[Potlatch-dev] Merging of tags

[Richard Fairhurst]

NopMap wrote:
> I blelieve that an editor  should never, ever set invalid values from valid
> values but rather force the user to make a deliberate decision. Is the
> current state only temporary or intentional?

Temporary, really. But I'm very strongly against "forcing". My favoured 
approach (and I'd be interested to hear what others think) is to build 
this into a wider quality-control UI.

Modal dialogue boxes that say "You merged two ways with different tags - 
select the ones you want before you're allowed to continue" are really, 
really evil things. The user, especially the novice, generally thinks 
"what is this s--t?" and clicks whatever button will cause the box to go 
away most quickly. (Did I mention JOSM's conflict dialogue?) So rather 
than obviously invalid data, you get valid - but wrong - data. That's worse.

That's why P1 gives you a noticeable but modeless, floating notification 
(it even makes a noise :) ) if you merge two ways with conflicting tags.

P2 is more of a challenge. We could do exactly the same as P1, but in 
fact, saying "tags conflict, check them" isn't helpful. The user 
probably edited them through the friendly UI and wasn't exposed to the 
raw tags in the first place, so they won't know what to do.

So, instead, what I'd really like to do is give P2 an internal version 
of KeepRight / OSMQA / the JOSM validator / dupe nodes / all that stuff. 
When there's dodgy data (whether created by the user, or already 
present), highlight it, and explain what's wrong. We already have a 
flexible renderer which we could easily use to highlight it; we just 
need some error detection code, and a floating palette (or somesuch) to 
say "The following problems were found with this way/node".

cheers
Richard