Images are not shown in output

[niknetniko]

When submitting solutions for the Turtle judge, I can't seem to get the images to work:

Tested in both Firefox and Chrome.

(Not entirely sure if this is a turtle judge issue or a Dodona issue, but I'll move the issue to the correct repo if necessary)

[BTWS2]

Thank you for notifying me. Images form submissions that worked correctly in the past are also gone (e.g. https://dodona.ugent.be/nl/submissions/11622640/), but the code from the judge didn't change. This leads me to believe this is a Dodona issue.

[jorg-vr]

Summary of slack discussion:

data:image/svg+xml is no longer supported due to security concerns (see rails/rails-html-sanitizer#147)

I suggest to render svg's inline instead of as an image. This allows for proper sanitizing by rails.

[jorg-vr]

In the code png versions of the images are calculated but never used, so using this might be an option as well if simply inlining the svg does not work. (But inlining the svg still seems prefered as it would also lower complexity of the judge)

judge-turtle/turtle_judge.py

Lines 71 to 94 in 3f3ba3d

	png_submission = generate_png_image(svg_submission, config.canvas_width, config.canvas_height)
	png_solution = generate_png_image(svg_solution, config.canvas_width, config.canvas_height)
	correct_pixels, total_pixels, expected_total = diff_images(png_submission, png_solution)
	base64_submission = base64.b64encode(svg_submission).decode("utf-8")
	base64_solution = base64.b64encode(svg_solution).decode("utf-8")
	html = f"""
	<div style="display:inline-block;width:50%;">
	<p style="padding:10px">{config.translator.translate(Translator.Text.SUBMISSION_TITLE)}</p>
	<img
	alt="submission result"
	style="width:98%;background-color:#fff"
	src="data:image/svg+xml;base64,{base64_submission}" />
	</div>
	<div style="display:inline-block;float:right;width:50%;">
	<p style="padding:10px">{config.translator.translate(Translator.Text.SOLUTION_TITLE)}</p>
	<img
	alt="solution result"
	style="width:98%;background-color:#fff"
	src="data:image/svg+xml;base64,{base64_solution}" />
	</div>
	"""

[BTWS2]

data:image/svg+xml is no longer supported due to security concerns. SVG's are now shown inline. This commit fixed the render: 39bd9cf.

The polyline tag wasn't allowed as a tag. This was fixed by: https://github.com/dodona-edu/dodona/pull/5853.