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;; this file is a walkthrough of Moustache features, a web framework for Clojure
;; http://github.com/cgrand/moustache/tree/master
;; Moustache allows to declare routes, apply middlewares and dispatch on http methods.
;; Moustache is compatible with all frameworks built on Ring, including Compojure
(ns demo
(:use net.cgrand.moustache)
(:use [ring.adapter.jetty :only [run-jetty]])) ;; hmmm Ring without servlets
;; set up a server that serves my-app
(declare my-app)
(def server (doto (Thread. #(run-jetty #'my-app {:port 8080})) .start))
;; #'my-app is a trick to allow to redefine my-app without restarting the server thread.
;; now define my-app
(def my-app (app ["hi"] "hello world!"))
;; go to http://localhost:8080/hi
;; our app replies to all HTTP methods, let's be more speficic:
(def my-app (app ["hi"] {:get "hello world only for GET!"}))
;; go to http://localhost:8080/hi
;; thanks to the #'my-app in the server declaration you see a magnificient "hello world only for GET!"
;; What about customizing the greeting?
(def my-app (app ["hi" name] {:get ["hello " name]}))
;; refresh http://localhost:8080/hi and you get a 404 Not found
;; go to http://localhost:8080/hi/you to admire a perfect "hello you"
;; Can I have both hi and hi/you?
(def my-app (app
["hi"] {:get "hello world only for GET!"}
["hi" name] {:get ["hello " name]}))
;; You can even greet several people at once:
(def my-app (app
["hi"] {:get "hello world only for GET!"}
["hi" & names] {:get ["hello " (apply str (interpose ", " names)) "!"]}))
;; and go to http://localhost:8080/hi/you/me/everybody
;; You can nest your apps:
(def my-app (app
["hi"] {:get "hello world only for GET!"}
["hi" &]
(app [& names] {:get ["hello " (apply str (interpose ", " names)) "!"]})))
;; thus you can write
(declare multiple-hi)
(def my-app (app
["hi"] {:get "hello world only for GET!"}
["hi" &] multiple-hi))
(def multiple-hi (app [& names] {:get ["hello " (apply str (interpose ", " names)) "!"]}))
;; now you can redefine only one small part of your application:
(def multiple-hi (app [& names] {:get ["bonjour " (apply str (interpose ", " names)) "!"]}))
;; when you simply want to nest app, there's some macro sugar: you can use a vector form instead of a (app ...) form.
(def my-app (app
["hi"] {:get "hello world only for GET!"}
["hi" &]
[[& names] {:get ["hello " (apply str (interpose ", " names)) "!"]}]))
;; the whole truth is that {} (as in {:get ...}) is also sugar:
(def my-app (app ["hi"] [:get ["hello world!"]])) ; works as well
(def my-app (app ["hi"] (app :get ["hello world!"]))) ; sugar-free
;; back on track: everybody loves regexes and falling through routes!
(def my-app (app
["hi" #"fred|lucy|ethel"] {:get ["hello!"]}
["hi" _] {:get "I don't talk to strangers"}))
;; go and try to visit http://localhost:8080/hi/you and http://localhost:8080/hi/lucy
;; you can get the result of the match
(def my-app (app
["hi" [name #"fred|lucy|ethel"]] {:get ["hello " name "!"]}
["hi" _] {:get "I don't talk to strangers"}))
;; in truth you can also write your own validators:
(defn integer [s]
(try (Integer/parseInt s) (catch Exception e)))
(def my-app (app ["countdown" [n integer]] {:get ["counting down: " (apply str (interpose " " (range n 0 -1)))]}))
;; try http://localhost:8080/countdown/42 and please note that http://localhost:8080/countdown/foo returns a 404
;; Back to our regexes
(def my-app (app
["hi" [name #"fred|lucy|ethel"]] {:get ["hello " name "!"]}
["hi" _] {:get "I don't talk to strangers"}))
;; since {:get } is a sugarized (app ...) form, we can rewrite the above def as:
(def my-app (app :get
[["hi" [name #"fred|lucy|ethel"]] ["hello " name "!"]
["hi" _] "I don't talk to strangers"]))
;; and now some examples on how to add middlewares:
(def my-app (app
(middleware1 arg1)
middleware-without-arg
:get [["hi" [name #"fred|lucy|ethel"]] ["hello " name "!"]
["hi" _] "I don't talk to strangers"]))
;; it's the same as writing:
(def my-app (->
(app :get
[["hi" [name #"fred|lucy|ethel"]] ["hello " name "!"]
["hi" _] "I don't talk to strangers"])
middleware-without-arg
(middleware1 arg1)))
;; Note that you can also declare middlewares in the vector form:
(def my-app (app
:get [(middleware1 arg1)
middleware-without-arg
["hi" [name #"fred|lucy|ethel"]] ["hello " name "!"]
["hi" _] "I don't talk to strangers"]))
;; and least but not last: every (app ... form) is a Ring handler and
;; every right-hand form can be a Ring handler.
(def my-app (app :get (fn [req] (returns a response))))
(def my-app (app ["hi"] (fn [req] (returns a response))))
(def my-app (app ["hi"] {:get (fn [req] (returns a response))}))
;; (btw if your Ring handler returns nil, the request is passed to the next route)
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