Nuclex.Support/ReadMe.md

• Status: Stable and mature. Several projects are using this library, and it has received extensive testing on Linux and Windows.

• Platforms: Cross-platform, developed on Linux but also tested and working without any known issues on Windows.

Nuclex.Support

This library aims to be your trusty toolbox of supporting code for problems that come up in any type of project. It consists of carefully chosen and well-designed pieces that aid you in dealing with settings storage, change notifications, stream processing, object cloning and more.

There are unit tests for the whole library, so everything is verifiably working on all platforms tested (Linux, Windows, Raspberry).

Object Cloning

Whether you use the prototye design patten on complex objects or have another reason, sometimes a deep clone of an object tree is needed. This library provides three complete solutions to cloning objects in .NET:

• The SerializationCloner. It uses .NET's BinarySerializer in a way that will serialize your object tree regardless of whether your objects have the Serializable attribute or not. This is the slowest, least efficient object cloner, but it relies on built-in .NET classes only.

• The ReflectionCloner uses .NET's reflection capabilities (that means interrogating an object what fields and properties it has) to create complete clones of an object, including any arrays and referenced objects. This serializer has no setup time and has pretty decent performance.

• The ExpressionTreeCloner uses Linq expression trees to generate tailored cloning code for your classes at runtime. This method of cloning has a setup time (meaning it takes longer the first time it is confronted with a new class), but from the second clone onwards, is much faster than the others.

All three object cloners can create shallow clones (meaning any references to other object will be kept without copying the referenced objects, too) and deep clones meaning any refeferenced objects (and their referenced objects) will be cloned as well. Careful, this means event subscribers, such a forms and unexpected hangers-on will be cloned, too.

Furthermore, all three object cloners can create property-based clones (where only those settings exposed via properties are cloned), which may skip the non-exposed parts of an object, as well as field-based clones which replicate all the data of a class - any private field and hidden state.

class Example {
  public Example(Example child = null) {
    Child = child;
  }
  public Example Child { get; private set; }
}

class Test {
  public static void CloneSomething() {
    var test = new Example(new Example());

    var reflectionCloner = new ReflectionCloner();
    var clone = reflectionCloner.DeepFieldClone(test);

    // Clone is now a complete copy of test, including the child object
  }
}

Settings

Many applications have to store their settings in an external file or, for pure Windows applications, in the registry. This can be tedious and difficult to unit test, too. Nuclex.Support provides an autonomous ini parser (which works cross-platform and does not rely on GetPrivateProfileString).

Furthermore, it uses an interface to provide the same functionality for the Registry and in-memory settings. This lets you switch between storing your settings in the registry, in an .ini file or constructing a settings container in memory to appropriately unit-test your code with mock data.

static readonly string BasicCategoryName = "Basic";
static readonly string HintsCategoryName = "Hints";

void saveSettings(ISettingStore settingsStore) {
  settingsStore.Set(BasicCategoryName, "AskSaveOnQuit", this.askSaveOnQuit);
  settingsStore.Set(BasicCategoryName, "ActivePanel", this.activePanelIndex);
  settingsStore.Set(HintsCategoryName, "ShowNameHint", this.showNameHint);
  // ...
}

void saveSettingsToIni() {
  var iniStore = new ConfigurationFileStore();
  saveSettings(iniStore);

  using(var writer = new StreamWriteR("awesome-app.ini")) {
    iniStore.Save(writer);
    writer.Flush()
  }
}

void saveSettingsToRegistry() {
  using(
    var registryStore = new WindowsRegistryStore(
      RegistryHive.HKCU, "AwesomeApplication"
    )
  ) {
    saveSettings(registryStore);
  }
}

Observable Base Class

.NET provides the INotifyPropertyChanged interface for objects to expose an event that reports when a property of the object has changed. This is used by data binding UI controls and some ORMs to detect when an object has been changed and the UI or database need to be updated.

It is a bit tedious to implement, so here's a base class to make it much more pleasant to use:

class CreateUserViewModel : Observable {

  public string FirstName {
    get { return this.firstName; }
    set {
      if(value != this.firstName) {
        this.firstName = value;
        OnPropertyChanged(nameof(FirstName));
      }
    }
  }

  private string firstName;

}

There's an extension method for the consuming side, too, with proper handling of wildcard change notifications that are often overlooked:

CreateUserViewModel ViewModel { get; set; } 

void onPropertyChanged(object sender, PropertyChangedEventArgs arguments) {
  if(arguments.AreAffecting(nameof(ViewModel.FirstName))) {
    this.firstNameLine.Text = ViewModel.FirstName;
  }
}