Dmitrijs Artjomenko blog: clojure

Showing posts with label clojure. Show all posts

Thursday, April 9, 2015

Using Clojure dependencies without specifying version number

Clojure has mandatory version number for dependecies, so until you are a real fan of the library, you may need to look it up somewhere. Fortunately, it is possible to specify LATEST instead of version, like:

(leiningen.exec/deps '[[http-kit "LATEST"]])
...

Clojure command line script with dependencies

If you want to use Clojure for command line scripts, the easiest way is by using lein-exec plugin. It compiles clj files on the fly and downloads all necessary dependencies that are declared in same file, similarly to Groovy @Grab annotation.

For example, if you have file named download.clj with

(leiningen.exec/deps '[[http-kit "2.1.16"]])
(require '[org.httpkit.client :as http])

(prn (:body @(http/get "http://www.google.com")))

it is possible to run it by:

lein exec download.clj

Friday, January 2, 2015

CanJS and ClojureScript

I don't really like compiled JavaScript languages, but if I had to choose - I like ClojureScript the most. It is big friends with Om MVC framework, which is based on React.js. React is another component framework like CanJS, but is too verbose to my tastes and has less features out of the box, so I like CanJS more. Only problem is that it does not have a lot of integration with ClojureScript. But it is pretty easy to solve, because ClojureScipt and CanJS are both amazing and flexible. There is example of simple component, there is ClojureScript:


(ns myexample
  (:require [domina :refer [by-id set-html!]]
            [domina.css :refer [sel]]))

(.extend can/Component
  #js {:tag "my-component"
       :scope #js {:value 3
                   :increment #(.attr % "value" (inc (.attr % "value")))}})

(set-html! (by-id "my-root") (can/view "my-template" {}))

And HTML:


<html>
<body>
  <div id="my-root"></div>
  <script type="text/mustache" id="my-template">
    <my-component>
      Value: {{value}} <input type="button" can-click="increment" value="Increment"/>
    </my-component>
  </script>
  <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.js"></script>
  <script src="http://canjs.com/release/latest/can.jquery.js"></script>
  <script src="base.js" type="text/javascript"></script>
  <script src="myexample.js" type="text/javascript"></script>
  <script type="text/javascript">goog.require("myexample");</script>
</body>
</html>