Does it render?

Posted by sabas88 on 4 June 2014 in English (English)

Last year I did a quick demo application to mock people asking if an object will get rendered on the map, extracting some information from the stylesheet used for the map on (it was during the switch to the Carto version).

Today I reviewed the process of extracting that information and generated semi-automatically a complete list of key-value pairs, which powers now DoesItRender.

Code is here and thanks to Pages, it’s active on

If a tag is in the style, it answers yes ( If not, it gives option ( to display it via overpass-turbo or xapi-viewer.

Comment from jongleur1983 on 4 June 2014 at 12:24

Hi, still a nice tool - but still open issues IMHO… it says it renders the tag name - yes it does, but only for some objects, as the name tag isn’t rendered anywhere any more. natural=coastline in fact is rendered as well, but treated differently and thus not occuring in the stylesheet.

And of course it would be really(!) great to get a list of sample renderings for a tag that DOES render ;) (which of course may be out of scope for you)

Comment from sabas88 on 4 June 2014 at 13:00

Thanks jongleur :-)

I added some phrases in the output which point to Wiki and TagInfo for the user to gather more info… Some tag wiki pages used to have a description of the result, didn’t them?

Comment from Zverik on 4 June 2014 at 13:47

Can you process multiple styles with this? For example, to answer “it doesn’t render with the default OSM style, but try switching to Humanitarian layer”.

Comment from sabas88 on 4 June 2014 at 14:00

Yes, it originally did that with Mapnik vs Carto.. The code in itself it’s extensible, it only needs a json with the handled tags.. (as I didn’t find a way to automatically search tags easily in the sql queries, we could only consider Filter entries for example).

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