2016-08-02 9 views
8

これは私が今までに書いたウェットテストコードの一部です。しかし、それは面倒です、便利です。すべての繰り返しの理由は、インターフェイスを流暢に保つためです。私は(この場合はViewであることを起こる)基本クラスを増強した場合、それだけでLabel.Textプロパティはによって実装されていないためこのF#コードをどのように乾燥させることができますか? (Fluent Interface)

let label = theme.CreateLabel().WithMargin(new Thickness(5.0)).WithText("Hello") 

のようなものをやってから私を妨げることになる、Viewのインスタンスをバック与えるだろうViewベースクラス。

ここで私の流暢なインターフェイスです。準備する。それは醜い、そして繰り返します。しかし、それも動作し、使用するのが便利です。

私はそれを乾かす明白な方法がありませんでしたか?

module ViewExtensions = 
    let private withTwoWayBinding<'TElement, 'TProperty, 'TViewModel, 'TView when 'TView :> IViewFor<'TViewModel>>(viewModel: 'TViewModel, view: 'TView, viewModelProperty: Expr<'TViewModel -> 'TProperty>, viewProperty: Expr<'TView -> 'TProperty>) (element: 'TElement) = 
     view.Bind(viewModel, ExpressionConversion.toLinq viewModelProperty, ExpressionConversion.toLinq viewProperty) |> ignore 
     element 
    let private withHorizontalOptions<'TElement when 'TElement :> View> options (element: 'TElement) = 
     element.HorizontalOptions <- options 
     element 
    let private withVerticalOptions<'TElement when 'TElement :> View> options (element: 'TElement) = 
     element.VerticalOptions <- options 
     element 
    let private withAlignment<'TElement when 'TElement :> View> horizontalOptions verticalOptions (control: 'TElement) = 
     control |> withHorizontalOptions horizontalOptions |> withVerticalOptions verticalOptions 
    let private withMargin<'TElement when 'TElement :> View> margin (element: 'TElement) = 
     element.Margin <- margin 
     element 
    let private withActions<'TElement> (actions: ('TElement -> unit)[]) (element: 'TElement) = 
     for action in actions do action(element) 
     element 
    type Xamarin.Forms.Entry with 
     member this.WithHorizontalOptions(options) = withHorizontalOptions options this 
     member this.WithVerticalOptions(options) = withHorizontalOptions options this 
     member this.WithAlignment(horizontalOptions, verticalOptions) = withAlignment horizontalOptions verticalOptions this 
     member this.WithTwoWayBinding(viewModel, view, viewModelProperty, viewProperty) = withTwoWayBinding(viewModel, view, viewModelProperty, viewProperty) this 
     member this.WithMargin(margin) = withMargin margin this 
     member this.With(actions) = withActions actions this 
     member this.With(action: Entry -> unit) = this.With([|action|]) 
    type Xamarin.Forms.Grid with 
     member this.WithHorizontalOptions(options) = withHorizontalOptions options this 
     member this.WithVerticalOptions(options) = withHorizontalOptions options this 
     member this.WithAlignment(horizontalOptions, verticalOptions) = withAlignment horizontalOptions verticalOptions this 
     member this.WithMargin(margin) = withMargin margin this 
     member this.With(actions) = withActions actions this 
     member this.With(action: Grid -> unit) = this.With([|action|]) 
    type Xamarin.Forms.StackLayout with 
     member this.WithHorizontalOptions(options) = withHorizontalOptions options this 
     member this.WithVerticalOptions(options) = withHorizontalOptions options this 
     member this.WithAlignment(horizontalOptions, verticalOptions) = withAlignment horizontalOptions verticalOptions this 
     member this.WithMargin(margin) = withMargin margin this 
     member this.With(actions) = withActions actions this 
     member this.With(action: StackLayout -> unit) = this.With([|action|]) 
    type Xamarin.Forms.Button with 
     member this.WithHorizontalOptions(options) = withHorizontalOptions options this 
     member this.WithVerticalOptions(options) = withHorizontalOptions options this 
     member this.WithAlignment(horizontalOptions, verticalOptions) = withAlignment horizontalOptions verticalOptions this 
     member this.WithMargin(margin) = withMargin margin this 
     member this.WithText(text) = this.Text <- text; this 
     member this.With(actions) = withActions actions this 
     member this.With(action: Button -> unit) = this.With([|action|]) 
    type Xamarin.Forms.Switch with 
     member this.WithHorizontalOptions(options) = withHorizontalOptions options this 
     member this.WithVerticalOptions(options) = withHorizontalOptions options this 
     member this.WithAlignment(horizontalOptions, verticalOptions) = withAlignment horizontalOptions verticalOptions this 
     member this.WithTwoWayBinding(viewModel, view, viewModelProperty, viewProperty) = withTwoWayBinding(viewModel, view, viewModelProperty, viewProperty) this 
     member this.WithMargin(margin) = withMargin margin this 
     member this.With(actions) = withActions actions this 
     member this.With(action: Switch -> unit) = this.With([|action|]) 
    type Xamarin.Forms.Label with 
     member this.WithHorizontalOptions(options) = withHorizontalOptions options this 
     member this.WithVerticalOptions(options) = withHorizontalOptions options this 
     member this.WithAlignment(horizontalOptions, verticalOptions) = withAlignment horizontalOptions verticalOptions this 
     member this.WithMargin(margin) = withMargin margin this 
     member this.WithText(text) = this.Text <- text; this 
     member this.With(actions) = withActions actions this 
     member this.With(action: Label -> unit) = this.With([|action|]) 

UPDATE

あなたの助けのおかげので、答えはイエス、私が何かを明らかに行方不明になったています。 TheQuickBrownFoxが説明したように、私は、フォーム

let label = theme.CreateLabel() |> withMargin(new Thickness(5.0)) |> withContent("Hello") 

の何かに流れるようなインターフェイスを変更した場合、その後、あなたは上記を参照モンスターは、このコードの削除は確かに非常に喜ばれる

module ViewExtensions = 
    let withTwoWayBinding<'TElement, 'TProperty, 'TViewModel, 'TView when 'TView :> IViewFor<'TViewModel>>(viewModel: 'TViewModel, view: 'TView, viewModelProperty: Expr<'TViewModel -> 'TProperty>, viewProperty: Expr<'TView -> 'TProperty>) (element: 'TElement) = 
     view.Bind(viewModel, ExpressionConversion.toLinq viewModelProperty, ExpressionConversion.toLinq viewProperty) |> ignore 
     element 
    let withHorizontalOptions options (element: #View) = element.HorizontalOptions <- options; element 
    let withVerticalOptions options (element: #View) = element.VerticalOptions <- options; element 
    let withAlignment horizontalOptions verticalOptions element = element |> withHorizontalOptions horizontalOptions |> withVerticalOptions verticalOptions 
    let withMargin margin (element: #View) = element.Margin <- margin; element 
    let withCaption text (element: #Button) = element.Text <- text; element 
    let withText text (element: #Entry) = element.Text <- text; element 
    let withContent text (element: #Label) = element.Text <- text; element 
    let withSetUpActions<'TElement> (actions: ('TElement -> unit)[]) (element: 'TElement) = (for action in actions do action(element)); element 
    let withSetUpAction<'TElement> (action: 'TElement -> unit) = withSetUpActions([|action|]) 

によって全体を交換することができます。

+2

あなたが行うことはできません拡張メソッドではなく、ポストフィックスアプリケーション(別名「パイプ転送」)ですか?そうすれば、関数を制約付きで汎用にすることができます。 –

+0

私はTheQuickBrownFoxの答えを読むまでは、あなたが何を意味するのかよくわからなかったことを認めなければなりません。今は完璧な意味合いがあります。そしてそれは非常にうまく動作します。更新保留中です。 –

答えて

11

流暢なインターフェースに慣用のF#のアプローチはちょうど前方オペレータ|>

module ViewHelpers 
    let withMargin margin element = ... 
    let withText text element = ... 

open ViewHelpers 

let label = theme.CreateLabel() |> withMargin (new Thickness(5.0)) |> withText "Hello" 

パイプを使用することです、私はあなたにもflexible typesを使用して、関数のシグネチャを短縮することができると思います。

let withMargin margin (element: #View) = ... 
+1

これは素晴らしいですね。私はすぐにそれを試してみると、すべてがうまくいくならばこれを答えとしてマークします。 F#で頻繁に起こるように、私はいつも学んでいます。フレキシブルなタイプはすばらしいアイデアですが、今まで私はこれまで聞いたことがありませんでした。 –

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