RaspberryIO_26/Swan.Lite/Configuration/ConfiguredObject.cs
2019-12-08 19:54:52 +01:00

71 lines
2.5 KiB
C#

using System;
namespace Swan.Configuration {
/// <summary>
/// Base class for objects whose configuration may be locked,
/// thus becoming read-only, at a certain moment in their lifetime.
/// </summary>
public abstract class ConfiguredObject {
private readonly Object _syncRoot = new Object();
private Boolean _configurationLocked;
/// <summary>
/// Gets a value indicating whether s configuration has already been locked
/// and has therefore become read-only.
/// </summary>
/// <value>
/// <see langword="true"/> if the configuration is locked; otherwise, <see langword="false"/>.
/// </value>
/// <seealso cref="EnsureConfigurationNotLocked"/>
protected Boolean ConfigurationLocked {
get {
lock(this._syncRoot) {
return this._configurationLocked;
}
}
}
/// <summary>
/// <para>Locks this instance's configuration, preventing further modifications.</para>
/// </summary>
/// <remarks>
/// <para>Configuration locking must be enforced by derived classes
/// by calling <see cref="EnsureConfigurationNotLocked"/> at the start
/// of methods and property setters that could change the object's
/// configuration.</para>
/// <para>Immediately before locking the configuration, this method calls <see cref="OnBeforeLockConfiguration"/>
/// as a last chance to validate configuration data, and to lock the configuration of contained objects.</para>
/// </remarks>
/// <seealso cref="OnBeforeLockConfiguration"/>
protected void LockConfiguration() {
lock(this._syncRoot) {
if(this._configurationLocked) {
return;
}
this.OnBeforeLockConfiguration();
this._configurationLocked = true;
}
}
/// <summary>
/// Called immediately before locking the configuration.
/// </summary>
/// <seealso cref="LockConfiguration"/>
protected virtual void OnBeforeLockConfiguration() {
}
/// <summary>
/// Checks whether a module's configuration has become read-only
/// and, if so, throws an <see cref="InvalidOperationException"/>.
/// </summary>
/// <exception cref="InvalidOperationException">The configuration is locked.</exception>
/// <seealso cref="ConfigurationLocked"/>
protected void EnsureConfigurationNotLocked() {
if(this.ConfigurationLocked) {
throw new InvalidOperationException($"Configuration of this {this.GetType().Name} instance is locked.");
}
}
}
}