/// <summary>Adds a trigger for a specified property path on this object.</summary>
/// <param name="source">The trigger source object.</param>
/// <param name="path">The path to the trigger's source property or properties. Use a semicolon (;) to separate multiple
/// property paths. The property path has a flexible syntax that supports defining arbitrarily deep trigger properties.
/// See <see cref="BplPropertyPath"/> for details.</param>
/// <param name="handler">The handler to invoke whenever the trigger property or properties change.</param>
/// <remarks>The handler is invoked at least once, during AddTrigger call itself, representing "unset value" to "current value" change.</remarks>
public static void AddTrigger(this BplObject source, string path, BplTriggerHandler handler) {
try {
if (source == null) throw new Exception("Trigger source is missing");
if (handler == null) throw new Exception("Trigger handler is missing");
var trigger = BplBindingTrigger.Create(source, path, handler);
source.Triggers.Add(trigger);
trigger.IsEnabled = true;
} catch (Exception e) {
BplRuntimeException.Throw("Failed to create trigger '{0}'. {1}".Substitute(path, e.Message), e, source);
}
}
/// <summary>Creates a new <see cref="BplTrigger"/> instance.</summary>
protected BplTrigger(BplObject source, string path, BplTriggerHandler handler) {
PathString = path;
var pathStrings = PathString.Split(@"\s*\;\s*");
var pathCollection = new List<BplPropertyPath>();
for (var i = 0; i < pathStrings.Length; i++) {
pathCollection.Add(new BplPropertyPath(pathStrings[i].Trim()));
}
PathCollection = new ReadOnlyCollection<BplPropertyPath>(pathCollection);
if (PathCollection.Count == 0) {
BplRuntimeException.Throw("Path string is empty");
}
Source = source;
TargetMethod = handler.Method;
var targetObject = handler.Target;
if (targetObject != null) {
_targetObject = new WeakReference(targetObject);
_isInstanceHandler = true;
}
}
/// <summary>Removes all triggers with the given handler from this object.</summary>
public static void RemoveTriggers(this BplObject source, BplTriggerHandler handler) {
source.RemoveTriggers(t => t.TargetMethod == handler.Method);
}
/// <summary>Creates a new <see cref="BplBindingTrigger"/> instance.</summary>
public static BplTrigger Create(BplObject source, string path, BplTriggerHandler handler) {
return new BplBindingTrigger(source, path, handler);
}
/// <summary>Creates a new <see cref="BplBindingTrigger"/> instance.</summary>
protected BplBindingTrigger(BplObject source, string path, BplTriggerHandler handler) : base(source, path, handler) {
}
