In this series, I will explore programming techniques for the notebook platform Observable. Today I am looking at how to direct a reactive Dataflow stream to one-of-n downstream cells. This article assumes you are familiar with Observable's non-linear reactive program flow already.

Sometimes we want control the dataflow with logic. If we have a cell called data streaming values, we might like to direct those updates to either cell_1 or cell_2.

You can programatically trigger dataflow by calling dispatchEvent on its enclosing view.

You can create a lightweight view with Inputs.input

Now dataflow is guided by the value of the choice variable.

Give it a try on the live notebook at @tomlarkworthy/switch-dataflow

I hope you find that useful and that you find other useful ways to manipulate dataflow!