CODEWITHSUNDEEP
swift
GED125
GED125

Reputation: 496

Swift 3: Select an Array based on a dictionary

I have a popover view controller that contains a table view with a list of options, similar to a drop down selection list. This table view is populated dynamically, depending on which "select" button the user hits on the parent view controller. I have several Arrays built for the various option sets to populate the TVC. How can I use the fieldIndex dictionary to automatically set the array to be used as the TVC datasource for the popover?

class MyWidget : NSObject {

  var fieldIndex : [Int:String] = [
        0 : "make",
        1 : "model",
        2 : "year"
  ]

  var make = String()
  var model = String()
  var year = String()   
}

var makes = ["Acme", "Contoso", "Tradewinds"]
var models = ["Model1", "Model2", "Model3"]
var years = ["2015", "2016", "2017"]

Parent View Controller

Upvotes: 0

Views: 380

Answers (3)

Sahil
Sahil

Reputation: 9226

You can simply create dictionary of type Int: [String] 

class MyWidget : NSObject { 
// empty fieldData dictionary of type Int: [String]
var fieldData = [Int: [String]]()

}

// add data like this

fieldData[0] = ["Acme", "Contoso", "Tradewinds"]
fieldData[1] = ["Model1", "Model2", "Model3"]
fieldData[2] = ["2015", "2016", "2017"]

// get data like this

let makeArray = fieldData[0]

Upvotes: 1

Mr. Xcoder
Mr. Xcoder

Reputation: 4795

An alternative to using NSObject is to add this logic into a function directly in your code:

func getArray(_ positionInDictionary: Int) -> [String]{
    var fieldData: [Int:[String]] = [0 : ["Choice 01", "Choice 02", "Choice 03"], 1 : ["Choice 11","Choice 12","Choice 13"]]
    if let str = fieldData[positionInDictionary]{
        return str
    }
    else{ return []}
}

Usage:

var dataArray = getArray(1)

Also, this is IMO the simplest and fastest solution, and you can retrieve your dictionary from wherever you want.

Upvotes: 0

Chris Wagner
Chris Wagner

Reputation: 21013

I might approach it this way.

enum Attribute {
    case make, model, year

    var name: String {
        switch self {
        case .make:     return "Make"
        case .model:    return "Model"
        case .year:     return "Year"
        }
    }

    var allAttribtues: [Attribute] {
        return [.make, .model, .year]
    }
}

class AttributeDataSource {
    func options(for attribute: Attribute) -> [String] {
        switch attribute {
        case .make:     return ["Acme", "Contoso", "Tradewinds"]
        case .model:    return ["Model1", "Model2", "Model3"]
        case .year:     return ["2015", "2016", "2017"]
        }
    }
}

let dataSource = AttributeDataSource()

dataSource.options(for: .make)  // -> ["Acme", "Contoso", "Tradewinds"]
dataSource.options(for: .model) // -> ["Model1", "Model2", "Model3"]
dataSource.options(for: .year)  // -> ["2015", "2016", "2017"]

Don't hesitate to make first-class models for your data structures. Most of the time it will make things much more clear.

Upvotes: 0

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