Extracting coordinates from FeatureCollection to add to Dictionary as values

Question

I am trying to recreate this ui.Select function with data from an imported FeatureCollection.

In the original example the ui.Select function uses a dictionary that looks like this:

var places = {
  MTV: [-122.0849, 37.3887],
  PEK: [116.4056, 39.9097],
  ZRH: [8.536, 47.376]
};

So I would like to recreate with my own FeatureCollection. My attempt at code for creating the dictionary.

function get_coords(f){return f.centroid()}

var urban_areas = ee.Dictionary.fromLists(boroughs.aggregate_array('lad17nm'), 
                                          ee.List(boroughs.map(get_coords)));
print (urban_areas)

My code is here.

Answer 1

I made a 'toy' example to illustrate a possible solution.

var selector = ui.Select({placeholder:'fetching data..'})

var test_dict = ee.Dictionary.fromLists(['one', 'two'], [[0, 0], [1, 1]])

// Async fetch
test_dict.evaluate(function(dict){
  selector.items().reset(Object.keys(dict))
  selector.onChange(function(key){
    // make your process with value
    var value = dict[key]
    print(value)
  })
  selector.setPlaceholder('Select item..')
})

Map.add(selector)

link: https://code.earthengine.google.com/b183e792df540d4b4c9fbcc8b9a57b2b