Hi James, Er, nice tip on the routes - that was another thing that I didn't expect to work but was happy when it did ;-) I will of course adapt it to your recommendation.
Speaking to the main point, no I don't want to put a channel on to the response so that's a mistake that I see and would like to avoid. I would like to understand where I have gone wrong. Maybe I need to use HTTPkit instead? Thanks Ray On Saturday, 27 September 2014 02:08:50 UTC+2, James Reeves wrote: > > Hi Ray, > > I don't entirely understand why you expected this to work. Channels aren't > a valid Ring response body. The error message is essentially telling you > that Compojure has no way of turning the channel object you've returned > into a valid response. > > The other problem you have is that the Ring Jetty adapter doesn't have any > support for asynchronous operations. > > Another small point. You're using "*" as an argument name, but this isn't > really recommended. This only works by coincidence, and it may be removed > in future versions. Instead use something like: > > (GET ["/:brand/:country/:resource" :resource #".*"] [brand country > resource] ...) > > - James > > On 27 September 2014 00:14, mond <r...@mcdermott.be <javascript:>> wrote: > >> My first core.async program ... all works outside of the web app but >> barfs once I put the functions inside a web container. I hope somebody in >> the group can point to my obvious mistake... >> >> The idea is that the function 'respond-within-sla' will give back a >> result or a come back later message after N milliseconds. It is passed a >> number of ms, three functions and the arguments for the final function ... >> which is the one that should operate within the SLA. >> >> (defn respond-within-sla [expected-result-milliseconds respond-ok >> respond-later data-fetcher & args] >> (let [data-channel (timeout expected-result-milliseconds)] >> (go (if-let [data (<!! data-channel)] >> ((async/close! data-channel) >> (respond-ok data)) >> (respond-later))) >> (go >> (>! data-channel (apply data-fetcher args))))) >> >> To keep the volume of code to parse to a minimum I have made a few toy >> functions that demonstrate the failure... >> >> ; test funcs >> >> (defn ok [data] >> (prn (str "send HTTP 200 ... got data " data))) >> >> (defn later [] >> (prn (str "send HTTP 202 ... request received, come back later"))) >> >> (defn fetcher [arg1 arg2 arg3] >> (prn (str "fetching data with args " arg1 " " arg2 " " arg3)) >> "response-data") >> >> (defn failer [& args] >> (Thread/sleep 1000) >> (str "never gets here " args)) >> >> ; test funcs >> >> (defn ok [data] >> (prn (str "send HTTP 200 ... got data " data))) >> >> (defn later [] >> (prn (str "send HTTP 202 ... request received, come back later"))) >> >> (defn fetcher [arg1 arg2 arg3] >> (prn (str "fetching data with args " arg1 " " arg2 " " arg3)) >> "response-data") >> >> (defn failer [& args] >> (Thread/sleep 1000) >> (str "never gets here " args)) >> >> (defn generate-response [brand country resource] >> (let [sla (or (env :sla-milliseconds) 100)] >> (respond-within-sla sla ok later fetcher brand country resource))) >> >> (defn generate-fail [brand country resource] >> (let [sla (or (env :sla-milliseconds) 100)] >> (respond-within-sla sla ok later failer brand country resource))) >> >> From within the REPL it all works fine... >> >> (generate-response "A" "B" "C") >> => #<ManyToManyChannel >> clojure.core.async.impl.channels.ManyToManyChannel@4b7ae3f7> >> "fetching data with args A B C" >> "send HTTP 200 ... got data response-data" >> (generate-fail "A" "B" "C") >> => #<ManyToManyChannel >> clojure.core.async.impl.channels.ManyToManyChannel@4eb8b5a9> >> "send HTTP 202 ... request received, come back later" >> >> Here is the compojure route.. >> >> (defroutes app >> (GET "/:brand/:country/*" [brand country *] >> (generate-response brand country *)) >> >> (ANY "*" [] >> (route/not-found "You must use a REST style to specify >> brand and country keys in the URL"))) >> >> If I now start it up 'lein run' and try to exercise the functions from >> the web server... >> >> $ curl -I http://localhost:5000/A/B/D.jpg >> HTTP/1.1 500 Server Error >> Date: Fri, 26 Sep 2014 23:02:03 GMT >> Content-Length: 0 >> Connection: close >> Server: Jetty(7.6.8.v20121106) >> >> And on the server I see this: >> >> $ lein run >> Compiling redirector.web >> 2014-09-27 01:01:48.426:INFO:oejs.Server:jetty-7.6.8.v20121106 >> 2014-09-27 01:01:48.458:INFO:oejs.AbstractConnector:Started >> SelectChannelConnector@0.0.0.0:5000 >> 2014-09-27 01:02:03.535:WARN:oejs.AbstractHttpConnection:/A/B/D.jpg >> java.lang.IllegalArgumentException: No implementation of method: :render >> of protocol: #'compojure.response/Renderable found for class: >> clojure.core.async.impl.channels.ManyToManyChannel >> at clojure.core$_cache_protocol_fn.invoke(core_deftype.clj:544) >> at compojure.response$fn__213$G__208__220.invoke(response.clj:9) >> at compojure.core$make_route$fn__332.invoke(core.clj:100) >> at compojure.core$if_route$fn__320.invoke(core.clj:46) >> at compojure.core$if_method$fn__313.invoke(core.clj:33) >> at compojure.core$routing$fn__338.invoke(core.clj:113) >> at clojure.core$some.invoke(core.clj:2515) >> at compojure.core$routing.doInvoke(core.clj:113) >> at clojure.lang.RestFn.applyTo(RestFn.java:139) >> at clojure.core$apply.invoke(core.clj:626) >> at compojure.core$routes$fn__342.invoke(core.clj:118) >> at clojure.lang.Var.invoke(Var.java:379) >> at >> ring.middleware.keyword_params$wrap_keyword_params$fn__534.invoke(keyword_params.clj:35) >> at >> ring.middleware.nested_params$wrap_nested_params$fn__576.invoke(nested_params.clj:84) >> at ring.middleware.params$wrap_params$fn__507.invoke(params.clj:64) >> at >> ring.middleware.multipart_params$wrap_multipart_params$fn__612.invoke(multipart_params.clj:118) >> at ring.middleware.flash$wrap_flash$fn__1286.invoke(flash.clj:35) >> at ring.middleware.session$wrap_session$fn__1273.invoke(session.clj:98) >> at ring.adapter.jetty$proxy_handler$fn__1426.invoke(jetty.clj:18) >> at >> ring.adapter.jetty.proxy$org.eclipse.jetty.server.handler.AbstractHandler$ff19274a.handle(Unknown >> >> Source) >> at >> org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116) >> at org.eclipse.jetty.server.Server.handle(Server.java:363) >> at >> org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:483) >> at >> org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:920) >> at >> org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:982) >> at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:635) >> "fetching data with args A B D.jpg" >> at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235) >> at >> org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82) >> at >> org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:628) >> at >> org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52) >> at >> org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608) >> at >> org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543) >> at java.lang.Thread.run(Thread.java:744) >> "send HTTP 200 ... got data response-data" >> >> FYI I have tested the functions prior to adding the core.async code and >> they all work fine from within Jetty and on Heroku. >> >> It seems like somehow I am getting the wrong thing put into my response. >> >> I am guessing that I have configured something wrong so here is my >> project.clj >> >> (defproject redirector "1.0.0-SNAPSHOT" >> :description "Clojure HTTP redirector" >> :url "http://redirector.herokuapp.com"; >> :license {:name "Eclipse Public License v1.0" >> :url "http://www.eclipse.org/legal/epl-v10.html"} >> :dependencies [[org.clojure/clojure "1.6.0"] >> [compojure "1.1.9"] >> [ring/ring-jetty-adapter "1.2.2"] >> [com.novemberain/monger "2.0.0"] >> [com.taoensso/carmine "2.7.0"] >> [environ "0.5.0"] >> [org.clojure/core.async "0.1.346.0-17112a-alpha"]] >> :min-lein-version "2.0.0" >> :plugins [[environ/environ.lein "0.2.1"]] >> :hooks [environ.leiningen.hooks] >> :main "redirector.web" >> :aot :all >> :uberjar-name "redirector-standalone.jar" >> :profiles {:production {:env {:production true}}}) >> >> Any ideas, help would be greatly appreciated. >> >> Thanks >> >> Ray >> >> >> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com >> <javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <javascript:> >> For more options, visit this group at >> http://groups.google.com/group/clojure?hl=en >> --- >> You received this message because you are subscribed to the Google Groups >> "Clojure" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to clojure+u...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
