I'm experimenting with using noir to start three servers (each to handle a different aspect of the application). I am trying to do this so that I can run all three servers within one application while developing and easily decouple the project into three different applications for deployment.
It is no problem to use noir.server/start and noir.server/stop to run the jetty servers I need.
What I'm trying to figure out is some way to call load-views (or something like that) with a different set views for each server so that URI conflicts are handled by the correct defpage.
I found a solution that works by clearing noir.core/noir-routes, noir.core/route-funcs, noir.core/pre-routes, and noir.core/post-routes. I have an example below of a namespace that starts three servers all with their own views.
(ns my-three.server
(:require
[noir.core :as noir]
[noir.server :as server]))
(def ^:dynamic *servers* (atom {}))
(defn clear-routes []
(do
(reset! noir/noir-routes {})
(reset! noir/route-funcs {})
(reset! noir/pre-routes (sorted-map))
(reset! noir/post-routes [])
nil))
(defn start-server [port mode]
(if-let [s (#*servers* port)]
(println "Server already running on port" port)
(swap! *servers* assoc port (server/start port {:mode mode}))))
(defn stop-server [port]
(let [s (#*servers* port)]
(server/stop s)
(swap! *servers* dissoc port)))
(defn stop-all []
(doall (map stop-server (keys #*servers*))))
(defn -main [& m]
(let [mode (if (nil? (first m)) :prod (first m))]
(server/load-views "src/my_three/views/web/" )
(start-server 8080 mode)
(clear-routes)
(server/load-views "src/my_three/views/mobile_downstream/")
(start-server 8081 mode)
(clear-routes)
(server/load-views "src/my_three/views/mobile_upstream/")
(start-server 8082 mode)))
Related
Given Java instance obj and a member name (string) "Foo", and a map conf, I am trying to generate Clojure code that will look like this:
(if (get conf "Foo")
(set! (.Foo obj) (get conf "foo")
obj)
And also, if I know that "SomeEnum" is a Java enum name, a code like this:
(if (get conf "SomeEnum")
(set! (.someEnum obj)(Enum/valueOf SomeEnum (get conf "SomeEnum")))
obj)
Here is what I came up with:
(defmacro set-java [obj conf obj-name]
`(if (get ~conf ~obj-name)
(set! (. ~obj ~(symbol obj-name)) (get ~conf ~obj-name))
~obj))
(defn lowercase-first [s]
(apply str (Character/toLowerCase (first s)) (rest s)))
(defmacro set-java-enum [obj conf obj-name]
`(if (get ~conf ~obj-name)
(set! (. ~obj ~(symbol (lowercase-first obj-name)))
(Enum/valueOf ~(symbol obj-name) (get ~conf ~obj-name)))
~obj))
Testing with macroexpand seems to give the right result, but after trying:
(defn ^Policy map->policy [conf]
(-> (Policy.)
(set-java-enum conf "CommitLevel")
(set-java conf "durableDelete")
(set-java conf "expiration")
(set-java conf "generation")
(set-java-enum conf "GenerationPolicy")
(set-java-enum conf "RecordExistsAction")
(set-java conf "respondAllOps")))
I got a weird endless loop of reflection warnings.
--- edit ---
after battelling with that for quite a while, I gave up threading (->) and ended with:
(defmacro set-java [obj conf obj-name]
`(when (get ~conf ~obj-name)
(set! (. ~obj ~(symbol obj-name)) (get ~conf ~obj-name))))
(defn lowercase-first [s]
(apply str (Character/toLowerCase ^Character (first s)) (rest s)))
(defmacro set-java-enum [obj conf obj-name]
`(when (get ~conf ~obj-name)
(set! (. ~obj ~(symbol (lowercase-first obj-name)))
(Enum/valueOf ~(symbol obj-name) (get ~conf ~obj-name)))))
(defn map->write-policy [conf]
(let [wp (WritePolicy. (map->policy conf))]
(set-java-enum wp conf "CommitLevel")
(set-java wp conf "durableDelete")
;; more non threaded object manipulation
wp))
So I am still not sure what was the reflection warning endless loop about, but this is hopefully handful as well, and can be improved further.
I think this is due to your interpolating ~obj multiple times in each macro. Is your "loop" actually endless, or is it just ~128 or ~256 steps long?
In any case, the fix for that particular issue (whether or not it's the root cause of the problem you describe) is to wrap the form in (let [obj# ~obj] ...) and then refer to obj# below, so the argument is only interpolated once.
You can (should!) do this with conf and obj-name too, but they're probably not actively causing problems, at least with the usage code you provided.
Here's a simple re-frame app that I tried to create based on the existing example project in re-frame's github repo. But it is only displaying things from the html file. Seems like no event is being dispatched. Can anyone point out what am I doing wrong? Thanks.
(ns simple.core
(:require [reagent.core :as reagent]
[re-frame.core :as rf]
[clojure.string :as str]))
(rf/reg-event-db
:rand
(fn [db [_ _]]
(assoc db :winner ( + 2 (rand-int 3)))))
(rf/reg-sub
:winner
(fn [db _]
(:winner db)))
(def participants ["Alice" "Bob" "Ellie"])
(defn winners-name
[idx]
(get participants idx))
(defn show-winner
[]
[:h1
(winners-name
(#(rf/subscribe [:winner])))])
(defn ui
[]
[:div
[:h1 "Lottery"]
[show-winner]])
(defn ^:export run
[]
(rf/dispatch-sync [:rand])
(reagent/render [ui]
(js/document.getElementById "app")))
The :rand handler will produce nil most times since you are adding 2 to the generated value and the participants vector only has 3 entries.
The issue is caused because of a pair of extra parenthesis around the deref thing. So the function winners-name is treating it as a list instead of an integer.
(winners-name
(#(rf/subscribe [:winner]))
I'm having some trouble to get started with Light Table.
Here's my code (Clojure)
(ns prova1-ed.core
(:gen-class))
(use 'clojure.java.io)
(defn -main [& args]
(println "Type the name of the file to read: ")
(let [fileName (read-line)]
(let [rdr (reader fileName)]
(doseq [line (line-seq rdr)]
(println line)
)))
)
I'm sure it works. I've tested with lein run. As you can see, the program should read a file which the name is given by the user.
I've tried CTRL+SPACE in Light Table, but this is what I receive:
ERROR: Unhandled REPL handler exception processing message {:data {:auto? false, :pos {:line 14, :ch 1}, :mime "text/x-clojure", :tags [:editor.clj :editor.clojure], :type-name "Clojure", :line-ending "\r\n", :ns user, :path "C:\\Users\\Tiago\\Documents\\Clojure\\prova1_ed\\src\\prova1_ed\\core.clj", :print-length nil, :name "core.clj", :local true, :code "(ns prova1-ed.core\n (:gen-class))\n\n(use 'clojure.java.io)\n\n(defn -main [& args]\n\n (println \"Type the name of the file to read: \")\n\n (let [fileName (read-line)]\n (let [rdr (reader fileName)]\n (doseq [line (line-seq rdr)]\n (println line)\n )))\n)\n"}, :id 90, :op editor.eval.clj.sonar, :session 65d1da68-a730-4ffe-9365-9527726384e3}
How can i run it in the Light Tables' enviroment, so that I can input the file name?
TLDR
I don't think you can run (read-line) in Light Table as it'd have to add explicit support for allowing input. There's no standard input basically.
An Alternative
I'd suggest you modify your -main function to accept an explicit file-name argument instead of trying to read it from a standard input that isn't available.
I've got a Clojure webapp that I work on in Light Table.
I've got a -main function in a namespace named my-app.web. It looks something like this:
(defn -main [& [port]]
(let [port (Integer. (or port (env :port) 5000))
store (cookie/cookie-store {:key (env :session-secret)})]
(jetty/run-jetty (-> #'secured-app
wrap-with-logging
wrap-current-user
wrap-current-auth
wrap-error-page
(site {:session {:store store}}))
{:port port :join? false})))
In a separate file I've named light-table-start.clj, I've got the following code to run my app inside Light Table:
(require '[my-app.web :as web])
(require '[ring.adapter.jetty :as jetty])
(defonce server (web/-main "5000"))
;; (.start server)
;; (.stop server)
I run the Eval: Eval editor contents command (Ctrl+Shift+Enter on Windows and Linux or ⌘+Shift+Enter on Mac OS) the first time I want to run my app (or later, if the connection is closed for some reason). When I want to start or stop the server I can just highlight the code on the respective commented lines and run the Eval: Eval a form in editor command (Ctrl+Enter on Windows and Linux or ⌘+Enter on Mac OS).
EDIT: Turned out I was using require instead of :require in the namespace declaration. With :require, tools.namespace refreshes the logging namespace, and the problem goes away. I still find it curious, however, that the expression (eval `(var ~(symbol "A/func"))) does not work in the situation described below (that is, if B below is not refreshed).
Summary: I'm using tools.namespace. If I have namespaces A and B, and in B do (eval `(var ~(symbol "A/func"))), and (tools.namespace/refresh) and run the code, that works. But if I make a change to A, do (tools.namespace/refresh), so that only A refreshes, then running that expression gives the error: Cannot resolve var: A/func in this context, even though A/func exists. Why?
Longer version:
In my project, I have a logging module/namespace that uses robert-hooke (see below). I'm using tools.namespace to reload my code when I make changes.
The problem is the following: When I want to log (my logging currently just prints) something, I list the functions that I want to log in my logging namespace and do (t.n/refresh). That works. But if I make changes to the the namespaces that contain the functions that I want to log, and do (t.n/refresh) without making changes to the logging namespace, the logging no longer works (for the functions that have been refreshed). As soon as I make a change to logging, so that it too is refreshed by tools.namespace, it starts working again.
So, it's like the vars in namespaces that have been refreshed don't properly get their logging hooks. But I don't understand why.
Below is my logging namespace. I call add-logging-wrappers each time I run my program.
If I add (eval `(var ~(symbol "sv/register-damage"))) inside add-logging-wrappers, that's fine when logging has just been refreshed and the logging works. But those times the logging does not work, that expression causes the error Cannot resolve var: sv/register-damage in this context.
(ns game.logging
(require [robert.hooke :as rh]
[clojure.pprint :as pp]
[game.server.core :as sv]
[game.client.core :as cl]
[game.math :as math]
(game.common [core-functions :as ccfns]
[graphics :as gfx])
(game.server [pathfinding :as pf]))
(:use [game.utils]))
(defn log-println [name type object]
(println (str (current-thread-name) " // " name " " type ":\n"
(with-out-str
(pp/pprint object)))))
(defn print-output [name f & args]
(let [result (apply f args)]
(log-println name "output" result)
result))
(defn print-input [name f & args]
(log-println name "input" args)
(apply f args))
(defn print-call [name f & args]
(println (str (current-thread-name) "//" name))
(apply f args))
(defmacro make-name-var-list [fn-list]
`[~#(for [fn fn-list]
[(str fn) `(var ~fn)])])
(defmacro defloglist [name & fns]
`(def ~name (make-name-var-list [~#fns])))
(defn add-hooks [name-vars & wrappers]
(when (seq wrappers)
(doseq [[name var] name-vars]
(rh/add-hook var (partial (first wrappers) name)))
(recur name-vars (next wrappers))))
(defn get-ns-name-vars [ns-sym]
(-> (the-ns ns-sym) (#(.name %)) ns-interns))
(defn add-hooks-to-ns [ns-sym & wrappers]
(apply add-hooks (get-ns-name-vars ns-sym) wrappers))
(defloglist log-both
sv/distribute-exp ;; <--- things to log
sv/register-damage
sv/give-exp)
(defloglist log-input)
(defloglist log-output)
(defn add-logging-wrappers []
(dorun (->> (all-ns) (map #(.name %)) (mapcat ns-interns) (map second)
(map rh/clear-hooks)))
(add-hooks log-both print-output print-input)
(add-hooks log-input print-input)
(add-hooks log-output print-output))
I want a map in an atom that can keep track of times as Unix time stamps.
So, in my main function I have:
(defn -main [& args]
(println "Server is starting")
(def port (Integer/parseInt (first args)))
(def registry (atom {}))
(run-server port who-is-here registry))
And inside of run-server I have a call to add-to-logged-in-registry:
(defn add-to-logged-in-registry
[registry]
(let [moments (Date.)
right-now (.getTime moments)]
(swap! registry conj right-now)))
This last line gives me this error:
Exception in thread "main" java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Long
at clojure.lang.RT.seqFrom(RT.java:487)
at clojure.lang.RT.seq(RT.java:468)
at clojure.lang.APersistentMap.cons(APersistentMap.java:39)
at clojure.lang.RT.conj(RT.java:544)
at clojure.core$conj.invoke(core.clj:83)
at clojure.lang.Atom.swap(Atom.java:51)
at clojure.core$swap_BANG_.invoke(core.clj:2107)
at who_is_logged_in.core$add_to_logged_in_registry.invoke(core.clj:39)
at who_is_logged_in.core$listen_and_respond.invoke(core.clj:42)
at who_is_logged_in.core$run_server.invoke(core.clj:52)
at who_is_logged_in.core$_main.doInvoke(core.clj:76)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at who_is_logged_in.core.main(Unknown Source)
What does this mean?
When I try this at the REPL in emacs, this works perfectly:
user> (def registry (atom []))
#'user/registry
user> (let [moments (Date.)
right-now (.getTime moments)]
(swap! registry conj right-now))
[1345698128988]
user> (let [moments (Date.)
right-now (.getTime moments)]
(swap! registry conj right-now))
[1345698128988 1345698132472]
conj behaves differently depending on the type of collection it is adding elements to. In your first example it is adding elements to a map and needs A key and a value in a collection. In your REPL example it is adding elements to a vector and needs only a single value.
swap!ing into a map:
(def registry (atom{}))
(let [moments (java.util.Date.)
right-now (.getTime moments)]
(swap! registry conj [:time right-now]))
{:time 1345700872898}