Notes on software and the ideas behind it

Find the meaning
behind the code.

I’m Fred Yang. I write about software—how it works, why it behaves the way it does, and the ideas that make code easier to reason about.

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Working notes / 2026

Recently mapped

Architecture, reactivity, and the hidden relationships that shape frontend systems.

css

position property

In css the position properties, such as top, left, right, bottom is auto by default, one miss conception is that they are 0. Which is not the case. So when you change from positon...
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asp.net mvc

Loading common model into view

In our view, there are some data which are require across all page, such as site bar data, menu, and so on. We can split them into partial view and using Html.RenderAction. But this...
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WF

How to use bookmark in WF4

BookMark can be used to implement event driven style workflow. Below is some sample code. //in your activity, you override Execute method, to put your workflow idle protected override void Execute(NativeActivityContext context) { string...
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WF

Loading string as workflow

Here is some sample code that loads string as workflow Stream stream = new MemoryStream(ASCIIEncoding.Default.GetBytes(stringXaml)); Activity wf = ActivityXamlServices.Load(stream); IDictionary<string, object> results = WorkflowInvoker.Invoke(wf);
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WF

WF4 hosting option

WorkflowInvoker Simple "method call" style of workflow execution for short-lived worklfow (persistence is not allowed)
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