koishi

koishi: render Open Graph (og:image) SVG images from HTML strings and Lustre element trees, using the npm packages @comamoca/komeiji and satori.

Install the npm packages before use (see README):

npm install @comamoca/komeiji satori

Types

</>

A font for satori rendering.

data is the raw font file bytes. satori accepts TTF, OTF, and WOFF (not WOFF2 — use .woff fixtures such as @fontsource’s .woff files).

pub type Font {
  Font(
    name: String,
    data: BitArray,
    weight: Int,
    style: FontStyle,
  )
}

Font(name: String, data: BitArray, weight: Int, style: FontStyle)

</>

pub type FontStyle {
  NormalStyle
  Italic
}

</>

Rendering options. fonts must contain at least one font; satori fails with a SatoriError otherwise.

pub type Options {
  Options(
    width: Int,
    height: Int,
    fonts: List(Font),
    debug: Bool,
  )
}

Options(width: Int, height: Int, fonts: List(Font), debug: Bool)

</>

pub type SatoriError {
  SatoriError(message: String)
}

</>

pub fn to_svg(
  html: String,
  options: Options,
) -> promise.Promise(Result(String, SatoriError))

Render an HTML string to an SVG string.

Internally: @comamoca/komeiji’s html() parses the HTML into a satori-friendly VNode, then satori() renders it to SVG.

koishi.to_svg("<div style=\"color:black;\">hi</div>", options)
// -> Promise(Result(String, SatoriError))