TeaDrivenDev.AvaloniaLocalization.FSharp

This is a simple F# type provider to help with localizing Avalonia applications that are safe with respect to changes in the resource file.

The type provider reads an .axaml file containing a resource dictionary and provides a type with string properties for each of the string resources contained in the file.

Such a file would look as follows:

<ResourceDictionary xmlns="https://github.com/avaloniaui"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:system="clr-namespace:System;assembly=System.Runtime">
    <system:String x:Key="Loc.WindowTitle">Application Main Window</system:String>
    <system:String x:Key="Loc.ShowingXFiles.Format">Showing {0} files</system:String>
    <system:String x:Key="Log.LoadingComplete">LoadingComplete</system:String>
</ResourceDictionary>

The provided type Localizer has three parameters:

• FileName is the Avalonia XAML file used to determine the available localization string resources. The path must be relative to the code file in which the provided type is instantiated.
• ListStructure determines the type structure in which the resources are presented.
  • ListStructure.Flat presents all of the resources in a single flat list, with all dots removed from the names.
    • In the above example, the localization type would have the properties LocWindowTitle, LocShowingXFilesFormat, and LogLoadingComplete.
  • ListStructure.Grouped groups the resources by the part before the first dot, with all subsequent dots replaced by underscores. This allows for a better logical organization of a non-trivial number of string resources.
    • In the above example, the localization type would have two properties:
      • Loc with sub-properties WindowTitle and ShowingXFiles_Format
      • Log with sub-property LoadingComplete
• ReturnMode determines whether the properties return the resource keys or the actual current resource values.
  • ReturnMode.Keys causes the resource keys to be returned.
  • ReturnMode.Values causes the resource values to be returned.

The recommended parameterization is using ListStructure.Grouped and ReturnMode.Values:

type Loc = Localizer< @"Localization\LocStrings.axaml", ListStructure.Grouped, ReturnMode.Values >

This is used as such:

let message = String.Format(Loc.Loc.ShowingXFiles_Format, numberOfFiles)

When using ReturnMode.Keys, the actual resource values can be retrieved using the following function:

let locString key =
    match Application.Current.TryGetResource(key, null) with
    | true, resource -> resource :?> string
    | false, _ -> failwith "Resource not found"

With ReturnMode.Keys and e.g. ListStructure.Flat, the above usage then becomes:

let message = String.Format(locString Loc.LocShowingXFilesFormat, numberOfFiles)

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Building:

dotnet tool restore
dotnet paket update
dotnet build -c release

dotnet paket pack nuget --version 0.0.1