Support helpers

These functions are helpers around LanternUI components, not components themselves. They are documented here to make the boundary explicit. Unless a function is marked public below, hosts should use the component API instead of calling the helper directly. Internal helpers have no compatibility promise.

Form

LanternUI.Components.Form.translate_error/1

translate_error({message, options}) :: String.t()
translate_error(message) when is_binary(message) :: String.t()

This host-facing helper interpolates %{key} bindings in a changeset error tuple and returns a message string. It performs only interpolation; hosts that use Gettext can translate messages before passing explicit errors to input/1. The function is public and intended for form integration, but its stability follows the component's current error contract rather than a separate versioned API.

DatePicker

LanternUI.Components.DatePicker.canonical/2

canonical(value, mode) :: String.t() | nil

This is the normalization step used by the date picker implementation. It converts supported Date, Time, NaiveDateTime, and DateTime values to the picker's canonical strings for :date, :datetime, or :time modes, while empty values become nil. It is marked @doc false and is an internal support helper. Hosts should pass value to date_picker/1, date_time_picker/1, or time_picker/1 instead of calling it.

Pagination

LanternUI.Components.Pagination.window/3

window(page, total, sibling_count) :: [pos_integer() | :gap]

This internal helper builds the page-number window used by pagination/1, including :gap markers between non-adjacent pages. It is marked @doc false. Hosts should provide meta and patch_fn to pagination/1; the window algorithm is not a public compatibility surface.

DataTable URL helpers

LanternUI.Components.DataTable.page_path/3

page_path(path, meta, page_params) :: String.t()

Builds the pagination patch path from meta.params, replacing the page and optionally the page size. It is marked @doc false and is used internally by data_table/1 and Pagination.pagination/1. Hosts should own URL construction and pass a base path to the component.

LanternUI.Components.DataTable.sort_path/3

sort_path(path, meta, field) :: String.t()

Builds the sort patch path from the current query parameters, toggling the direction when the requested field is already the only sort field and removing the page parameter. It is marked @doc false and is an internal implementation helper, not a host URL API.

LanternUI.Components.DataTable.sort_direction/2

sort_direction(meta, field) :: String.t()

Returns "ascending", "descending", or "none" for the requested field. This public helper supplies the ARIA sort value for a sortable table header. It is intended for host-owned table markup that follows the same meta shape; the return values are the current component contract.

LanternUI.Components.DataTable.sort_indicator/2

sort_indicator(meta, field) :: String.t()

Returns the current visual arrow or an empty string for a field without the active sort. It is marked @doc false and is used by data_table/1; hosts should use the component's sortable column support rather than call it.

Calendar

LanternUI.Components.Calendar.weeks/2

weeks(month_start, week_start) :: [[Date.t()]]

Builds the six-row calendar grid for the month and requested first weekday. It is marked @doc false and is an internal rendering helper. Hosts should use calendar/1 or the picker components instead of depending on its grid shape.