Svgo: Allow to set or override "preserveAspectRatio" attribute

[mahnunchik]

It can be useful for normalizing svg files or for fixing this bug https://stackoverflow.com/questions/26263550/css-svg-background-strange-transparent-line-around

[GreLI]

I'm afraid it has nothing to do with image optimization. It's a task for an editor.

In case like this it's better to use a little overlap like 1px to prevent such edge effects. There is a lot of such issues when page is zoomed in desktop browsers.

[DonGissel]

It's not just for that. preserveAspectRatio can be used to align the SVG content, regardless of how wide the outer canvas is. Let's say I have an SVG with content that's 64x64 pixels, but the outer element (in this case the <svg>-tag containing the <use>-tag) is 100px wide. I can then use preserveAspectRatio to align the SVG content top left, so I can resize the outer element (using CSS) without worring about flow. Right now, the content is centered no matter what I do, and this is not really great for my current use-case.

It's not just an editor-thing, because SVGO strips the tag off the incoming SVG-files, and there's currently no way to add them again (also, addAttributesToSVGElement doesn't seem to let me add values, and even if it did, I'd want to control this on a per-SVG basis instead of adding a blanket-statement, which would be a lot easier in the source file than in the setup for SVGO); nor is there a way to control this with styling from a browser.

So I would say this is a needed feature.

[jfinken]

Turns out, effectively:

viewBox := fmt.Sprintf(`viewBox="%d %d %d %d"`,
    vbMinX, vbMinY, (vbMaxX - vbMinX), (vbMaxY - vbMinY))
aspect := `preserveAspectRatio="none"`
canvas.Start(width, height, viewBox, aspect)