{"record":{"id":"cb01c95303b702d0","repo":"Textualize/textual","slug":"pane-id-must-be-a-non-empty-string-or-a-contentt","errorCode":null,"errorMessage":"'pane_id' must be a non-empty string or a ContentTab with an id.","messagePattern":"'pane_id' must be a non-empty string or a ContentTab with an id\\.","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"src/textual/widgets/_tabbed_content.py","lineNumber":620,"sourceCode":"\n        Returns:\n            The `TabPane` associated with the ID or the given tab.\n\n        Raises:\n            ValueError: Raised if no ID was available.\n        \"\"\"\n        target_id: str | None = None\n        if isinstance(pane_id, ContentTab):\n            target_id = (\n                pane_id.id if pane_id.id is None else ContentTab.sans_prefix(pane_id.id)\n            )\n        else:\n            target_id = pane_id\n        if target_id:\n            pane = self.get_child_by_type(ContentSwitcher).get_child_by_id(target_id)\n            assert isinstance(pane, TabPane)\n            return pane\n        raise ValueError(\n            \"'pane_id' must be a non-empty string or a ContentTab with an id.\"\n        )\n\n    def _on_tabs_tab_disabled(self, event: Tabs.TabDisabled) -> None:\n        \"\"\"Disable the corresponding tab pane.\"\"\"\n        if event.tabs.parent is not self:\n            return\n        event.stop()\n        tab_id = event.tab.id or \"\"\n        try:\n            with self.prevent(TabPane.Disabled):\n                self.get_child_by_type(ContentSwitcher).get_child_by_id(\n                    ContentTab.sans_prefix(tab_id), expect_type=TabPane\n                ).disabled = True\n        except NoMatches:\n            return\n\n    def _on_tab_pane_disabled(self, event: TabPane.Disabled) -> None:","sourceCodeStart":602,"sourceCodeEnd":638,"githubUrl":"https://github.com/Textualize/textual/blob/06dbeef4bb70fb718236aa418ed658ef4667a126/src/textual/widgets/_tabbed_content.py#L602-L638","documentation":"Raised by TabbedContent.get_pane when pane_id is neither a non-empty string nor a ContentTab with a truthy id. get_pane resolves the id against the internal ContentSwitcher, so it cannot proceed without an id.","triggerScenarios":"get_pane('') or get_pane(tab) where tab.id is None; also called internally via active_pane when the active tab has no id.","commonSituations":"Looking up panes by ContentTab objects whose id was never set, or generating ids from user input that can be empty.","solutions":["Always set ids on Tabs/TabPanes so the whole TabbedContent machinery works.","Check `tab.id` before calling get_pane, or pass the pane's string id directly.","Validate user-provided ids are non-empty."],"exampleFix":"# before\ntabbed_content.get_pane(some_tab)  # some_tab.id is None\n# after\nif some_tab.id:\n    pane = tabbed_content.get_pane(some_tab)","handlingStrategy":"validation","validationCode":"pid = pane_id.id if isinstance(pane_id, ContentTab) else pane_id\nif pid:\n    pane = tabbed_content.get_pane(pid)","typeGuard":null,"tryCatchPattern":"try:\n    pane = tabbed_content.get_pane(pane_id)\nexcept ValueError:\n    pane = None","preventionTips":["Give Tabs and TabPanes explicit ids","Check .id truthiness before lookup"],"tags":["tabbed-content","missing-id","textual"],"backgroundTag":"missing-required-id","analyzedSha":"06dbeef4bb70fb718236aa418ed658ef4667a126","analyzedAt":"2026-08-27T02:36:57.214Z","schemaVersion":2},"datasetVersion":"2026-08-27T03:17:27.898Z"}