State and Reagent
State in ClojureScript is managed in the same way as Clojure applications—through the use of atoms, refs, or agents. Atoms provide uncoordinated, synchronous access to a single identity and are an excellent choice for storing the application state. Using an atom ensures that the application always sees a single, consistent view of the data.
Reagent is a ClojureScript library that provides a mechanism to update the content of a web page in response to changing the value of an atom. Markup and state are bound together, so that markup is regenerated whenever the application state is updated.
Reagent also provides syntax to render HTML in an idiomatic way using Clojure data structures. This means that both the content and the interactivity of the page can be handled in one language.
Updating state
With data held in a Reagent atom, updating the state is achieved by calling the swap! function with two arguments—the atom we wish to update and a function to transform the state of the...
