BindingBase IMarkupExtension <BindingBase> .ProvideValue(IServiceProvider serviceProvider)
{
var targetElement = serviceProvider?.GetService <IProvideValueTarget>()?.TargetObject as BindableObject ?? throw new XamlParseException("Missing serviceProvider, or ProvideValueTarget, or TargetObject", serviceProvider?.GetService <IXmlLineInfoProvider>()?.XmlLineInfo ?? new XmlLineInfo());
var targetProperty = serviceProvider?.GetService <IProvideValueTarget>()?.TargetProperty as BindableProperty ?? throw new XamlParseException("Missing serviceProvider, or ProvideValueTarget, or TargetObject", serviceProvider?.GetService <IXmlLineInfoProvider>()?.XmlLineInfo ?? new XmlLineInfo());
var argument = Argument;
if (GetVariable(argument, ArgumentBinding, targetElement))
{
argument = $"{Argument}: ${variableChangedHandler.VariableId}";
}
(var gqlField, var bindingPath) = ParseField(Field, argument);
//When Binding to a bindingcontext, return a GraphQLObject. Same for ListView.ItemSource
if (targetProperty == BindableObject.BindingContextProperty)
{
var gObject = new GraphQLObject {
EndPoint = EndPoint, Field = gqlField
};
if (Extra != null)
{
((IGraphQLObject)gObject).AddQueryField(new GraphQLField(Extra));
}
if (variableChangedHandler != null)
{
((IGraphQLObject)gObject).AddVariable(variableChangedHandler);
}
return(new Binding(".", mode: BindingMode.OneWay, converter: new GraphQLObjectConverter(), converterParameter: gObject));
}
if (TemplatableProperties.TryGetValue(targetProperty, out var itemTemplateProperty))
{
var gObject = new GraphQLObject {
EndPoint = EndPoint, Field = gqlField
};
if (Extra != null)
{
((IGraphQLObject)gObject).AddQueryField(new GraphQLField(Extra));
}
if (variableChangedHandler != null)
{
((IGraphQLObject)gObject).AddVariable(variableChangedHandler);
}
ApplyContextToMockTemplatedElement(targetElement, itemTemplateProperty, gObject);
return(new Binding(".", mode: BindingMode.OneWay, converter: new GraphQLObjectConverter(), converterParameter: gObject));
}
if (Extra != null)
{
gqlField.SubFields = new List <IGraphQLField> {
new GraphQLField(Extra)
}
}
;
(targetElement.BindingContext as IGraphQLObject)?.AddQueryField(gqlField);
if (variableChangedHandler != null)
{
(targetElement.BindingContext as IGraphQLObject)?.AddVariable(variableChangedHandler);
}
targetElement.BindingContextChanged += (o, e) => {
(((BindableObject)o).BindingContext as IGraphQLObject)?.AddQueryField(gqlField);
if (variableChangedHandler != null)
{
(((BindableObject)o).BindingContext as IGraphQLObject)?.AddVariable(variableChangedHandler);
}
};
return(new Binding($"{nameof(IGraphQLObject.Data)}{bindingPath}", BindingMode.OneWay, converter: new GraphQLValueConverter()));
}
object IMarkupExtension.ProvideValue(IServiceProvider serviceProvider) => (this as IMarkupExtension <BindingBase>).ProvideValue(serviceProvider);
void ApplyContextToMockTemplatedElement(BindableObject targetElement, BindableProperty itemTemplateProperty, GraphQLObject gObject)
{
if (targetElement == null)
{
throw new ArgumentNullException(nameof(gObject));
}
if (itemTemplateProperty == null)
{
throw new ArgumentNullException(nameof(itemTemplateProperty));
}
if (gObject == null)
{
throw new ArgumentNullException(nameof(targetElement));
}
var mockElement = (targetElement.GetValue(itemTemplateProperty) as ElementTemplate)?.CreateContent() as BindableObject;
if (mockElement != null)
{
mockElement.BindingContext = gObject;
mockElement.BindingContext = null;
mockElement = null;
}
targetElement.PropertyChanged += (o, e) => {
if (e.PropertyName != itemTemplateProperty.PropertyName)
{
return;
}
mockElement = (targetElement.GetValue(itemTemplateProperty) as ElementTemplate)?.CreateContent() as BindableObject;
if (mockElement != null)
{
mockElement.BindingContext = gObject;
mockElement.BindingContext = null;
mockElement = null;
}
};
}
