feat: Improvements to selectize plugin defaults/updates

Author: cpsievert

shiny/ui/_input_select.py

@@ -251,8 +251,6 @@ def _input_select_impl(
     if options is not None and selectize is False:
         raise Exception("Options can only be set when selectize is `True`.")
 
-    remove_button = _resolve_remove_button(remove_button, multiple)
-
     resolved_id = resolve_id(id)
 
     choices_ = _normalize_choices(choices)
@@ -264,7 +262,8 @@ def _input_select_impl(
     if options is None:
         options = {}
 
-    opts = _update_options(options, remove_button, multiple)
+    plugins = _get_default_plugins(remove_button, multiple, choices_)
+    options = _add_default_plugins(options, plugins)
 
     choices_tags = _render_choices(choices_, selected)
 
@@ -282,10 +281,10 @@ def _input_select_impl(
             (
                 TagList(
                     tags.script(
-                        dumps(opts),
+                        dumps(options),
                         type="application/json",
                         data_for=resolved_id,
-                        data_eval=dumps(extract_js_keys(opts)),
+                        data_eval=dumps(extract_js_keys(options)),
                     ),
                     selectize_deps(),
                 )
@@ -298,34 +297,35 @@ def _input_select_impl(
     )
 
 
-def _resolve_remove_button(remove_button: Optional[bool], multiple: bool) -> bool:
+def _get_default_plugins(
+    remove_button: bool | None,
+    multiple: bool,
+    choices_: _SelectChoices,
+) -> tuple[str, ...]:
+    if remove_button:
+        # remove_button: remove _each_ item when multiple=True
+        # clear_button: clear _all_ items when multiple=True
+        return ("remove_button", "clear_button")
+
     if remove_button is None:
         if multiple:
-            return True
-        else:
-            return False
-    return remove_button
+            return ("remove_button", "clear_button")
+        if "" in choices_:
+            # Only show clear button if there is an empty choice
+            return ("clear_button",)
+
+    return ()
 
 
-def _update_options(
-    options: dict[str, Any], remove_button: bool, multiple: bool
+def _add_default_plugins(
+    options: dict[str, Any], default_plugins: tuple[str, ...]
 ) -> dict[str, Any]:
     opts = copy.deepcopy(options)
-    plugins = opts.get("plugins", [])
-
-    if remove_button:
-        if multiple:
-            to_add = "remove_button"
-        else:
-            to_add = "clear_button"
-
-        if to_add not in plugins:
-            plugins.append(to_add)
-
-    if not plugins:
-        return options
-
-    opts["plugins"] = plugins
+    p: list[str] = opts.get("plugins", [])
+    if not isinstance(p, list):
+        raise TypeError("`options['plugins']` must be a list.")
+    p.extend(default_plugins)
+    opts["plugins"] = p
     return opts
 
 

shiny/ui/_input_update.py

@@ -36,7 +36,12 @@
 from ..types import ActionButtonValue
 from ._input_check_radio import ChoicesArg, _generate_options
 from ._input_date import _as_date_attr
-from ._input_select import SelectChoicesArg, _normalize_choices, _render_choices
+from ._input_select import (
+    SelectChoicesArg,
+    _add_default_plugins,
+    _normalize_choices,
+    _render_choices,
+)
 from ._input_slider import SliderStepArg, SliderValueArg, _as_numeric, _slider_type
 from ._utils import JSEval, _session_on_flush_send_msg, extract_js_keys
 
@@ -719,6 +724,7 @@ def update_selectize(
     label: Optional[TagChild] = None,
     choices: Optional[SelectChoicesArg] = None,
     selected: Optional[str | list[str]] = None,
+    remove_button: Optional[bool] = None,
     options: Optional[dict[str, str | float | JSEval]] = None,
     server: bool = False,
     session: Optional[Session] = None,
@@ -739,8 +745,11 @@ def update_selectize(
         ``<optgroup>`` labels.
     selected
         The values that should be initially selected, if any.
+    remove_button
+        Whether to show a remove button for the select input.
     options
-        Options to send to update, see `input_selectize` for details.
+        Selectize.js options to customize the behavior of the select input.
+        See <https://selectize.dev/docs/usage> for more details.
     server
         Whether to store choices on the server side, and load the select options
         dynamically on searching, instead of writing all choices into the page at once
@@ -760,7 +769,15 @@ def update_selectize(
 
     session = require_active_session(session)
 
+    if remove_button:
+        options = _add_default_plugins(options or {}, ("remove_button", "clear_button"))
+
     if options is not None:
+        if remove_button is None:
+            # clear_button is problematic when multiple=False
+            # and there is no empty choice
+            options = _add_default_plugins(options, ("remove_button",))
+
         cfg = tags.script(
             json.dumps(options),
             type="application/json",

tests/pytest/test_ui.py

@@ -3,7 +3,7 @@
 from htmltools import HTMLDocument, TagList, tags
 
 from shiny import ui
-from shiny.ui._input_select import _update_options
+from shiny.ui._input_select import _add_remove_button
 
 
 def test_panel_title():
@@ -136,56 +136,3 @@ def test_modal_footer():
         }</script>
         </div>"""
     )
-
-
-def test__update_options():
-    # User does not supply options
-    assert _update_options({}, remove_button=False, multiple=True) == {}
-    assert _update_options({}, remove_button=True, multiple=True) == {
-        "plugins": ["remove_button"]
-    }
-    assert _update_options({}, remove_button=True, multiple=False) == {
-        "plugins": ["clear_button"]
-    }
-
-    # User supplies other plugins
-    d1 = {"plugins": ["foo", "bar"]}
-    assert _update_options(d1, remove_button=True, multiple=True) == {
-        "plugins": ["foo", "bar", "remove_button"]
-    }
-    assert _update_options(d1, remove_button=True, multiple=False) == {
-        "plugins": ["foo", "bar", "clear_button"]
-    }
-    assert _update_options(d1, remove_button=False, multiple=False) == {
-        "plugins": ["foo", "bar"]
-    }
-
-    # User supplies non-plugin options
-    d2 = {"other_key": "foo"}
-
-    assert _update_options(d2, remove_button=True, multiple=True) == {
-        "other_key": "foo",
-        "plugins": ["remove_button"],
-    }
-    assert _update_options(d2, remove_button=True, multiple=True) == {
-        "other_key": "foo",
-        "plugins": ["remove_button"],
-    }
-    assert _update_options(d2, remove_button=False, multiple=False) == d2
-
-    # User supplies clear button plugin
-    d3 = {"plugins": ["clear_button"]}
-
-    assert _update_options(d3, remove_button=True, multiple=True) == {
-        "plugins": ["clear_button", "remove_button"]
-    }
-
-    assert _update_options(d3, remove_button=False, multiple=True) == d3
-    assert _update_options(d3, remove_button=True, multiple=False) == d3
-
-    # User supplies both clear and remove button plugins
-    d4 = {"plugins": ["clear_button", "remove_button"]}
-
-    assert _update_options(d4, remove_button=True, multiple=True) == d4
-    assert _update_options(d4, remove_button=True, multiple=False) == d4
-    assert _update_options(d4, remove_button=False, multiple=False) == d4