create function to get OSM type

[etienneJr]

Context

Following #740 we use Attribute("obj_type","way") in process.lua way_function to include this information in cartes.app tiles. But it is not working well for ways that come from a relation, we have to check the tags, it is not a direct information.

Solution

I wrote this PR to create a function OsmType() which returns the true OSM type of the object, on the same model than the existing Id() function.

Example

Using this in process.lua:

Attribute("OsmId", Id())
Attribute("OsmType", OsmType())

I can directly get tiles with the correct type information

[systemed]

Thanks - this looks good! Sorry for the delay in looking at it. In:

return (isRelation ? "relation " : isWay ? "way " : "node ");

could you remove the trailing spaces?

[etienneJr]

Well, I really don't know why I put those spaces there, but anyway, I've corrected them. Thanks for the review.

I also checked that I could add type in the tiles by using this new OsmType() function (using this lua script), and it worked as expected

Why did the cheks failed ? Do I have to correct something else ?

Thanks !

[systemed]

That's great - thank you!

Don't worry about the tests for now - they're broken and need some attention.