I have the following code as a test:
(defn test-fn [] (println "This is a test"))
(def my-test "test")
((resolve (symbol (str my-test "-fn"))))
Which runs as I would expect producing This is a test.
So I put it inside of a separate view like so:
(ns my-test.template-views
(:require
[hiccup.core :refer :all]
[hiccup.page :refer :all]
[my-test.home-views :refer :all]
[my-test.page1-views :refer :all]))
(defn template-body
[uri]
(html5 {:lang "en"}
[:body
(let [the-page (if (> (count uri) 1)
(clojure.string/replace uri #"/" "")
"home")]
((resolve (symbol (str the-page "-body")))))]))
Which gets called from Compojure like this:
(ns the-test.reporting-dashboard
(:gen-class)
(:require
[the-test.template-views :refer :all]
[compojure.core :refer [defroutes GET POST context]]
[compojure.route :as route]
[org.httpkit.server :refer [run-server]]
))
(defn wrap-request
[handler]
(fn [request]
(let [{remote-addr :remote-addr uri :uri scheme :scheme request-method :request-method} request]
(println (str "REQUEST: " request)))
(handler request)))
(defroutes app
(wrap-request
(GET "/" request
{:status 200
:headers {"Content-Type" "text/html"}
:body (home-views/home-body (:uri request))}))
(wrap-request
(GET "/foo" request
{:status 200
:headers {"Content-Type" "text/html"}
:body (template-body (:uri request))}))
(route/resources "/")
(route/not-found {:status 404
:headers {"Content-Type" "text/html"}
:body "<h1>Not Found</h1>"}))
When I call https//mydomain.tld/foo I get a java.lang.NullPointerException:
user=> Sat Apr 24 17:59:16 MDT 2021 [worker-2] ERROR - GET /foo
java.lang.NullPointerException
at the-test.template_views$template_body.invokeStatic(template_views.clj:14)
at the-test.template_views$template_body.invoke(template_views.clj:12)
at the-test.my_test$fn__269541.invokeStatic(my_test.clj:49)
at the-test.my_test$fn__269541.invoke(my_test.clj:46)
at compojure.core$wrap_response$fn__269102.invoke(core.clj:158)
at compojure.core$wrap_route_middleware$fn__269086.invoke(core.clj:128)
at compojure.core$wrap_route_info$fn__269091.invoke(core.clj:137)
at compojure.core$wrap_route_matches$fn__269095.invoke(core.clj:146)
at the-test.my_test$wrap_request$fn__269531.invoke(my_test.clj:22)
at compojure.core$routing$fn__269110.invoke(core.clj:185)
at clojure.core$some.invokeStatic(core.clj:2705)
at clojure.core$some.invoke(core.clj:2696)
at compojure.core$routing.invokeStatic(core.clj:185)
at compojure.core$routing.doInvoke(core.clj:182)
at clojure.lang.RestFn.applyTo(RestFn.java:139)
at clojure.core$apply.invokeStatic(core.clj:669)
at clojure.core$apply.invoke(core.clj:662)
at compojure.core$routes$fn__269114.invoke(core.clj:192)
at org.httpkit.server.HttpHandler.run(RingHandler.java:117)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
What is going on that this function is no longer able to be called when in Compojure?
Not sure about the root cause, but I was able to find a similar, minimal example and a workaround.
I created a simple project with lein new app demo, then replaced the code for core.clj with:
(ns demo.core
(:require [clojure.string :refer :all]))
(defn -main
[& args]
(println ((resolve 'capitalize) "hello")))
Running this with lein run crashes:
$ lein run
WARNING: reverse already refers to: #'clojure.core/reverse in namespace: demo.core, being replaced by: #'clojure.string/reverse
WARNING: replace already refers to: #'clojure.core/replace in namespace: demo.core, being replaced by: #'clojure.string/replace
Syntax error (NullPointerException) compiling at (/tmp/form-init1769060018979063159.clj:1:73).
null
Full report at:
/tmp/clojure-17609112051049758700.edn
The error report shows something about an error in Compiler.java so maybe it's some lazy initialization issue or just a bug. It seems to me the var cannot be resolved at the time you are attempting to call it as a function, hence the NullPointerException.
A workaround would be to use ns-resolve instead:
(ns demo.core
(:require [clojure.string :refer :all]))
(defn -main
[& args]
(println ((ns-resolve 'clojure.string 'capitalize) "hello")))
The above works as expected:
$ lein run
WARNING: reverse already refers to: #'clojure.core/reverse in namespace: demo.core, being replaced by: #'clojure.string/reverse
WARNING: replace already refers to: #'clojure.core/replace in namespace: demo.core, being replaced by: #'clojure.string/replace
Hello
See if you can replace your usage of resolve in the view with ns-resolve if you know the namespace where the symbol needs to be looked-up.
Related
I have a test:
(ns gui-proxy.handler-test
(:require [clojure.test :refer :all]
[ring.mock.request :as mock]
[gui-proxy.handler :as handler]))
(deftest test-app
(testing "not-found route"
(with-redefs-fn [handler/log-request (fn [type url] (str ""))]
(let [response (handler/app (mock/request :get "/invalid"))]
(is (= (:status response) 404))))))
and the code that are under test:
(ns gui-proxy.handler
(:require [compojure.core :refer :all]
[compojure.route :as route]
[ring.middleware.defaults :refer [wrap-defaults site-defaults]]
[clj-http.client :as client]
[gui-proxy.db :as db]))
(defn log-request [type url]
(db/insert-request-info type url))
(defn log-error []
(log-request ":fail" "fail"))
"gui-proxy - File not found")
(defroutes app-routes
(route/not-found (log-error)))
So, basically i'd like to stop the call to the database-namespace, but i end upp in a fat database exeception stacktrace...
What is wrong?
with-redefs-fn takes a map of bindings, not a vector. Note that the examples at clojuredocs use the #' reader macro to refer to the Var, so summing up you could try
(deftest test-app
(testing "not-found route"
(with-redefs-fn {#'handler/log-request (fn [type url] (str ""))}
(let [response (handler/app (mock/request :get "/invalid"))]
(is (= (:status response) 404))))))
Take a look at with-redefs it should match your usage.
http://clojuredocs.org/clojure.core/with-redefs
I'm using the below code to try and access some json input in a PUT request however what I get returned has :body {}, I'm not sure what I'm doing wrong?
(ns compliant-rest.handler
(:use compojure.core ring.middleware.json)
(:require [compojure.handler :as handler]
[compojure.route :as route]
[ring.util.response :refer [response]]
[clojure.data.json :refer [json-str]]))
(defroutes app-routes
(PUT "/searches" {body :params} (response body))
(route/resources "/")
(route/not-found "Not Found"))
(def app
(-> (handler/site app-routes)
(wrap-json-body)
(wrap-json-response)))
(app {
:request-method :put
:uri "/searches"
:content-type "application/json"
:body (with-in-str (json-str {:field "value"}))
})
;; {:status 200, :headers {"Content-Type" "application/json; charset=utf-8"}, :body "{}"}
Also, I'm new to Clojure/Lisp, any comments about my syntax and style would be appreciated.
Two things stand out:
The unparsed request body is not supposed to be a string, but an InputStream. This means your test expression won't work as is.
wrap-json-body replaces (:body request) with a clojure data structure. It does not put anything in (:params request) or (:body (:params request)). You want wrap-json-params for that.
Thanks to Joost and the comments I found there is a ring function ring.util.io.string-input-stream that does what I mistakenly thought with-in-str did. Finally I had the following working:
(ns compliant-rest.handler
(:use compojure.core ring.middleware.json)
(:require [compojure.handler :as handler]
[compojure.route :as route]
[ring.util.response :refer [response]]
[ring.util.io :refer [string-input-stream]]
[clojure.data.json :refer [json-str]]))
(defroutes app-routes
(PUT "/searches/:id" {params :params body :body}
(response body))
(route/resources "/")
(route/not-found "Not Found"))
(def app
(-> (handler/site app-routes)
(wrap-json-body)
(wrap-json-response)))
;; Example request
(app {
:request-method :put
:uri "/searches/1"
:content-type "application/json"
:body (string-input-stream (json-str {:key1 "val1"}))
})
;; {:status 200, :headers {"Content-Type" "application/json; charset=utf-8"}, :body "{\"key1\":\"val1\"}"}
It's so awesome that I can just create a simple map and call my api's entry point without needing any sort of server or mocking. I'm totally being pulled into this whole dynamic languages thing with Clojure, the repl and light table!
I'm trying to get started with Clojure and Clojurescript by implementing a simple web app. Things are going pretty good so far and reading from different tutorials I've come up with the code below:
core.clj:
(ns myapp.core
(:require [compojure.core :as compojure]
[compojure.handler :as handler]
[compojure.route :as route]
[myapp.controller :as controller]))
(compojure/defroutes app-routes
(compojure/GET "/" [] controller/index)
(route/resources "/public")
(route/not-found "Not Found"))
(def app
(handler/site app-routes))
controller.clj:
(ns myapp.controller
(:use ring.util.response)
(:require [myapp.models :as model]
[myapp.templates :as template]))
(defn index
"Index page handler"
[req]
(->> (template/home-page (model/get-things)) response))
templates.clj:
(ns myapp.templates
(:use net.cgrand.enlive-html)
(:require [myapp.models :as model]))
(deftemplate home-page "index.html" [things]
[:li] (clone-for [thing things] (do->
(set-attr 'data-id (:id thing))
(content (:name thing)))))
The problem is I can't display non-ascii characters on the page and I don't know how to set HTTP headers on a page.
I see solutions like this but I simply can't figure out where place them in my code:
(defn app [request]
{:status 200
:headers {"Content-Type" "text/plain"}
:body "Hello World"})
P.S: Any suggestions about style and/or code organization are welcome.
Use ring.util.response:
(require '[ring.util.response :as r])
Then on your index function:
(defn index
"Index page handler"
[req]
(-> (r/response (->> (template/home-page (model/get-things)) response))
(r/header "Content-Type" "text/html; charset=utf-8")))
You can chain other actions on the response such as set-cookie and whatnot:
(defn index
"Index page handler"
[req]
(-> (r/response (->> (template/home-page (model/get-things)) response))
(r/header "Content-Type" "text/html; charset=utf-8")
(r/set-cookie "your-cookie-name"
"" {:max-age 1
:path "/"})))
I copied a very basic sample from https://github.com/cgrand/enlive, but it doesn't compile:
(ns web.handler
(:require
[compojure.core :refer :all]
[compojure.handler]
[compojure.route :as route]
[net.cgrand.enlive-html :as html]))
;; Compiler throws in the next line, see the message below.
(html/deftemplate main-template "templates/index.html"
[]
[:head :title] (html/content "Enlive starter kit"))
(defroutes app-routes
(GET "/" [] "Hello")
(GET "/ping/:what" [what] (str "<h1>Ping '" what "'</h1>"))
(route/resources "/")
(route/not-found "Not Found"))
(def app
(compojure.handler/site app-routes))
Error I get:
java.lang.NullPointerException, compiling:(handler.clj:9:1)
I run with command:
lein ring server-headless
How to make it work?
EDIT
My investigation so far: error throw from enlive-html.clj:54:
(defn tagsoup-parser
"Loads and parse an HTML resource and closes the stream."
[stream]
(filter map?
(with-open [^java.io.Closeable stream stream]
(xml/parse (org.xml.sax.InputSource. stream) startparse-tagsoup)))) ; #54
Probably org.xml.sax is not referenced? How can I do this with lein?
That error normally happens when the template file is not found. With templates/index.html, it is looking in the resources/templates directory or in the src/templates directory.
I'm executing lein uberwar for my test webapp and I'm getting the following weird error:
Exception in thread "main" java.lang.ClassCastException: java.lang.Boolean cannot be cast to clojure.lang.Symbol (servlet.clj:1)
The servlet.clj contains the following:
(ns test.servlet
(:use ring.util.servlet)
(:require test.routes :as routes)
(:gen-class :extends javax.servlet.http.HttpServlet))
(defservice routes/app-routes)
The test.routes file contains:
(ns test.routes
(:use compojure.core)
(:require [compojure.route :as route]
[compojure.handler :as handler]))
(defroutes app-routes
(GET "/" [] {:status 200
:headers {"Content-Type" "text/html"}
:body "<h1>Hello World</h1>"})
(route/files "/" {:root "static"})
(ANY "/:s" [s] (str "page-not-found" s)
;; For lein ring-server
;(def test-handler
; (handler/site app-routes))
The strange thing is that if I substitute the line
(:require test.routes :as routes)
With:
(:require test.routes)
And call
(defservice test.routes/app-routes)
In servlet.clj, the WAR compiles fine and it is working flawlessly in tomcat. Is there some bug in my code that I fail to see? Why do I need to call test.routes/... instead of just routes/...?
You need to put it inside a vector:
(:require [test.routes :as routes])