| { |
| "cases": [ |
| { |
| "id": "click-core-help-window", |
| "code": " formatter = ctx.make_formatter()\n self.format_usage(ctx, formatter)\n return formatter.getvalue().rstrip(\"\\n\")\n\n def get_params(self, ctx: Context) -> list[Parameter]:\n params = self.params\n help_option = self.get_help_option(ctx)\n\n if help_option is not None:\n params = [*params, help_option]\n\n if __debug__:\n import warnings\n\n opts = [opt for param in params for opt in param.opts]\n opts_counter = Counter(opts)\n duplicate_opts = (opt for opt, count in opts_counter.items() if count > 1)\n\n for duplicate_opt in duplicate_opts:\n warnings.warn(\n (\n f\"The parameter {duplicate_opt} is used more than once. \"\n \"Remove its duplicate as parameters should be unique.\"\n ),\n stacklevel=3,\n )\n\n return params\n\n def format_usage(self, ctx: Context, formatter: HelpFormatter) -> None:\n \"\"\"Writes the usage line into the formatter.\n\n This is a low-level method called by :meth:`get_usage`.\n \"\"\"\n pieces = self.collect_usage_pieces(ctx)\n formatter.write_usage(ctx.command_path, \" \".join(pieces))\n\n def collect_usage_pieces(self, ctx: Context) -> list[str]:\n \"\"\"Returns all the pieces that go into the usage line and returns\n it as a list of strings.\n \"\"\"\n rv = [self.options_metavar] if self.options_metavar else []\n\n for param in self.get_params(ctx):\n rv.extend(param.get_usage_pieces(ctx))\n\n return rv\n\n def get_help_option_names(self, ctx: Context) -> list[str]:\n \"\"\"Returns the names for the help option.\"\"\"\n all_names = set(ctx.help_option_names)\n for param in self.params:\n all_names.difference_update(param.opts)\n all_names.difference_update(param.secondary_opts)\n return list(all_names)\n\n def get_help_option(self, ctx: Context) -> Option | None:\n \"\"\"Returns the help option object.\n\n Skipped if :attr:`add_help_option` is ``False``.\n\n .. versionchanged:: 8.1.8\n The help option is now cached to avoid creating it multiple times.\n \"\"\"\n help_option_names = self.get_help_option_names(ctx)\n\n if not help_option_names or not self.add_help_option:\n return None\n\n # Cache the help option object in private _help_option attribute to\n # avoid creating it multiple times. Not doing this will break the\n # callback ordering by iter_params_for_processing(), which relies on\n # object comparison.\n if self._help_option is None:\n # Avoid circular import.\n from .decorators import help_option\n\n # Apply help_option decorator and pop resulting option\n help_option(*help_option_names)(self)\n self._help_option = self.params.pop() # type: ignore[assignment]\n\n return self._help_option\n\n def make_parser(self, ctx: Context) -> _OptionParser:\n \"\"\"Creates the underlying option parser for this command.\"\"\"\n parser = _OptionParser(ctx)\n", |
| "query": "Find how Click builds its help option, detects existing option flags, caches the option and returns it. Preserve details needed to diagnose parameter-name collisions." |
| }, |
| { |
| "id": "click-help-decorator", |
| "code": "def help_option(*param_decls: str, **kwargs: t.Any) -> t.Callable[[FC], FC]:\n \"\"\"Pre-configured ``--help`` option which immediately prints the help page\n and exits the program.\n\n :param param_decls: One or more option names. Defaults to the single\n value ``\"--help\"``.\n :param kwargs: Extra arguments are passed to :func:`option`.\n \"\"\"\n\n def show_help(ctx: Context, param: Parameter, value: bool) -> None:\n \"\"\"Callback that print the help page on ``<stdout>`` and exits.\"\"\"\n if value and not ctx.resilient_parsing:\n echo(ctx.get_help(), color=ctx.color)\n ctx.exit()\n\n if not param_decls:\n param_decls = (\"--help\",)\n\n kwargs.setdefault(\"is_flag\", True)\n kwargs.setdefault(\"expose_value\", False)\n kwargs.setdefault(\"is_eager\", True)\n kwargs.setdefault(\"help\", _(\"Show this message and exit.\"))\n kwargs.setdefault(\"callback\", show_help)\n\n return option(*param_decls, **kwargs)\n", |
| "query": "Show how the help option decorator constructs the flag and attaches it to a command." |
| } |
| ], |
| "source_parent": "8c1a0a7abbc1c36f70d1f65f3604acc46c5ce6ab" |
| } |
