protected override void BuildRenderTree(Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder builder)
{
// First render out the childcontent to our own RenderTree
var scaffold = new Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder();
//scaffold.OpenComponent<ShallowTest.Shared.OuterComponent>(1);
//scaffold.CloseComponent();
scaffold.AddContent(1, ChildContent);
// Now get the Append method through reflection because they mean and hid it
MethodInfo?AddFrame = builder.GetType().GetMethod("Append", BindingFlags.Instance | BindingFlags.NonPublic);
// This will be used to track skipped frames
int skipTo = 0;
// Check each frame in the RenderTree
foreach (var frame in scaffold.GetFrames().Array)
{
Debug.WriteLine($"Got Frame: {frame.Sequence} : {frame.FrameType} : {skipTo}");
// GetFrames returns at least 16 frames, filled with FrameType None
// but the renderer doesn't like them, so skip them or get errors
if (frame.FrameType != Microsoft.AspNetCore.Components.RenderTree.RenderTreeFrameType.None)
{
// This is how we shallow render - by skipping Component frames
if (frame.FrameType == Microsoft.AspNetCore.Components.RenderTree.RenderTreeFrameType.Component)
{
// Set the next sequence we are going to allow to render
skipTo = frame.Sequence + frame.ComponentSubtreeLength;
// debug - cos you wanna see it happen
Debug.WriteLine($"Skipping Component with length: {frame.ComponentSubtreeLength}");
// The renderer doesn't like it if we just drop the frame, so
// for now I am replacing it with comment text saying the name of the component
// but you could do something different
for (int i = 0; i < frame.ComponentSubtreeLength; i++)
{
builder.AddMarkupContent(frame.Sequence + i, $"<{frame.ComponentType.Name}/><!-- {frame.ComponentType.Name}-BBBB-->");
}
}
else
{
if (frame.Sequence >= skipTo)
{
// Put the rendered frames we want on the actual RenderTree
AddFrame !.Invoke(builder, new object[] { frame });
}
}
}
}
}
