Improve CJK names with a lang atttribute on multilingual name fields

[mapmeld]

While researching issues with Chinese characters in OSM tiles and Mapnik, I realized that a similar issue exists in iD's multilingual name UI and it could be improved with a small change

Unicode CJK Unified Ideographs represents characters such as 化 with one codepoint. If the language of the element is Traditional Chinese (lang="zh-Hant"), the text renderer will display the same text differently (化). Luckily we already have the language code when we are setting multilingual names name:zh=*, name:ja=, etc.

Possible issues:

• I set the lang tag when loading the object. I didn't know how to make changing the language dropdown update the input's lang attribute without reorganizing the UI code and callbacks. Open to suggestions on how to do this in D3.
• This doesn't change the appearance of the main name= tag since it can have any language(s)

[tyrasd]

Thanks, setting the this is a good idea! It will likely also benefit screen reader output and other accessibility tools.

Regarding the implementation: yes, this should be set dynamically instead of when creating the dom element:

• in d3, elements that have to be created are handled in <selection>.enter()
• (similarly elements which need to be removed are handled in .exit())
• all remaining elements are still in the original selection object
• here, we have entries and entriesEnter
• at some point these two are combined to get the full updated selection: entries = entries.merge(entriesEnter) (line 452)
• you can use this object to set the properties of the existing and newly created dom elements
• as the entries is the selection of the outer <div> elements, you need to select the correct <input> elements inside the divs first: entries.selectAll('input.localized-value')
• using this sub-selection, you should be able to dynamically set the lang attribute

[tyrasd]

This doesn't change the appearance of the main name= tag since it can have any language(s)

Yeah, we could in theory try to guess the language of the name (e.g. by comparing name with any present name:* tags, or some heuristic based on characters in the name and/or the region of the mapped object). But it's also fine to leave this as is (for now).

[mapmeld]

I wasn't sure how to work with entries.selectAll('input.localized-value') but I did find that setting lang in another location, the utilGetSetValue callback, updates the lang attribute when the user changes the language.

[tyrasd]

Thanks again!

Your implementation works because utilGetSetValue is also working on the input elements of the full set of entries (entries.selectAll('input.localized-value')). Sorry, my instructions must have been a bit confusing. 👍

FYI: In 239a373 I've added the remaining lang attributes on the input elements for wikidata descriptions and the wikipedia's native language name.