Book Image

Learning ClojureScript

By : W. David Jarvis, Allen Rohner
Book Image

Learning ClojureScript

By: W. David Jarvis, Allen Rohner

Overview of this book

Clojure is an expressive language that makes it possible to easily tackle complex software development challenges. Its bias toward interactive development has made it a powerful tool, enabling high developer productivity. In this book, you will first learn how to construct an interactive development experience for ClojureScript.. You will be guided through ClojureScript language concepts, looking at the basics first, then being introduced to advanced concepts such as functional programming or macro writing. After that, we elaborate on the subject of single page web applications, showcasing how to build a simple one, then covering different possible enhancements. We move on to study more advanced ClojureScript concepts, where you will be shown how to address some complex algorithmic cases. Finally, you'll learn about optional type-checking for your programs, how you can write portable code, test it, and put the advanced compilation mode of the Google Closure Compiler to good use.
Table of Contents (15 chapters)
Learning ClojureScript
About the Authors
About the Reviewer

Determining the size of a component

As an Om neophyte, you might be wondering what the difference is between building subcomponents and just regular functions that return HTML. Let's look at a hypothetical choice borrowed from our previous todo list example:

(defn todo-item [cursor owner] 
  (dom/div nil 
    (dom/span #js {:className (when (:done? cursor) 
      (:text )))))cursor)))) 
(defn todo-list  [cursor owner] 
  (reify om/IRender 
    (render [_] 
      (dom/div nil 
        (dom/h1 nil (:text cursor))  
        (dom/div nil 
                       (for [t (:todos cursor)] 
                          (todo-item t owner))))))) ``` 

This is a slightly modified version of our previous todo application. Here, todo-item is a standard function that happens to return virtual DOM nodes rather than an Om component constructor. It doesn't call reify. The todo-list calls the function...