API Usage

The API mirrors the CLI pipeline: convert SVG strings to a font, write the font file, then generate a Flutter IconData class.

Job API

For directory-based workflows (same I/O as the CLI), use FontJob and runFontJob:

runFontJob(FontJob(
  inputSvgDir: 'assets/svg',
  outputFontFile: 'fonts/my_icons.otf',
  outputClassFile: 'lib/my_icons.dart',
  className: 'MyIcons',
));

Parse a multi-font yaml config:

final config = parseFontifyConfig(await File('fontify_plus.yaml').readAsString());
final jobs = config.resolve(fontFilter: 'icons');
runFontJobs(jobs);

runFontJob / runFontJobs require dart:io. On web, use the low-level pipeline below with in-memory SVG strings.

Low-level pipeline

final result = svgToOtf(
  svgMap: {'arrow_up': await File('arrow_up.svg').readAsString()},
  fontName: 'My Icons',
);

writeToFile('MyIcons.otf', result.font);

final source = generateFlutterClass(
  glyphList: result.glyphList,
  familyName: result.font.familyName,
  className: 'MyIcons',
  fontFileName: 'MyIcons.otf',
);

Write source to a .dart file with dart:io (or your preferred file API).

svgToOtf

Converts a map of SVG strings into an OpenType font.

Parameter	Type	Default	Description
svgMap	Map<String, String>	(required)	Glyph name to SVG source. Keys become glyph identifiers.
outlineStrokes	bool?	true	Convert stroked paths into the filled region the stroke covers.
preview	bool?	true	Store a minified copy of the input SVG on each glyph for dartdoc previews in the generated IconData class.
normalize	bool?	true	Scale each glyph so its longest side fills the em square, then centre it.
useOpenType	bool?	true	Emit CFF (OpenType) outlines. When false, TrueType outlines are generated with cubic-to-quadratic approximation.
fontName	String?	null	PostScript / family name for the generated font.
strokeWidthRange	StrokeWidthRange?	null	Build a variable font whose wght axis is the stroke width (min and max in SVG units). The maximum is the default instance unless defaultStrokeWidth names another width. Omit for a static font. See Variable stroke width.
defaultStrokeWidth	double?	null	The width the axis opens at, instead of the range maximum. Requires strokeWidthRange and must lie strictly inside it; adds a third master.

Returns a SvgToOtfResult containing:

• glyphList — List<GenericGlyph> of parsed glyphs (pass to generateFlutterClass).
• font — OpenTypeFont instance (pass to writeToFile).

generateFlutterClass

Emits Dart source for a class of IconData constants.

Parameter	Type	Default	Description
glyphList	List<GenericGlyph>	(required)	Glyphs from svgToOtf.
className	String?	null	Generated class name (PascalCase recommended).
familyName	String?	null	Font family name used in each IconData.
package	String?	null	Package name when the font is provided through a dependency.
fontFileName	String?	null	Font file name referenced in generated docs.
indent	int?	2	Leading spaces for class members.
strokeWidthRange	StrokeWidthRange?	null	When set, documents the variable wght axis in the class comment.
defaultStrokeWidth	double?	null	When set alongside strokeWidthRange, names the width the axis opens at in that comment. Pass the same value given to svgToOtf. Ignored without a range.
preview	bool?	null	false omits previews, true always emits them, null emits them unless the file would exceed 2 MiB (dropped with a warning).

Returns the class file contents as a String.

writeToFile / readFromFile

writeToFile(String path, OpenTypeFont font) serialises an OpenTypeFont to disk. Use a .otf extension for CFF-based fonts.

readFromFile(String path) reads an OpenType font back from disk. Both require dart:io and are unavailable on web targets.

Paint attributes

Paint attributes other than stroke geometry — fill colour, gradients, opacity — are ignored. A glyph is a single-colour region; colour comes from the surrounding Flutter text style at render time.