private bool TryExecuteCommand(VueBindingDescription binding, string value)
{
PropertyInfo propertyInfo = _dotnetViewModel.GetType().GetProperty(binding.PropertyName);
if ((propertyInfo != null) && (propertyInfo.PropertyType == typeof(ICommand)))
{
ICommand command = propertyInfo.GetValue(_dotnetViewModel, null) as ICommand;
command.Execute(value);
return(true);
}
return(false);
}
/// <summary>
/// Gets a value from a property of the ViewModel.
/// </summary>
/// <param name="binding">The description of the property binding.</param>
/// <param name="propertyValue">Value of the property.</param>
/// <returns>Returns true if the value could be retrieved successfully, otherwise false.</returns>
private bool TryGetFromViewmodel(VueBindingDescription binding, out object propertyValue)
{
PropertyInfo propertyInfo = _dotnetViewModel.GetType().GetProperty(binding.PropertyName);
if ((propertyInfo != null) && (propertyInfo.CanRead))
{
propertyValue = propertyInfo.GetValue(_dotnetViewModel, null);
return(true);
}
propertyValue = null;
return(false);
}
internal bool TryFormatForView(VueBindingDescription binding, object value, out string formattedValue)
{
PropertyInfo propertyInfo = _dotnetViewModel.GetType().GetProperty(binding.PropertyName);
if (propertyInfo != null)
{
Type propertyType = propertyInfo.PropertyType;
if (value == null)
{
formattedValue = "null";
return(true);
}
else if (propertyType == typeof(string))
{
formattedValue = "'" + WebviewUtils.EscapeJavaScriptString(value.ToString()) + "'";
return(true);
}
else if (typeof(IEnumerable <string>).IsAssignableFrom(propertyType))
{
IEnumerable <string> valueList = (IEnumerable <string>)value;
formattedValue = string.Join(
",", valueList.Select(v => "'" + WebviewUtils.EscapeJavaScriptString(v) + "'"));
formattedValue = "[" + formattedValue + "]";
return(true);
}
else if (propertyType == typeof(bool))
{
formattedValue = value.ToString().ToLowerInvariant();
return(true);
}
else if (propertyType == typeof(int))
{
formattedValue = value.ToString();
return(true);
}
else if (propertyType == typeof(SecureString))
{
// HTML doesn't know the concept of a SecureString, so this is the moment we have to switch.
string unprotectedValue = SecureStringExtensions.SecureStringToString((SecureString)value);
formattedValue = "'" + WebviewUtils.EscapeJavaScriptString(unprotectedValue) + "'";
return(true);
}
}
formattedValue = null;
return(false);
}
private bool TrySetToViewmodel(VueBindingDescription binding, string formattedValue)
{
if (string.IsNullOrEmpty(binding?.PropertyName))
{
return(false);
}
if (TryParseFromView(binding, formattedValue, out object value))
{
PropertyInfo propertyInfo = _dotnetViewModel.GetType().GetProperty(binding.PropertyName);
if ((propertyInfo != null) && (propertyInfo.CanWrite))
{
propertyInfo.SetValue(_dotnetViewModel, value);
return(true);
}
}
return(false);
}
/// <summary>
/// Sets a value to the Vue-model in the View.
/// </summary>
/// <param name="binding">The description of the property binding.</param>
/// <param name="value">New value of the property.</param>
/// <returns>Returns true if the value could be set successfully, otherwise false.</returns>
private bool TrySetToView(VueBindingDescription binding, object value)
{
if (TryFormatForView(binding, value, out string formattedValue))
{
try
{
string script = string.Format(
"var newValue = {2}; if ({0}.{1} != newValue) {0}.{1} = newValue;", "vm", binding.PropertyName, formattedValue);
_htmlView.ExecuteJavaScript(script);
return(true);
}
catch (Exception)
{
// This will return false
}
}
return(false);
}
internal bool TryParseFromView(VueBindingDescription binding, string formattedValue, out object value)
{
PropertyInfo propertyInfo = _dotnetViewModel.GetType().GetProperty(binding.PropertyName);
if (propertyInfo != null)
{
try
{
Type propertyType = propertyInfo.PropertyType;
if (string.Equals("null", formattedValue, StringComparison.InvariantCultureIgnoreCase))
{
value = null;
return(true);
}
else if (propertyType == typeof(string))
{
value = formattedValue;
return(true);
}
else if (propertyType == typeof(bool))
{
value = bool.Parse(formattedValue);
return(true);
}
else if (propertyType == typeof(int))
{
value = int.Parse(formattedValue);
return(true);
}
else if (propertyType == typeof(SecureString))
{
value = SecureStringExtensions.StringToSecureString(formattedValue);
return(true);
}
}
catch (Exception)
{
// This will return false
}
}
value = null;
return(false);
}
/// <summary>
/// This method is called when the viewmodel modified a property and raised an
/// INotifyPropertyChanged event.
/// </summary>
/// <param name="sender">Sender of the event.</param>
/// <param name="e">Event arguments.</param>
private void ViewmodelPropertyChangedHandler(object sender, PropertyChangedEventArgs e)
{
if (!IsListening)
{
return;
}
VueBindingDescription binding = _bindingDescriptions.FindByPropertyName(e.PropertyName);
if (binding == null)
{
return;
}
bool isSuppressedEvent = string.Equals(binding.PropertyName, _suppressedViewmodelPropertyChangedEvent);
if (isSuppressedEvent)
{
return;
}
switch (binding.BindingMode)
{
case VueBindingMode.TwoWay:
case VueBindingMode.OneWayToView:
if (TryGetFromViewmodel(binding, out object propertyValue))
{
TrySetToView(binding, propertyValue);
}
break;
case VueBindingMode.OneWayToViewmodel:
break;
case VueBindingMode.Command:
break; // Should never happen
default:
throw new ArgumentOutOfRangeException(nameof(binding.BindingMode));
}
}
/// <summary>
/// This method is called by the JavaScript, triggered by the Vue model.
/// </summary>
/// <param name="sender">The sender of the event.</param>
/// <param name="uri">The navigation uri, which should be filtered for binding commands.</param>
private void NavigatingEventHandler(object sender, string uri)
{
if (!IsListening || !IsVueBindingUri(uri))
{
return;
}
if (uri.Contains("vueLoaded"))
{
ViewLoadedEvent?.Invoke(this, new EventArgs());
return;
}
string queryPart = GetUriQueryPart(uri);
NameValueCollection queryArguments = HttpUtility.ParseQueryString(queryPart);
string propertyName = queryArguments.Get("name");
string value = queryArguments.Get("value");
VueBindingDescription binding = _bindingDescriptions.FindByPropertyName(propertyName);
if (binding != null)
{
switch (binding.BindingMode)
{
case VueBindingMode.TwoWay:
case VueBindingMode.OneWayToViewmodel:
try
{
// We are inside a changed event from the view, so we do not want to
// handle events from the viewmodel to update the view again, because
// this could lead to circles.
_suppressedViewmodelPropertyChangedEvent = binding.PropertyName;
TrySetToViewmodel(binding, value);
}
finally
{
_suppressedViewmodelPropertyChangedEvent = null;
}
break;
case VueBindingMode.Command:
TryExecuteCommand(binding, value);
break;
case VueBindingMode.OneWayToView:
break; // Should never happen
default:
throw new ArgumentOutOfRangeException(nameof(binding.BindingMode));
}
}
else
{
// Collect individually named arguments
var arguments = new KeyValueList <string, string>(StringComparer.InvariantCultureIgnoreCase);
foreach (string item in queryArguments)
{
if (!string.Equals("name", item, StringComparison.InvariantCultureIgnoreCase) &&
!string.Equals("value", item, StringComparison.InvariantCultureIgnoreCase))
{
arguments[item] = queryArguments[item];
}
}
UnhandledViewBindingEvent?.Invoke(this, new VueBindingUnhandledViewBindingEventArgs(propertyName, value, arguments));
}
}
