How can i use a Backbone.Collection as optionValues for a Backgrid.SelectCell? - backbone.js

Question

I have a Backbone.Collection SprachLandList with a model SprachLand.
SprachLand
'use strict'
module.exports = class SprachLand extends Backbone.Model
SprachLandList
"use strict"
SprachLand = require('../models/SprachLand')
module.exports = class SprachLandList extends Backbone.Collection
model: SprachLand
I want to display another collection with Backgrid and this collection has a model with an attribute with an array of ids referencing the SprachLand models.
Now i want to use the SprachlandList collection for the values of a Select2Cell cell in a Backgrid.
Naively i tried
columns = [
{ name: "id", label: "ID", editable: false, cell: "integer" },
{ name: "bez", label: "Bezeichnung", editable: false, cell: "string" },
{ name: "rub.bez", label: "Rubrik", editable: false, cell: "string" },
{ name: "sl", label: "Sprachlandkombinationen", editable: true, cell:
Backgrid.SelectCell.extend({
#sllist is an instance of the SprachLandList
optionValues: sllist
multiple: true
})
}
]
I want the Select widget display the "bez" attribute" and have the "id" attribute as value.
Here is a JSON representation of sllist
"[{"id":1,"bez":"de-DE"},{"id":2,"bez":"fr-FR"},\
{"id":3,"bez":"en-GB"},{"id":4,"bez":"nl-NL"},\
{"id":5,"bez":"it-IT"},{"id":6,"bez":"de-CH"},\
{"id":7,"bez":"fr-CH"},{"id":8,"bez":"it-CH"},\
{"id":9,"bez":"de-AT"}]"
I get an error:
Uncaught TypeError: 'optionValues' must be of type {Array.<Array>|Array.<{name: string, values: Array.<Array>}>}
How can i get an acceptable representation of the SprachLandList collection for optionValues?

Answer 1

After some searching i found Converting Array of Objects into Array of Arrays
After some meddling i have now a possible solution:
columns = [
{ name: "id", label: "ID", editable: false, cell: "integer" },
{ name: "bez", label: "Bezeichnung", editable: false, cell: "string" },
{ name: "sl", label: "Sprachlandkombinationen", editable: true, cell: Backgrid.SelectCell.extend({
optionValues: sllist.map((obj) ->
nobj = obj.attributes
Object.keys(nobj).sort().map (key) ->
nobj[key]
)
formatter:
fromRaw: (rawValue, model) ->
(if _.isArray(rawValue) then rawValue else (if rawValue? then [rawValue] else []))
toRaw: (formattedValue, model) ->
(if not formattedValue? then [] else _.map(formattedValue, (v) ->
parseInt v
))
multiple: true
})
}
]
The formatter is to convert the string values of the select element back to integers after edit.
Is this a correct solution?