NowWebThemeable protocol - iOS

  • Release version: Yokohama
  • Updated January 30, 2025
  • 2 minutes to read
  • The NowWebThemeable protocol provides properties that enable you to override the colors used within web pages hosted on your ServiceNow instance in a native web view.

    public protocol NowWebThemeable {
        var color: NowWebColoring { get }
    }

    The NowWebColoring protocol contains NowUIColoring. This property is used to reference default color variables that NowWebThemeable can use.

    For additional information on how to theme the UI, see Use NowUIColoring to theme NowWebTheme and NowChatTheme in the Mobile SDK Developer Guide - iOS.

    Define WebColors using default colors

    /// Sample structure for using default colors that come with Mobile SDK.
    struct WebColors: NowUIColoring {
    }

    Define WebColors using custom colors

    /// Use custom colors with light theme
    struct WebColors: NowUIColoring {
        private var defaultTheme: NowWebDefaultTheme { NowWebDefaultTheme(nowUITheme: NowUIDefaultTheme())
        }
        
        var brand: UIColor { lightBrand }
        var primary: UIColor { lightPrimary }
        var textPrimary: UIColor { lightTextPrimary }
        var screenHeaderText: UIColor { lightScreenHeaderText }
        var screenHeaderBackground: UIColor { lightScreenHeaderBackground }
        var textActionable: UIColor { lightTextActionable }
        var alertCritical0: UIColor { lightAlertCritical0 }
        var alertCritical3: UIColor { lightAlertCritical3 }
        var alertPositive0: UIColor { lightAlertPositive0 }
        var alertPositive3: UIColor { lightAlertPositive3 }
        var alertLow0: UIColor { lightAlertLow0 }
        var alertWarning0: UIColor { lightAlertWarning0 }
        var backgroundPrimary: UIColor { lightBackgroundPrimary }
        
        // Light Colors
        var lightBrand: UIColor { defaultTheme.color.brand }
        var lightPrimary: UIColor { defaultTheme.color.primary }
        var lightTextPrimary: UIColor { defaultTheme.color.textPrimary }
        var lightScreenHeaderText: UIColor { defaultTheme.color.screenHeaderText }
        var lightScreenHeaderBackground: UIColor { defaultTheme.color.screenHeaderBackground }
        var lightTextActionable: UIColor { defaultTheme.color.textActionble }
        var lightAlertCritical0: UIColor { defaultTheme.color.alertCritical0 }
        var lightAlertCritical3: UIColor { defaultTheme.color.alertCritical3 }
        var lightAlertPositive0: UIColor { defaultTheme.color.alertPositive0 }
        var lightAlertPositive3: UIColor { defaultTheme.color.alertPositive3 }
        var lightAlertLow0: UIColor { defaultTheme.color.alertLow0 }
        var lightAlertWarning0: UIColor { defaultTheme.color.alertWarning0 }
        var lightBackgroundPrimary: UIColor { defaultTheme.color.backgroundPrimary }
    }

    Define WebTheme structure with NowWebThemeable protocol

    struct CarrascoWebTheme: NowWebThemeable {
        var color: NowWebColoring
        
        struct Color: NowWebColoring {
            var nowUIColor: NowUIColoring
        
            var alertPositive0: UIColor
            var alertPositive3: UIColor
            var alertLow0: UIColor
            var alertWarning0: UIColor
            var backgroundPrimary: UIColor
            
            init(inputs: WebColors) {
                nowUIColor = ThemeColor(inputs)
                
                alertPositive0 = inputs.alertPositive0
                alertPositive3 = inputs.alertPositive3
                alertLow0 = inputs.alertLow0
                alertWarning0 = inputs.alertWarning0
                backgroundPrimary = inputs.backgroundPrimary
            }
        }
        
        public init(webColors: WebColors) {
            color = Color(inputs: webColors)
        }
    }
    

    Instantiate a WebTheme object by passing WebColor as input

    let webTheme = CarrascoWebTheme(webColors: WebColors())

    Pass a WebTheme object to NowWebService.makeWebViewController

    func webViewController(for url: URL, delegate: NowWebViewControllerDelegate) -> NowWebViewController? {
      guard let webService = webService else {
        debugPrint("Web service not initialized")
        return nil
      }
      let result = webService.makeWebViewController(for: url, delegate: delegate, theme: CarrascoWebTheme(webColors: WebColors()) )
        
      switch result {
      case .success(let viewController):
        return viewController
      case .failure(let error):
        debugPrint("Web view creation failed with error: \(error.localizedDescription)")
      }
      return nil
    }