mapcss concat() and cond()

[Polyglot]

This works:

text: rcn_ref;

or:

text: tag(rcn_ref);

When the name tag is present, this also works:

text: concat(tag(rcn_ref), " ", tag(name));

Without a name tag, no text is shown, though.

So I tried this:

text: name?rcn_ref:concat(tag(rcn_ref), " ", tag(name));

and this:

text: cond(name,rcn_ref,concat(tag(rcn_ref), " ", tag(name)));

Would it be possible to simply add a blank string in concat() if the tag is not available.

That would be the most intuitive.

cond() doesn't work as I would expect it either.

Polyglot

[Polyglot]

The following works:

  text: concat(tag(rcn_ref),cond(has_tag_key(name), concat(" ", tag(name)),""));

This too:

  text: cond(has_tag_key(name),concat(tag(rcn_ref), " ", tag(name)),tag(rcn_ref));

It would be a lot simpler if empty tags were simply replaced by an empty string though.

Polyglot

[Polyglot]

I found an easier way to solve the problem: using different ::layers to show the different tags instead of trying to concatenate them.

[bastiK]

please keep open

[Polyglot]

Oh, I'm sorry. It wasn't clear to me whether it was appropriate to have reported it, since there was no reaction (except a more or less negative one, questioning whether it was supposed to work the way I expected it to work) and I managed to solve my problem in another way.

cond() is fine though.

[bastiK]

I implemented it this way, but it kind of bothers me too.

[simon04]

In 6737/josm:

fix #8071 - MapCSS: skip null values in concat(), provide join(separator, value1, ..., valueN)