d["name"])
..parentId = ((d, i, data) => d["parent"]))(table);
This hierarchy can now be passed to a hierarchical layout, such as tree, for visualization.
The stratify operator also works with delimited paths as is common in file systems.