Opened 12 months ago

Last modified 10 months ago

#109 new enhancement

SVG Export object

Reported by: Richard Knapp Owned by: Olly Betts
Priority: trivial Milestone:
Component: aven Version: 1.2.41
Keywords: SVG Export Cc:


After exporting a line plot to SVG, I checked the file. It is interesting the format uses the "path" instead of the "polyline". According W3 SVG, "path" is for shapes instead of lines. Used for a line, it still sometimes imports as a zero width shape instead of a line.

More an informational issue unless W3 changes how shapes are handled in an upcoming version.

Change History (3)

comment:1 Changed 10 months ago by Olly Betts

It's been like that since first added nearly 15 years ago in bef66af356424806cb818f7b96839d69ee412ca6. It would be fairly simple to change, but would make exported SVG files a bit larger.

However, looking at the SVG 1.1 spec I'm not sure this is an invalid way to use path - it seems to me that we're drawing "open shapes", and there's actually an example in the spec showing a line drawn using path:

(I don't see how you can draw a line containing curves like that example does without using path.)

Used for a line, it still sometimes imports as a zero width shape instead of a line.

We should be wrapping the centre-line data with a g element which specifies a non-zero stroke-width and that should be inherited by elements within the g that don't override this.

If that's not happening maybe it isn't actually use of path that's the problem. Can you provide an example file and application which fails to import it suitably?

comment:2 Changed 10 months ago by Richard Knapp

That all makes sense. I was having a lot of trouble importing and rotating the SVG from survex into OmniGraffle?. However, this may be an issue with an open ticket in OG and rotating lines. Noticed most with small SVG (one survey trip worth of data) the SVG would break apart. I think I saw this in InkScape? too but I didn't use it long enough to troubleshoot to see what I was doing incorrectly.

With more survey data, the problem seems to have gone away.

I agree that curved lines require a shape element; just though the survey line would be simpler with a poly. If not, not big deal.

Seems the spec started uwing the path, then they added the poly line later.

Thank you for looking into this and, again, thank you for an excellent app; it has saved my but at least once already with the robust data encasuplation.

comment:3 Changed 10 months ago by Olly Betts

OmniGraffle seems to be proprietary. If you can explain how to reproduce with Inkscape I can easily take a look though.

just thought the survey line would be simpler with a poly

It's actually not - for a single leg path vs polyline looks like:

<path d="M11505.840 -9461.200L11509.940 -9445.300"/>
<polyline points="11505.840,-9461.200 11509.940,-9445.300"/>

Also currently we can pack multiple disconnected pieces of survey together into one path:

<path d="M11505.840 -9461.200L11509.940 -9445.300M11502.200 -9071.880L11494.960 -9070.980"/>
<polyline points="11505.840,-9461.200 11509.940,-9445.300"/><polyline points="11502.200,-9071.880 11494.960,-9070.980"/>
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