Use cleaner API and allow custom file in json_tree example

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 - Added `parser_factory` argument to `Markdown` and `MarkdownViewer` constructors https://github.com/Textualize/textual/pull/2075
+- Added the option to supply a custom path in the `json_tree.py` example https://github.com/Textualize/textual/pull/2087
 
 ### Changed
 

examples/json_tree.py

@@ -1,5 +1,7 @@
 import json
+from sys import argv
 from pathlib import Path
+from typing import Optional
 
 from rich.text import Text
 
@@ -16,6 +18,10 @@ class TreeApp(App):
         ("t", "toggle_root", "Toggle root"),
     ]
 
+    def __init__(self, json_path: Optional[Path] = None, *args, **kwargs):
+        self.json_path = json_path or Path(__file__).parent / "food.json"
+        super().__init__(*args, **kwargs)
+
     def compose(self) -> ComposeResult:
         yield Header()
         yield Footer()
@@ -43,31 +49,30 @@ def add_node(name: str, node: TreeNode, data: object) -> None:
                 data (object): Data associated with the node.
             """
             if isinstance(data, dict):
-                node._label = Text(f"{{}} {name}")
+                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._label = Text(f"[] {name}")
+                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
+                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._label = label
+                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:
+        with open(self.json_path) as data_file:
             self.json_data = json.load(data_file)
 
     def action_add(self) -> None:
@@ -89,5 +94,5 @@ def action_toggle_root(self) -> None:
 
 
 if __name__ == "__main__":
-    app = TreeApp()
+    app = TreeApp(json_path=Path(argv[1]) if len(argv) >= 2 else None)
     app.run()