public Type SelectComponent([NotNull] string componentName)
{
var assemblies = _assemblyProvider.CandidateAssemblies;
var types = assemblies.SelectMany(a => a.DefinedTypes);
var components =
types
.Where(ViewComponentConventions.IsComponent)
.Select(c => new { Name = ViewComponentConventions.GetComponentName(c), Type = c.AsType() });
var matching =
components
.Where(c => string.Equals(c.Name, componentName, StringComparison.OrdinalIgnoreCase))
.ToArray();
if (matching.Length == 0)
{
return(null);
}
else if (matching.Length == 1)
{
return(matching[0].Type);
}
else
{
var typeNames = string.Join(Environment.NewLine, matching.Select(t => t.Type.FullName));
throw new InvalidOperationException(
Resources.FormatViewComponent_AmbiguousTypeMatch(componentName, typeNames));
}
}
public void IsComponent(Type type, bool expected)
{
// Arrange & Act
var result = ViewComponentConventions.IsComponent(type.GetTypeInfo());
// Assert
Assert.Equal(expected, result);
}
/// <summary>
/// Locates and renders a view specified by <see cref="ViewName"/>. If <see cref="ViewName"/> is <c>null</c>,
/// then the view name searched for is<c>"Default"</c>.
/// </summary>
/// <param name="context">The <see cref="ViewComponentContext"/> for the current component execution.</param>
/// <returns>A <see cref="Task"/> which will complete when view rendering is completed.</returns>
public async Task ExecuteAsync([NotNull] ViewComponentContext context)
{
var viewEngine = ViewEngine ?? ResolveViewEngine(context);
var viewData = ViewData ?? context.ViewContext.ViewData;
string qualifiedViewName;
if (ViewName != null && ViewName.Length > 0 && ViewName[0] == '/')
{
// View name that was passed in is already a rooted path, the view engine will handle this.
qualifiedViewName = ViewName;
}
else
{
// This will produce a string like:
//
// Components/Cart/Default
//
// The view engine will combine this with other path info to search paths like:
//
// Views/Shared/Components/Cart/Default.cshtml
// Views/Home/Components/Cart/Default.cshtml
// Areas/Blog/Views/Shared/Components/Cart/Default.cshtml
//
// This supports a controller or area providing an override for component views.
qualifiedViewName = string.Format(
CultureInfo.InvariantCulture,
ViewPathFormat,
ViewComponentConventions.GetComponentName(context.ComponentType),
ViewName ?? "Default");
}
var view = FindView(context.ViewContext, viewEngine, qualifiedViewName);
var childViewContext = new ViewContext(
context.ViewContext,
view,
ViewData ?? context.ViewContext.ViewData,
context.Writer);
using (view as IDisposable)
{
await view.RenderAsync(childViewContext);
}
}
private static ViewComponentCandidate CreateCandidate(TypeInfo typeInfo)
{
var candidate = new ViewComponentCandidate()
{
FullName = ViewComponentConventions.GetComponentFullName(typeInfo),
ShortName = ViewComponentConventions.GetComponentName(typeInfo),
Type = typeInfo.AsType(),
};
Debug.Assert(!string.IsNullOrEmpty(candidate.FullName));
var separatorIndex = candidate.FullName.LastIndexOf(".");
if (separatorIndex >= 0)
{
candidate.ShortName = candidate.FullName.Substring(separatorIndex + 1);
}
else
{
candidate.ShortName = candidate.FullName;
}
return(candidate);
}
protected virtual bool IsViewComponentType([NotNull] TypeInfo typeInfo)
{
return(ViewComponentConventions.IsComponent(typeInfo));
}