Merge pull request #61 from petereon/prompt_completion

feat: completion callable

beaupy/_beaupy.py

@@ -7,6 +7,7 @@
 
 import math
 import warnings
+from itertools import cycle
 from typing import Any, Callable, List, Optional, Tuple, Type, Union
 
 from rich.console import Console
@@ -128,6 +129,7 @@ def prompt(
     raise_validation_fail: bool = True,
     raise_type_conversion_fail: bool = True,
     initial_value: Optional[str] = None,
+    completion: Optional[Callable[[str], List[str]]] = None,
 ) -> TargetType:
     """Function that prompts the user for written input
 
@@ -155,11 +157,29 @@ def prompt(
         value: List[str] = [*initial_value] if initial_value else []
         cursor_index = len(initial_value) if initial_value else 0
         error: str = ''
+        completion_context = False
+        completion_options: List[str] = []
         while True:
-            rendered = _render_prompt(secure, value, prompt, cursor_index, error)
+            rendered = _render_prompt(secure, value, prompt, cursor_index, error, completion_options)
             error = ''
             _update_rendered(live, rendered)
             keypress = get_key()
+            if keypress in DefaultKeys.tab:
+                if completion:
+                    if not completion_context:
+                        completion_options = completion(''.join(value))
+                        completion_options_iter = cycle(completion_options)
+                        if completion_options:
+                            completion_context = True
+
+                    if completion_context:
+                        value = [*next(completion_options_iter)]
+                        cursor_index = len(value)
+                else:
+                    completion_context = False
+            else:
+                completion_context = False
+
             if keypress in DefaultKeys.interrupt:
                 if Config.raise_on_interrupt:
                     raise KeyboardInterrupt()
@@ -204,8 +224,9 @@ def prompt(
                     raise Abort(keypress)
                 return None
             else:
-                value.insert(cursor_index, str(keypress))
-                cursor_index += 1
+                if not (keypress in DefaultKeys.tab and completion_context):
+                    value.insert(cursor_index, str(keypress))
+                    cursor_index += 1
 
 
 def select(

beaupy/_internals.py

@@ -66,18 +66,26 @@ def _update_rendered(live: Live, renderable: Union[ConsoleRenderable, str]) -> N
     live.refresh()
 
 
-def _render_prompt(secure: bool, typed_values: List[str], prompt: str, cursor_position: int, error: str) -> str:
-    render_value = (len(typed_values) * '*' if secure else ''.join(typed_values)) + ' '
+def _render_prompt(
+    secure: bool, typed_values: List[str], prompt: str, cursor_position: int, error: str, completion_options: List[str] = []
+) -> str:
+    input_value = len(typed_values) * '*' if secure else ''.join(typed_values)
     render_value = (
-        render_value[:cursor_position]
+        (input_value + ' ')[:cursor_position]
         + '[black on white]'  # noqa: W503
-        + render_value[cursor_position]  # noqa: W503
+        + (input_value + ' ')[cursor_position]  # noqa: W503
         + '[/black on white]'  # noqa: W503
-        + render_value[(cursor_position + 1) :]  # noqa: W503,E203
+        + (input_value + ' ')[(cursor_position + 1) :]  # noqa: W503,E203
     )
+
+    if completion_options and not secure:
+        rendered_completion_options = ' '.join(completion_options).replace(input_value, f'[black on white]{input_value}[/black on white]')
+        render_value = f'{render_value}\n{rendered_completion_options}'
+
     render_value = f'{prompt}\n> {render_value}\n\n(Confirm with [bold]enter[/bold])'
     if error:
         render_value = f'{render_value}\n[red]Error:[/red] {error}'
+
     return render_value
 
 

docs/content/examples.md

@@ -133,6 +133,45 @@ very_secret_info = prompt("Type you API key, hehe",
                           secure=True)
 ```
 
+#### Completion
+
+You can provide a python callable such as `Callable[[str], List[str]]` to provide completion options. String passed to the callable is the current user input.
+
+```python
+favorite_color = prompt("What is your favorite color?",
+                        completion=lambda _: ["pink", "PINK", "P1NK"])
+```
+
+A more complex example with path completion:
+
+```python
+from os import listdir
+from pathlib import Path
+
+# ugly hacky path completion callable:
+def path_completion(str_path: str = ""): 
+    if not str_path:
+        return []
+    try:
+        path = Path(str_path)
+        rest = ''
+        if not path.exists():
+            str_path, rest = str_path.rsplit('/', 1)
+            path = Path(str_path or '/')
+
+        filtered_list_dir = [i for i in listdir(path) if i.startswith(rest)]
+
+        if not path.is_absolute():
+            return ['./'+str(Path(path)/i) for i in filtered_list_dir]
+        else:
+            return [str(Path(path)/i) for i in filtered_list_dir]
+    except Exception as e:
+        return []
+
+prompt(">", completion=path_completion)
+```
+
+
 ## Spinners
 
 ### Styling

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = 'beaupy'
-version = '3.5.4'
+version = '3.6.0'
 description = 'A library of elements for interactive TUIs in Python'
 authors = ['Peter Vyboch <[email protected]>']
 license = 'MIT'

test/beaupy_prompt_test.py

@@ -355,3 +355,29 @@ def _(set_raise_on_escape=set_raise_on_escape):
     with raises(Abort) as e:
         prompt(prompt="Try test")
     assert str(e.raised) == "Aborted by user with key (27,)"
+
+@test("Verify that completion works")
+def _():
+    steps = iter([Keys.TAB, Keys.TAB, Keys.ENTER])
+
+    b.get_key = lambda: next(steps)
+    res = prompt(prompt="Try test", completion=lambda _: ["Hello", "World"])
+    assert res == "World"
+
+@test("Verify that completion renders properly")
+def _():
+    steps = iter([Keys.TAB, Keys.TAB, Keys.TAB, Keys.ENTER])
+
+    Live.update = mock.MagicMock()
+    b.get_key = lambda: next(steps)
+    res = prompt(prompt="Try test", completion=lambda _: ["Hello", "World"])
+
+    assert Live.update.call_args_list == [
+        mock.call(renderable='Try test\n> [black on white] [/black on white]\n\n(Confirm with [bold]enter[/bold])'),
+        mock.call(renderable='Try test\n> Hello[black on white] [/black on white]\n[black on white]Hello[/black on white] World\n\n(Confirm with [bold]enter[/bold])'),
+        mock.call(renderable='Try test\n> World[black on white] [/black on white]\nHello [black on white]World[/black on white]\n\n(Confirm with [bold]enter[/bold])'),
+        mock.call(renderable='Try test\n> Hello[black on white] [/black on white]\n[black on white]Hello[/black on white] World\n\n(Confirm with [bold]enter[/bold])'),
+    ]
+
+
+    assert res == "Hello"