Option to not XML-escape text

[meygerjos]

It would be nice if there was an option to not XML-escape text, so that special characters could be used, as in alignedText 0 0 "Jack&Jill had 5−4 pancakes". Currently this renders as <text ...>Jack&amp;amp;Jill had 5&amp;minus;4 pancakes</text>.

I tracked down what happens to the string that is put into alignedText during rendering. Graphics.Rendering.SVG.renderText sends the string (in a Text object) to Graphics.SVG.Core.toElement, part of the svg-builder package, which runs it through Blaze.ByteString.Builder.Html.Utf8.fromHtmlEscapedString, which is the culprit.

I'm not sure what could be done to get around this. For now my workaround is to run the svg output through sed -i "s/\&/\&/g".

[byorgey]

Thanks for the report, and for the good sleuthing work. I agree there ought to be a better solution here. @jeffreyrosenbluth , any thoughts? I could easily imagine adding a configuration option for the SVG backend to turn off XML-escaping. But it might be nicer to control it on the level of individual strings. That is trickier though since I guess we would have to add functions like unescapedText to diagrams-lib, even though this only makes sense for particular backends like SVG.

[jeffreyrosenbluth]

What would be the downside of not escaping the the text as our default?

[meygerjos]

Backwards incompatibility, and different results for different backends.

[byorgey]

ClaudiusMaximus commented in IRC: "Why not use unicode character instead of &charactername; in the strings?"

[byorgey]

I guess that would work for everything except &.

[meygerjos]

I tried that with a minus sign and I get error: lexical error in string/character literal (UTF-8 decoding error) when I try to compile.

[jeffreyrosenbluth]

@meygerjos That's surprising. I looked at the code in Blaze.ByteString.Builder.Html.Utf8.fromHtmlEscapedString and it seems that it should work. Can you show us an offending code snippet?

[meygerjos]

OK, it works if I save the file in utf-8. I was previously saving the file in japanese-shift-jis-2004 because that was what emacs recommended.