Adds an interface for replacing prompt of an individual option in an OptionList

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed relative units not always expanding auto containers https://github.com/Textualize/textual/pull/3059
 - Fixed background refresh https://github.com/Textualize/textual/issues/3055
 
+### Added
+- Added an interface for replacing prompt of an individual option in an `OptionList` https://github.com/Textualize/textual/issues/2603 
 
 ## [0.32.0] - 2023-08-03
 

src/textual/widgets/_option_list.py

@@ -55,6 +55,14 @@ def prompt(self) -> RenderableType:
         """The prompt for the option."""
         return self.__prompt
 
+    def set_prompt(self, prompt: RenderableType) -> None:
+        """Set the prompt for the option.
+
+        Args:
+            prompt: The new prompt for the option.
+        """
+        self.__prompt = prompt
+
     @property
     def id(self) -> str | None:
         """The optional ID for the option."""
@@ -619,12 +627,7 @@ def remove_option(self, option_id: str) -> Self:
         Raises:
             OptionDoesNotExist: If no option has the given ID.
         """
-        try:
-            self._remove_option(self._option_ids[option_id])
-        except KeyError:
-            raise OptionDoesNotExist(
-                f"There is no option with an ID of '{option_id}'"
-            ) from None
+        self._remove_option(self.get_option_index(option_id))
         return self
 
     def remove_option_at_index(self, index: int) -> Self:
@@ -647,6 +650,54 @@ def remove_option_at_index(self, index: int) -> Self:
             ) from None
         return self
 
+    def _replace_option_prompt(self, index: int, prompt: RenderableType) -> None:
+        """Replace the prompt of an option in the list.
+
+        Args:
+            index: The index of the option to replace the prompt of.
+            prompt: The new prompt for the option.
+
+        Raises:
+            OptionDoesNotExist: If there is no option with the given index.
+        """
+        self.get_option_at_index(index).set_prompt(prompt)
+        self._refresh_content_tracking(force=True)
+        self.refresh()
+
+    def replace_option_prompt(self, option_id: str, prompt: RenderableType) -> Self:
+        """Replace the prompt of the option with the given ID.
+
+        Args:
+            option_id: The ID of the option to replace the prompt of.
+            prompt: The new prompt for the option.
+
+        Returns:
+            The `OptionList` instance.
+
+        Raises:
+            OptionDoesNotExist: If no option has the given ID.
+        """
+        self._replace_option_prompt(self.get_option_index(option_id), prompt)
+        return self
+
+    def replace_option_prompt_at_index(
+        self, index: int, prompt: RenderableType
+    ) -> Self:
+        """Replace the prompt of the option at the given index.
+
+        Args:
+            index: The index of the option to replace the prompt of.
+            prompt: The new prompt for the option.
+
+        Returns:
+            The `OptionList` instance.
+
+        Raises:
+            OptionDoesNotExist: If there is no option with the given index.
+        """
+        self._replace_option_prompt(index, prompt)
+        return self
+
     def clear_options(self) -> Self:
         """Clear the content of the option list.
 
@@ -720,12 +771,7 @@ def enable_option(self, option_id: str) -> Self:
         Raises:
             OptionDoesNotExist: If no option has the given ID.
         """
-        try:
-            return self.enable_option_at_index(self._option_ids[option_id])
-        except KeyError:
-            raise OptionDoesNotExist(
-                f"There is no option with an ID of '{option_id}'"
-            ) from None
+        return self.enable_option_at_index(self.get_option_index(option_id))
 
     def disable_option(self, option_id: str) -> Self:
         """Disable the option with the given ID.
@@ -739,12 +785,7 @@ def disable_option(self, option_id: str) -> Self:
         Raises:
             OptionDoesNotExist: If no option has the given ID.
         """
-        try:
-            return self.disable_option_at_index(self._option_ids[option_id])
-        except KeyError:
-            raise OptionDoesNotExist(
-                f"There is no option with an ID of '{option_id}'"
-            ) from None
+        return self.disable_option_at_index(self.get_option_index(option_id))
 
     @property
     def option_count(self) -> int:
@@ -761,7 +802,7 @@ def get_option_at_index(self, index: int) -> Option:
             The option at that index.
 
         Raises:
-            OptionDoesNotExist: If there is no option with the index.
+            OptionDoesNotExist: If there is no option with the given index.
         """
         try:
             return self._options[index]
@@ -779,11 +820,22 @@ def get_option(self, option_id: str) -> Option:
         Returns:
             The option with the ID.
 
+        Raises:
+            OptionDoesNotExist: If no option has the given ID.
+        """
+        return self.get_option_at_index(self.get_option_index(option_id))
+
+    def get_option_index(self, option_id):
+        """Get the index of the option with the given ID.
+
+        Args:
+            option_id: The ID of the option to get the index of.
+
         Raises:
             OptionDoesNotExist: If no option has the given ID.
         """
         try:
-            return self.get_option_at_index(self._option_ids[option_id])
+            return self._option_ids[option_id]
         except KeyError:
             raise OptionDoesNotExist(
                 f"There is no option with an ID of '{option_id}'"

tests/option_list/test_option_prompt_replacement.py

@@ -0,0 +1,72 @@
+"""Test replacing options prompt from an option list."""
+import pytest
+
+from textual.app import App, ComposeResult
+from textual.widgets import OptionList
+from textual.widgets.option_list import Option, OptionDoesNotExist
+
+
+class OptionListApp(App[None]):
+    """Test option list application."""
+
+    def compose(self) -> ComposeResult:
+        yield OptionList(
+            Option("0", id="0"),
+            Option("line1\nline2"),
+        )
+
+
+async def test_replace_option_prompt_with_invalid_id() -> None:
+    """Attempting to replace the prompt of an option ID that doesn't exist should raise an exception."""
+    async with OptionListApp().run_test() as pilot:
+        with pytest.raises(OptionDoesNotExist):
+            pilot.app.query_one(OptionList).replace_option_prompt("does-not-exist", "new-prompt")
+
+
+async def test_replace_option_prompt_with_invalid_index() -> None:
+    """Attempting to replace the prompt of an option index that doesn't exist should raise an exception."""
+    async with OptionListApp().run_test() as pilot:
+        with pytest.raises(OptionDoesNotExist):
+            pilot.app.query_one(OptionList).replace_option_prompt_at_index(23, "new-prompt")
+
+
+async def test_replace_option_prompt_with_valid_id() -> None:
+    """It should be possible to replace the prompt of an option ID that does exist."""
+    async with OptionListApp().run_test() as pilot:
+        option_list = pilot.app.query_one(OptionList)
+        option_list.replace_option_prompt("0", "new-prompt")
+        assert option_list.get_option("0").prompt == "new-prompt"
+
+
+async def test_replace_option_prompt_with_valid_index() -> None:
+    """It should be possible to replace the prompt of an option index that does exist."""
+    async with OptionListApp().run_test() as pilot:
+        option_list = pilot.app.query_one(OptionList).replace_option_prompt_at_index(1, "new-prompt")
+        assert option_list.get_option_at_index(1).prompt == "new-prompt"
+
+
+async def test_replace_single_line_option_prompt_with_multiple() -> None:
+    """It should be possible to replace single line prompt with multiple lines """
+    new_prompt = "new-prompt\nsecond line"
+    async with OptionListApp().run_test() as pilot:
+        option_list = pilot.app.query_one(OptionList)
+        option_list.replace_option_prompt("0", new_prompt)
+        assert option_list.get_option("0").prompt == new_prompt
+
+
+async def test_replace_multiple_line_option_prompt_with_single() -> None:
+    """It should be possible to replace multiple line prompt with a single line"""
+    new_prompt = "new-prompt"
+    async with OptionListApp().run_test() as pilot:
+        option_list = pilot.app.query_one(OptionList)
+        option_list.replace_option_prompt("0", new_prompt)
+        assert option_list.get_option("0").prompt == new_prompt
+
+
+async def test_replace_multiple_line_option_prompt_with_multiple() -> None:
+    """It should be possible to replace multiple line prompt with multiple lines"""
+    new_prompt = "new-prompt\nsecond line"
+    async with OptionListApp().run_test() as pilot:
+        option_list = pilot.app.query_one(OptionList)
+        option_list.replace_option_prompt_at_index(1, new_prompt)
+        assert option_list.get_option_at_index(1).prompt == new_prompt