Consider using twpayne/go-svg for SVG XML generation

[twpayne]

Refs #292 (comment).

Currently tdewolff/canvas's SVG back end uses fmt.Fprintf to generate the SVG XML strings, for example:

https://github.com/tdewolff/canvas/blob/master/renderers/svg/svg.go#L290-L302

This requires great care to ensure that the resulting document is valid.

I've just developed github.com/twpayne/go-svg which allows you to generate SVG XML at a high level, for example:

	svgElement := svg.New().WidthHeight(4, 4, svg.CM).ViewBox(0, 0, 400, 400).AppendChildren(
		svg.Title(svg.CharData("Example triangle01- simple example of a 'path'")),
		svg.Desc(svg.CharData("A path that draws a triangle")),
		svg.Rect().XYWidthHeight(1, 1, 398, 398, svg.Number).Fill("none").Stroke("blue"),
		svg.Path().D(svgpath.New().
			MoveToAbs([]float64{100, 100}).
			LineToAbs([]float64{300, 100}).
			LineToAbs([]float64{200, 300}).
			ClosePath(),
		).Fill("red").Stroke("blue").StrokeWidth(svg.Number(3)),
	)
	if _, err := svgElement.WriteToIndent(os.Stdout, "", "  "); err != nil {
		panic(err)
	}

Note that twpayne/go-svg is NOT a competitor to tdewolff/canvas. twpayne/go-svg is a low-level SVG XML generation library that could be a useful building block for a high level vector graphics library like tdewolff/canvas.

Maybe this is of interest?

[tdewolff]

Hi Tom, that looks like an awesome library you've been working on, nice! That would definitely improve the readability of the SVG renderers and I'll take a look into using it. I'm a bit swamped with other stuff but will pick this up as I have more time on my hands.

On a side note, the issue you reference is not about writing but about reading SVG. I intend to build an extension on my SVG (and HTML, and XML) parsers in github.com/tdewolff/parse, which are only lexers as of now.

[twpayne]

On a side note, the issue you reference is not about writing but about reading SVG.

Oops, I misunderstood that. Thanks for the clarification. Closing this issue then.