public void RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, out Exception?renderFragmentException)
{
renderFragmentException = null;
// A component might be in the render queue already before getting disposed by an
// earlier entry in the render queue. In that case, rendering is a no-op.
if (_componentWasDisposed)
{
return;
}
_nextRenderTree.Clear();
try
{
renderFragment(_nextRenderTree);
}
catch (Exception ex)
{
// If an exception occurs in the render fragment delegate, we won't process the diff in any way, so child components,
// event handlers, etc., will all be left untouched as if this component didn't re-render at all. The Renderer will
// then forcibly clear the descendant subtree by rendering an empty fragment for this component.
renderFragmentException = ex;
return;
}
// We don't want to make errors from this be recoverable, because there's no legitimate reason for them to happen
_nextRenderTree.AssertTreeIsValid(Component);
// Swap the old and new tree builders
(CurrentRenderTree, _nextRenderTree) = (_nextRenderTree, CurrentRenderTree);
var diff = RenderTreeDiffBuilder.ComputeDiff(
_renderer,
batchBuilder,
ComponentId,
_nextRenderTree.GetFrames(),
CurrentRenderTree.GetFrames());
batchBuilder.UpdatedComponentDiffs.Append(diff);
batchBuilder.InvalidateParameterViews();
}
