feat: add search functionality to select and checkbox prompt, based on …

…#42 (#374)

* feat: add search functionality to select and checkbox prompt

This commit is heavily inspired by [gbataille's](https://github.com/gbataille) [PR](#42)

* chore: bump minor version, because of new feature

* chore: bump version in pyproject.toml

* feat: changed prefix filter to search filter, allow all/invert with ctrl

Instead of a prefix filter, the search filter is now searched within all entries. This seems to be more common than a prefix search.

Using the search functionality disabled the ability to select all options or invert the selection in the checkbox control. If the search filter is enabled, these two functionalities can now be used with the key modifier ctrl.

Updated the displayed instructions to match the changes made.

* fix: reverted version bump

---------

Co-authored-by: mario-dg <mario.dagraca@gmx.com>

examples/checkbox_search.py

@@ -0,0 +1,75 @@
+import questionary
+from examples import custom_style_dope
+
+zoo_animals = [
+    "Lion",
+    "Tiger",
+    "Elephant",
+    "Giraffe",
+    "Zebra",
+    "Panda",
+    "Kangaroo",
+    "Gorilla",
+    "Chimpanzee",
+    "Orangutan",
+    "Hippopotamus",
+    "Rhinoceros",
+    "Leopard",
+    "Cheetah",
+    "Polar Bear",
+    "Grizzly Bear",
+    "Penguin",
+    "Flamingo",
+    "Peacock",
+    "Ostrich",
+    "Emu",
+    "Koala",
+    "Sloth",
+    "Armadillo",
+    "Meerkat",
+    "Lemur",
+    "Red Panda",
+    "Wolf",
+    "Fox",
+    "Otter",
+    "Sea Lion",
+    "Walrus",
+    "Seal",
+    "Crocodile",
+    "Alligator",
+    "Python",
+    "Boa Constrictor",
+    "Iguana",
+    "Komodo Dragon",
+    "Tortoise",
+    "Turtle",
+    "Parrot",
+    "Toucan",
+    "Macaw",
+    "Hyena",
+    "Jaguar",
+    "Anteater",
+    "Capybara",
+    "Bison",
+    "Moose",
+]
+
+
+if __name__ == "__main__":
+    toppings = (
+        questionary.checkbox(
+            "Select animals for your zoo",
+            choices=zoo_animals,
+            validate=lambda a: (
+                True if len(a) > 0 else "You must select at least one zoo animal"
+            ),
+            style=custom_style_dope,
+            use_jk_keys=False,
+            use_search_filter=True,
+        ).ask()
+        or []
+    )
+
+    print(
+        f"Alright let's create our zoo with following animals: {', '.join(toppings)}."
+    )

examples/select_search.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+"""Example for a select question type with search enabled.
+
+Run example by typing `python -m examples.select_search` in your console."""
+from pprint import pprint
+
+import questionary
+from examples import custom_style_dope
+from questionary import Choice
+from questionary import Separator
+from questionary import prompt
+
+
+def ask_pystyle(**kwargs):
+    # create the question object
+    question = questionary.select(
+        "What do you want to do?",
+        qmark="😃",
+        choices=[
+            "Order a pizza",
+            "Make a reservation",
+            "Cancel a reservation",
+            "Modify your order",
+            Separator(),
+            "Ask for opening hours",
+            Choice("Contact support", disabled="Unavailable at this time"),
+            "Talk to the receptionist",
+        ],
+        style=custom_style_dope,
+        use_jk_keys=False,
+        use_search_filter=True,
+        **kwargs,
+    )
+
+    # prompt the user for an answer
+    return question.ask()
+
+
+def ask_dictstyle(**kwargs):
+    questions = [
+        {
+            "type": "select",
+            "name": "theme",
+            "message": "What do you want to do?",
+            "choices": [
+                "Order a pizza",
+                "Make a reservation",
+                "Cancel a reservation",
+                "Modify your order",
+                Separator(),
+                "Ask for opening hours",
+                {"name": "Contact support", "disabled": "Unavailable at this time"},
+                "Talk to the receptionist",
+            ],
+        }
+    ]
+
+    return prompt(questions, style=custom_style_dope, **kwargs)
+
+
+if __name__ == "__main__":
+    pprint(ask_pystyle())

questionary/constants.py

@@ -39,6 +39,14 @@
         ("qmark", "fg:#5f819d"),  # token in front of the question
         ("question", "bold"),  # question text
         ("answer", "fg:#FF9D00 bold"),  # submitted answer text behind the question
+        (
+            "search_success",
+            "noinherit fg:#00FF00 bold",
+        ),  # submitted answer text behind the question
+        (
+            "search_none",
+            "noinherit fg:#FF0000 bold",
+        ),  # submitted answer text behind the question
         ("pointer", ""),  # pointer used in select and checkbox prompts
         ("selected", ""),  # style for a selected item of a checkbox
         ("separator", ""),  # separator in lists

questionary/prompts/checkbox.py

@@ -1,3 +1,4 @@
+import string
 from typing import Any
 from typing import Callable
 from typing import Dict
@@ -37,6 +38,7 @@ def checkbox(
     use_arrow_keys: bool = True,
     use_jk_keys: bool = True,
     use_emacs_keys: bool = True,
+    use_search_filter: Union[str, bool, None] = False,
     instruction: Optional[str] = None,
     show_description: bool = True,
     **kwargs: Any,
@@ -105,6 +107,14 @@ def checkbox(
 
         use_emacs_keys: Allow the user to select items from the list using
                         `Ctrl+N` (down) and `Ctrl+P` (up) keys.
+
+        use_search_filter: Flag to enable search filtering. Typing some string will
+                           filter the choices to keep only the ones that contain the
+                           search string.
+                           Note that activating this option disables "vi-like"
+                           navigation as "j" and "k" can be part of a prefix and
+                           therefore cannot be used for navigation
+
         instruction: A message describing how to navigate the menu.
 
         show_description: Display description of current selection if available.
@@ -119,6 +129,11 @@ def checkbox(
             "Emacs keys."
         )
 
+    if use_jk_keys and use_search_filter:
+        raise ValueError(
+            "Cannot use j/k keys with prefix filter search, since j/k can be part of the prefix."
+        )
+
     merged_style = merge_styles_default(
         [
             # Disable the default inverted colours bottom-toolbar behaviour (for
@@ -179,8 +194,9 @@ def get_prompt_tokens() -> List[Tuple[str, str]]:
                         "class:instruction",
                         "(Use arrow keys to move, "
                         "<space> to select, "
-                        "<a> to toggle, "
-                        "<i> to invert)",
+                        f"<{'ctrl-a' if use_search_filter else 'a'}> to toggle, "
+                        f"<{'ctrl-a' if use_search_filter else 'i'}> to invert"
+                        f"{', type to filter' if use_search_filter else ''})",
                     )
                 )
         return tokens
@@ -225,7 +241,7 @@ def toggle(_event):
 
         perform_validation(get_selected_values())
 
-    @bindings.add("i", eager=True)
+    @bindings.add(Keys.ControlI if use_search_filter else "i", eager=True)
     def invert(_event):
         inverted_selection = [
             c.value
@@ -238,7 +254,7 @@ def invert(_event):
 
         perform_validation(get_selected_values())
 
-    @bindings.add("a", eager=True)
+    @bindings.add(Keys.ControlA if use_search_filter else "a", eager=True)
     def all(_event):
         all_selected = True  # all choices have been selected
         for c in ic.choices:
@@ -265,6 +281,17 @@ def move_cursor_up(event):
         while not ic.is_selection_valid():
             ic.select_previous()
 
+    if use_search_filter:
+
+        def search_filter(event):
+            ic.add_search_character(event.key_sequence[0].key)
+
+        for character in string.printable:
+            if character in string.whitespace:
+                continue
+            bindings.add(character, eager=True)(search_filter)
+        bindings.add(Keys.Backspace, eager=True)(search_filter)
+
     if use_arrow_keys:
         bindings.add(Keys.Down, eager=True)(move_cursor_down)
         bindings.add(Keys.Up, eager=True)(move_cursor_up)

questionary/prompts/common.py

@@ -12,11 +12,13 @@
 from prompt_toolkit.filters import Always
 from prompt_toolkit.filters import Condition
 from prompt_toolkit.filters import IsDone
+from prompt_toolkit.keys import Keys
 from prompt_toolkit.layout import ConditionalContainer
 from prompt_toolkit.layout import FormattedTextControl
 from prompt_toolkit.layout import HSplit
 from prompt_toolkit.layout import Layout
 from prompt_toolkit.layout import Window
+from prompt_toolkit.layout.dimension import LayoutDimension
 from prompt_toolkit.styles import Style
 from prompt_toolkit.validation import ValidationError
 from prompt_toolkit.validation import Validator
@@ -236,6 +238,7 @@ class InquirerControl(FormattedTextControl):
     choices: List[Choice]
     default: Optional[Union[str, Choice, Dict[str, Any]]]
     selected_options: List[Any]
+    search_filter: Union[str, None] = None
     use_indicator: bool
     use_shortcuts: bool
     use_arrow_keys: bool
@@ -307,6 +310,7 @@ def __init__(
         self.submission_attempted = False
         self.error_message = None
         self.selected_options = []
+        self.found_in_search = False
 
         self._init_choices(choices, pointed_at)
         self._assign_shortcut_keys()
@@ -375,9 +379,19 @@ def _init_choices(
 
             self.choices.append(choice)
 
+    @property
+    def filtered_choices(self):
+        if not self.search_filter:
+            return self.choices
+        filtered = [
+            c for c in self.choices if self.search_filter.lower() in c.title.lower()
+        ]
+        self.found_in_search = len(filtered) > 0
+        return filtered if self.found_in_search else self.choices
+
     @property
     def choice_count(self) -> int:
-        return len(self.choices)
+        return len(self.filtered_choices)
 
     def _get_choice_tokens(self):
         tokens = []
@@ -457,7 +471,7 @@ def append(index: int, choice: Choice):
             tokens.append(("", "\n"))
 
         # prepare the select choices
-        for i, c in enumerate(self.choices):
+        for i, c in enumerate(self.filtered_choices):
             append(i, c)
 
         current = self.get_pointed_at()
@@ -499,7 +513,7 @@ def select_next(self) -> None:
         self.pointed_at = (self.pointed_at + 1) % self.choice_count
 
     def get_pointed_at(self) -> Choice:
-        return self.choices[self.pointed_at]
+        return self.filtered_choices[self.pointed_at]
 
     def get_selected_values(self) -> List[Choice]:
         # get values not labels
@@ -509,6 +523,39 @@ def get_selected_values(self) -> List[Choice]:
             if (not isinstance(c, Separator) and c.value in self.selected_options)
         ]
 
+    def add_search_character(self, char: Keys) -> None:
+        """Adds a character to the search filter"""
+        if char == Keys.Backspace:
+            self.remove_search_character()
+        else:
+            if self.search_filter is None:
+                self.search_filter = str(char)
+            else:
+                self.search_filter += str(char)
+
+        # Make sure that the selection is in the bounds of the filtered list
+        self.pointed_at = 0
+
+    def remove_search_character(self) -> None:
+        if self.search_filter and len(self.search_filter) > 1:
+            self.search_filter = self.search_filter[:-1]
+        else:
+            self.search_filter = None
+
+    def get_search_string_tokens(self):
+        if self.search_filter is None:
+            return None
+
+        return [
+            ("", "\n"),
+            ("class:question-mark", "/ "),
+            (
+                "class:search_success" if self.found_in_search else "class:search_none",
+                self.search_filter,
+            ),
+            ("class:question-mark", "..."),
+        ]
+
 
 def build_validator(validate: Any) -> Optional[Validator]:
     if validate:
@@ -563,6 +610,10 @@ def create_inquirer_layout(
     )
     _fix_unecessary_blank_lines(ps)
 
+    @Condition
+    def has_search_string():
+        return ic.get_search_string_tokens() is not None
+
     validation_prompt: PromptSession = PromptSession(
         bottom_toolbar=lambda: ic.error_message, **kwargs
     )
@@ -572,6 +623,13 @@ def create_inquirer_layout(
             [
                 ps.layout.container,
                 ConditionalContainer(Window(ic), filter=~IsDone()),
+                ConditionalContainer(
+                    Window(
+                        height=LayoutDimension.exact(2),
+                        content=FormattedTextControl(ic.get_search_string_tokens),
+                    ),
+                    filter=has_search_string & ~IsDone(),
+                ),
                 ConditionalContainer(
                     validation_prompt.layout.container,
                     filter=Condition(lambda: ic.error_message is not None),