/// <summary>
/// Appends metadata object represented by its factory to the composite metadata being composed.
/// </summary>
/// <typeparam name="TBuilder">Builder type.</typeparam>
/// <typeparam name="TMetadata">Metadata object type to append.</typeparam>
/// <param name="builder">Target builder.</param>
/// <param name="factory">Metadata object factory.</param>
/// <returns>Target builder.</returns>
/// <exception cref="T:System.InvalidOperationException">
/// Thrown if metadata with same type has already been appended.
/// </exception>
public static TBuilder AddMetadata <TMetadata, TBuilder>(this TBuilder builder, Func <ICompositeMetadata, TMetadata> factory)
where TMetadata : IMetadata
where TBuilder : ICompositeMetdataBuilder
{
builder.Add(typeof(TMetadata), MetadataDescriptor.Create(factory));
return(builder);
}
public override Maybe <IMetadata> TryGetValueImpl(MetadataDescriptor descriptor)
{
var desc = (MetadataDescriptor <T>)descriptor;
return(desc.Match(
onValue: v => ((IMetadata)v).AsMaybe(),
onFactory: _ => Maybe.Empty
));
}
public override Maybe <IMetadata> TryInitializeImpl(MetadataDescriptor descriptor, IServiceProvider serviceProvider, ICompositeMetadata target)
{
var desc = (MetadataDescriptor <T>)descriptor;
return(desc.Match(
onFactory: factory => ((IMetadata)factory(serviceProvider, target)).AsMaybe(),
onValue: _ => Maybe.Empty
));
}
public abstract Maybe <IMetadata> TryInitializeImpl(MetadataDescriptor descriptor, IServiceProvider serviceProvider, ICompositeMetadata target);
public abstract Maybe <IMetadata> TryGetValueImpl(MetadataDescriptor descriptor);
public static Maybe <IMetadata> TryInitialize(MetadataDescriptor descriptor, IServiceProvider serviceProvider, ICompositeMetadata target) => _cache.GetOrAdd(descriptor.MetadataType, mtype => (BoxedMatcher)Activator.CreateInstance(typeof(Impl <>).MakeGenericType(mtype), true)) .TryInitializeImpl(descriptor, serviceProvider, target);
public static Maybe <IMetadata> TryGetValue(MetadataDescriptor descriptor) => _cache.GetOrAdd(descriptor.MetadataType, mtype => (BoxedMatcher)Activator.CreateInstance(typeof(Impl <>).MakeGenericType(mtype), true)) .TryGetValueImpl(descriptor);
/// <summary>
/// Appends metadata object represented by its factory to the composite metadata being composed overriding any
/// previous assignment of metadata of the specified type.
/// </summary>
/// <typeparam name="TBuilder">Builder type.</typeparam>
/// <typeparam name="TMetadata">Metadata object type to append or update.</typeparam>
/// <param name="builder">Target builder.</param>
/// <param name="factory">Metadata object factory.</param>
/// <returns>Target builder.</returns>
public static TBuilder SetMetadata <TMetadata, TBuilder>(this TBuilder builder, Func <ICompositeMetadata, TMetadata> factory)
where TMetadata : IMetadata
where TBuilder : ICompositeMetdataBuilder
=> builder.AddOrUpdateMetadata(factory, (_, f) => MetadataDescriptor.Create(f));
/// <summary>
/// Appends metadata object to the composite metadata being composed overriding any previous assignment of
/// metadata of the specified type.
/// </summary>
/// <typeparam name="TBuilder">Builder type.</typeparam>
/// <typeparam name="TMetadata">Metadata object type to append or update.</typeparam>
/// <param name="builder">Target builder.</param>
/// <param name="metadata">Metadata object instance.</param>
/// <returns>Target builder.</returns>
public static TBuilder SetMetadata <TMetadata, TBuilder>(this TBuilder builder, TMetadata metadata)
where TMetadata : IMetadata
where TBuilder : ICompositeMetdataBuilder
=> builder.AddOrUpdateMetadata(metadata, (_, md) => MetadataDescriptor.Create(md));
/// <summary>
/// Either appends metadata object represented by its factory to the composite metadata being composed, or
/// updates existing metadata descriptor.
/// </summary>
/// <typeparam name="TBuilder">Builder type.</typeparam>
/// <typeparam name="TMetadata">Metadata object type to append or update.</typeparam>
/// <param name="builder">Target builder.</param>
/// <param name="factory">Metadata object factory.</param>
/// <param name="update">
/// Function that is invoked if metadata descriptor has already been appended for the specified metadata type.
/// </param>
/// <returns>Target builder.</returns>
public static TBuilder AddOrUpdateMetadata <TMetadata, TBuilder>(this TBuilder builder, Func <IServiceProvider, TMetadata> factory, Func <MetadataDescriptor, Func <IServiceProvider, TMetadata>, MetadataDescriptor> update)
where TMetadata : IMetadata
where TBuilder : ICompositeMetdataBuilder
{
builder[typeof(TMetadata)] = builder.TryGetValue(typeof(TMetadata), out var desc) ? update(desc, factory) : MetadataDescriptor.Create(factory);
return(builder);
}
