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`

Declaration	Value	Meaning
`family`	`"sans"`, `"serif"`, `"mono"`, or an embedded family name	typeface family
`size`	number	font size in points
`bold`	boolean	weight
`italic`	boolean	slant
`underline`	boolean	underline decoration
`strikethrough`	boolean	strikethrough decoration
`uppercase`	boolean	draw the text in capitals
`color`	`#rgb` or `#rrggbb`	text colour, hex only
`background`	`#rgb` or `#rrggbb`	background colour, hex only
`align`	`"left"`, `"center"`, `"right"`	horizontal alignment in the cell
`valign`	`"top"`, `"middle"`, `"bottom"`	vertical alignment in a box taller than its content
`format`	a kind, or `{ kind, digits }` / `{ kind, form }`	how a number or date presents
`currency`	ISO 4217 code	the denomination of a `currency` cell
`spaceBefore` / `spaceAfter`	number >= 0	blank space before or after a band item, in points

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.

Declaration	Value	Meaning
`padding<Side>`	number >= 0	inset in points on that side
`border<Side>Width`	number >= 0	stroke width in points, `0` draws nothing
`border<Side>Style`	`"solid"`, `"dashed"`, `"dotted"`	line style of that side
`border<Side>Color`	`#rgb` or `#rrggbb`	stroke colour of that side

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`

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

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

digits is a whole number from 0 to 20. 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`

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

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

Narrowed sets

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

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

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

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

The report default carries family and size only. An image carries no text declarations. A split slot carries no flow spacing, which stays on the split. 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 report declaring a size therefore doesn’t resize a report header, whose band-role default sits above the document’s.

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

`STYLE_NAMES`

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const STYLE_NAMES: readonly string[]
const RUN_STYLE_NAMES: readonly string[]

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.

Style declarations