json_tree.py

import json
from pathlib import Path

from rich.text import Text

from textual.app import App, ComposeResult
from textual.widgets import Footer, Header, Tree
from textual.widgets.tree import TreeNode


class TreeApp(App):

    BINDINGS = [
        ("a", "add", "Add node"),
        ("c", "clear", "Clear"),
        ("t", "toggle_root", "Toggle root"),
    ]

    def compose(self) -> ComposeResult:
        yield Header()
        yield Footer()
        yield Tree("Root")

    @classmethod
    def add_json(cls, node: TreeNode, json_data: object) -> None:
        """Adds JSON data to a node.

        Args:
            node (TreeNode): A Tree node.
            json_data (object): An object decoded from JSON.
        """

        from rich.highlighter import ReprHighlighter

        highlighter = ReprHighlighter()

        def add_node(name: str, node: TreeNode, data: object) -> None:
            """Adds a node to the tree.

            Args:
                name (str): Name of the node.
                node (TreeNode): Parent node.
                data (object): Data associated with the node.
            """
            if isinstance(data, dict):
                node.set_label(Text(f"{{}} {name}"))
                for key, value in data.items():
                    new_node = node.add("")
                    add_node(key, new_node, value)
            elif isinstance(data, list):
                node.set_label(Text(f"[] {name}"))
                for index, value in enumerate(data):
                    new_node = node.add("")
                    add_node(str(index), new_node, value)
            else:
                node.allow_expand = False
                if name:
                    label = Text.assemble(
                        Text.from_markup(f"[b]{name}[/b]="), highlighter(repr(data))
                    )
                else:
                    label = Text(repr(data))
                node.set_label(label)

        add_node("JSON", node, json_data)

    def on_mount(self) -> None:
        """Load some JSON when the app starts."""
        file_path = Path(__file__).parent / "food.json"
        with open(file_path) as data_file:
            self.json_data = json.load(data_file)

    def action_add(self) -> None:
        """Add a node to the tree."""
        tree = self.query_one(Tree)
        json_node = tree.root.add("JSON")
        self.add_json(json_node, self.json_data)
        tree.root.expand()

    def action_clear(self) -> None:
        """Clear the tree (remove all nodes)."""
        tree = self.query_one(Tree)
        tree.clear()

    def action_toggle_root(self) -> None:
        """Toggle the root node."""
        tree = self.query_one(Tree)
        tree.show_root = not tree.show_root


if __name__ == "__main__":
    app = TreeApp()
    app.run()