Style declarations

One closed vocabulary, target-neutral. Each render target maps it to its own model. An unknown name is a definition error. Every value may be a literal or an = expression.

StyleDeclarations

Plus the box below.

valign is legal only where a box has height it didn’t ask for, which means table cells and split slots. On a stacked text item, a band image, or the report default it’s a definition error.

BoxDeclarations

Padding and border, per side. <Side> is Top, Right, Bottom or Left.

Border-box, no collapse. A border side is width, style and colour together, or none. An incomplete literal is a definition error, while an incomplete expression result contributes nothing at render.

FormatDeclaration

type FormatKind = 'number' | 'currency' | 'percent' | 'date'
type DateForm = 'short' | 'medium' | 'long' | 'full'

type NegativeReading = 'minus' | 'parens'
type ZeroReading = 'number' | 'dash'

type FormatDeclaration =
  | FormatKind
  | {
      kind: 'number' | 'currency' | 'percent'
      digits?: number
      negative?: NegativeReading
      zero?: ZeroReading
    }
  | { kind: 'date'; form?: DateForm }

digits is a whole number from 0 to 20. negative chooses -1,204.00 or (1,204.00), and zero chooses 0.00 or -. Both default to the first, so no existing definition moves, and date takes neither. A modifier a kind doesn’t understand is a definition error. Only the whole declaration may be an expression, never a modifier inside it.

format and currency are legal wherever a node has a cell value, which means text items, column cells, headers, and total cells. Both are definition errors on an image, on a row’s style, and on the report default. Both are legal on a styled run, which carries the inline half of the vocabulary.

ResolvedFormat

type ResolvedFormat =
  | {
      kind: 'number' | 'currency' | 'percent'
      digits?: number
      negative: NegativeReading
      zero: ZeroReading
    }
  | { kind: 'date'; form: DateForm }

What crosses the event stream. Never the author’s shorthand, always the object with the answer filled in.

Narrowed sets

type ReportStyleDeclarations = Pick<StyleDeclarations, 'family' | 'size'>

type ImageStyleDeclarations = Pick<
  StyleDeclarations,
  'background' | 'align' | 'spaceBefore' | 'spaceAfter' | keyof BoxDeclarations
>

type StackedStyleDeclarations = Omit<StyleDeclarations, 'valign'>

type CellStyleDeclarations = Omit<StyleDeclarations, 'spaceBefore' | 'spaceAfter'>

type RowStyleDeclarations = Omit<
  StyleDeclarations,
  'format' | 'currency' | 'href' | 'spaceBefore' | 'spaceAfter'
>

type SlotStyleDeclarations = Omit<StyleDeclarations, 'spaceBefore' | 'spaceAfter'>

type RunStyleDeclarations = Pick<
  StyleDeclarations,
  | 'family' | 'size' | 'bold' | 'italic' | 'underline' | 'strikethrough'
  | 'color' | 'background' | 'uppercase' | 'format' | 'currency' | 'href'
>

Each set states a narrowing the engine has always applied, so a node’s style type refuses what a render would have refused. The report default carries family and size only, and an image carries no text declarations. A stacked item drops valign: its box is its own height, so there is nothing to align against. A slot’s box is the split’s height, which is why a slot keeps the name. A table cell and a split slot drop flow spacing, which describes a band item rather than a cell. A row box drops that too, and with it the three names that present a value. A box wraps cells and holds none of its own, so format, currency and href have nothing to act on. A styled run carries the inline half. The box and flow spacing describe a block, and align describes a line. Any of them on a run is a definition error naming the run.

Layering

Five layers, outermost in: the target’s own baseline, the report default, then the band-role default a target supplies for headline roles. Then the node’s own style, and last a styled run’s. A split’s style is a node’s own for every slot under it, so it outranks the band-role default. The report header’s band-role size is a factor over the document’s, 1.4×, so a document declaring size: 20 renders its headline at 28.

format layers whole. A cell that names it restates the entire declaration.

STYLE_NAMES

const STYLE_NAMES: readonly string[]
const RUN_STYLE_NAMES: readonly string[]
const REPORT_STYLE_NAMES: readonly string[]
function isBoxName(name: string): boolean

The vocabulary as data, in the order this page lists it. Import it rather than keeping a copy. RUN_STYLE_NAMES is the run’s subset, in the same order, and REPORT_STYLE_NAMES is the report default’s two names. isBoxName answers whether a name is part of the box, a padding or a border side. That’s the partition that defines a table row’s box. A target that removes the box from a style asks it rather than matching the two prefixes itself.