The sum of the fields from two features?

[maro-21]

When mapping a church, we usually use amenity=place_of_worship + building=church. But in that case, unfortunately, the iD editor won't display fields related to the building (such as building:levels, roof:shape, etc.), only tags related to amenity=place_of_worship.

What do you think about the editor displaying the combined fields from both presets in such cases?
I'm not just talking about church + building, but other cases as well. I used churches as an example because they very often appear together.

[tordans]

From the top of my head we could try two things if we wanted to

• create a (unsearchable) preset that only matches when both tags are present and that has other fields
• create new files that have unsearchable fields with prerequisiteTag that only show up when needed
• add something to the schema that allows two fields to be merged and one to "win" – not sure if there is a sane way to do that

Writing this down, the prerequisiteTag-building-fields might be something to look into and reuse for all kind of presets that might be a building and something else (postpass could help with finding candidates)

[matkoniecz]

One more option would be iD having special logic to show building preset in such cases, in addition to the main preset

[tyrasd]

iD's presets code is quite strongly tied to there always only being exactly one preset for each feature. This is for UI/UX reasons, but also to keep the code relatively simple. Changing this would require reworking lots of code that touches presets, not just the list of fields in the sidebar (see e.g. the slightly related bug #12071).

From the tagging-schema point of view, it would also be possible to create copies of the building fields that are only shown if the building value is present. E.g. building/levels_building with prerequisiteTags set to building, etc. Those could be either directly added to the respective presets that currently use the building_area/building_area_yes fields. Or alternatively, be collected into a "template" preset and included in the presets that way.

The combination of Building+Amenity/Shop/Office/… seem to be the most prominent case where this would be useful, but there might be more to consider:

• traffic sign + guideposts (example)
• track/path + piste (example)
• hotel + restaurant
• …

[DujaOSM]

Indeed, it would be best to have a "Building" checkbox and/or drop-down as part of many relevant presets. If checked, it would further expand into a section where one could select type, levels, roof and similar.

That would also alleviate the problem expressed in tagging schema #243, where the separate presets for e.g. "Christian Church" and "Church building" confuse mappers and make them populate incomplete data for features.

[maro-21]

• hotel + restaurant

Oh no, combining them together isn't a good practise...

[DujaOSM]

...as described in key:restaurant:

The tag restaurant=* is used to determine whether the facility has a restaurant (such as a hotel). But it's better to map a restaurant as a separate node amenity=restaurant, because such restaurants are usually available also for people who are not customers of the hotel.