Observable constructor

Implementation

Observable(this.key, dynamic value,
    {this.scope,
    OnChangeCallback? listener,
    this.getter,
    this.setter,
    this.formatter,
    this.lazyEvaluation = false}) {
  if (value is String) {
    // bindings?
    if (this is! BlobObservable) {
      bindings = Binding.getBindings(value, scope: scope);
    }
    if (bindings != null) {
      // replace the "this" and "parent" operators
      value = replaceReferences(this, scope, value);

      // save the signature
      signature = value;
    }

    // eval?
    isEval = isEvalSignature(value);
    if (_isEval == true) {
      value = getEvalSignature(value);
      signature = value;
    }

    // 2-way
    String t = '@{';
    if ((bindings != null) &&
        (bindings!.length == 1) &&
        (value.trim().toLowerCase().startsWith(t)) &&
        (value.trim().toLowerCase().endsWith('}'))) {
      twoway = true;
      value = (value as String).substring(1);
      signature = value;
    }
  }

  // Set the Value
  if (bindings == null) _value = to(value);

  // Perform Evaluation
  if ((isEval) || bindings != null) onObservableChange(null);

  // Add Listener
  if (listener != null) registerListener(listener);

  // Register
  if (scope != null) scope!.register(this);

  // Notify
  notifyListeners();
}