use unique ids

[timelyportfolio]

When using mutliple svg from svglite in the browser, the id for clippath and other elements will very likely conflict. Would it be possible to use uuid to prevent this conflict?

[hadley]

Please provide a reproducible example of the problem.

[timelyportfolio]

Sure, if you open this in Chrome (seems to be the most reliable in showing the bug), you will see the clipPath from the first plot is applied to the second, since the DOM requires unique selector id. There is a #cp1 and #cp2 for both plots, and the cp1 and cp2 are applied to the second plot.

library(svglite)
library(htmltools)

browsable(
  tagList(
    htmlSVG({plot(1:10,pch=10)},height=4,width=7),
    htmlSVG({contour(volcano)},height=20,width=20)
  )
)

Deleting the cp2 from the first corrects the problem.

[lionel-]

@timelyportfolio I don't see uuid in the SVG spec. What do you mean?

@hadley generating random ids seems like it would create difficulties regarding reproducibility. I think it would be better to add an argument id_prefix = "" to all device functions, what do you think?

[hadley]

@lionel- alternatively maybe we could use a simple hashing algorithm to ensure that the id is unique? There's only four values, so it shouldn't be too hard

[timelyportfolio]

uuid is not in the SVG spec. Here is the Wiki definition. For reference, here is how it is handled in htmlwidgets ramnathv/htmlwidgets#213.

[lionel-]

@timelyportfolio thanks!

@hadley would using boost::hash() on a std::pair() of std::pair() be a reasonable approach?

[hadley]

Sure, although it might be just as easy to code up something by hand, e.g. paste together the hex representation of each value (maybe coerce to float to make shorter?)

[timelyportfolio]

Unfortunately, this solution does not rectify the situation. Using the same reproducible example as before, I get the same clippaths for each svg. Am I missing something?

example code

library(svglite)
library(htmltools)

browsable(
    tagList(
        htmlSVG({plot(1:10,pch=10)},height=4,width=7),
        htmlSVG({contour(volcano)},height=20,width=20)
    )
)

replicated clippath ids

[lionel-]

yes there was a bug but already fixed, soon to be on master ;)

[timelyportfolio]

Great thanks!