Maximize share links to firefox's maximum displayable URL length (#80)

src/clj/metafacture_playground/server.clj

@@ -7,4 +7,4 @@
  (defn -main [& _args]
    (let [port (or (env :port) 3000)]
      (println "Start server with port " port)
-     (run-jetty #'handler {:port port :join? false})))
+     (run-jetty #'handler {:port port :join? false :request-header-size 65536})))

src/cljs/metafacture_playground/events.cljs

@@ -6,7 +6,7 @@
    [re-frame.core :as re-frame]
    [day8.re-frame.fetch-fx]
    [jtk-dvlp.re-frame.readfile-fx]
-   [lambdaisland.uri :refer [uri join assoc-query* query-encode]]
+   [lambdaisland.uri :refer [uri join assoc-query*]]
    [com.degel.re-frame.storage]
    [clojure.string :as clj-str]
    [clojure.walk :as walk]
@@ -263,61 +263,60 @@
         data-in-flux? (merge {:data data})))
     {}))
 
-(defn- count-query-string [params]
-  (reduce
-   (fn [result [k v]]
-     (if v
-       (+ result
-          (-> k name count)
-          2                ;; '&' before key + '=' after key
-          (-> v query-encode count))
-       result))
-   0
-   params))
-
-(defn- query-string-too-long? [params maximum]
-  (try
-    (> (count-query-string params)
-       maximum)
-    (catch js/RangeError _
-      true)))
+(def max-url-string 65536) ; maximum displayable URL length in Firefox
+
+(defn- url-too-long? [url]
+  (if-not (:error url)
+    (> (count url) max-url-string)
+    true))
 
 (defn generate-link [url path query-params]
   (let [inputs (-> query-params
                    (dissoc :active-editor)
                    vals)]
     (when-not (every? clj-str/blank? inputs)
-      (-> (uri url)
-          (join path)
-          (assoc-query* query-params)
-          str))))
+      (try
+        (-> (uri url)
+            (join path)
+            (assoc-query* query-params)
+            str)
+        (catch js/Error _
+          {:error true})))))
+
+(defn add-error-message [result name url]
+  (if (:error url)
+    (conj result (str "It occured an JS Error generating the " name"."))
+    (conj result (str "The " name " is "
+                      (- max-url-string (count url))
+                      " characters too long (Maximum: " max-url-string ")"))))
+
+(defn firefox-used? []
+  (> (-> js/navigator .-userAgent (.indexOf "Firefox"))
+     -1))
 
 (defn generate-links
   [{db :db} [_ url data flux fix morph active-editor]]
-  (let [max-query-string 1536
-        max-url-string 2048
-        api-call-params (when flux
+  (let [api-call-params (when flux
                           (merge
                            {:flux flux}
                            (get-used-params flux fix morph data)))
         workflow-params (merge api-call-params
                                (when active-editor
                                  {:active-editor (name active-editor)}))
-        api-call-query-string-too-long? (query-string-too-long? api-call-params max-query-string)
-        workflow-query-string-too-long? (query-string-too-long? workflow-params max-query-string)
-        api-call-link (when (and api-call-params (not api-call-query-string-too-long?))
-                        (generate-link url "./process" api-call-params))
-        workflow-link (when (and workflow-params (not workflow-query-string-too-long?))
-                        (generate-link url "" workflow-params))
-        url-string-too-long? (or (> (count api-call-link) max-url-string)
-                                 (> (count workflow-link) max-url-string))
-        message (when (or api-call-query-string-too-long? workflow-query-string-too-long? url-string-too-long?)
-                  {:content "Share links for large workflows are not supported yet"
+        api-call-link (when api-call-params (generate-link url "./process" api-call-params))
+        workflow-link (when workflow-params (generate-link url "" workflow-params))
+        api-call-link-too-long? (url-too-long? api-call-link)
+        workflow-link-too-long? (url-too-long? workflow-link)
+        message (when (or api-call-link-too-long? workflow-link-too-long?)
+                  {:content (cond-> ["There was a problem generating the share links:"]
+                              api-call-link-too-long? (add-error-message "api call link" api-call-link)
+                              workflow-link-too-long? (add-error-message "workflow link" workflow-link)
+                              (not (firefox-used?)) (conj "Consider using Firefox."))
                    :type :warning})]
     {:db (-> db
              (assoc :message message)
-             (assoc-in [:links :api-call] (when-not url-string-too-long? api-call-link))
-             (assoc-in [:links :workflow] (when-not url-string-too-long? workflow-link)))}))
+             (assoc-in [:links :api-call] (when-not api-call-link-too-long? api-call-link))
+             (assoc-in [:links :workflow] (when-not workflow-link-too-long? workflow-link)))}))
 
 (re-frame/reg-event-fx
  ::generate-links

test/cljs/metafacture_playground/event_handler_test.cljs

@@ -174,23 +174,12 @@
            (is (= (-> workflow-link :query query-string->map :morph) morph))
            (is (= (:path workflow-link) "/playground/")))))
 
-  (testing "Test not generating links if parameters are too long"
-    (let [db' (-> empty-db
-                  (events/edit-value [:edit-value :flux (generate-random-string 1537)]))
-          flux (get-in db' [:db :input-fields :flux :content])
-          db'' (-> db'
-                   (events/generate-links [:generate-links "http://test.metafacture.org/playground/" nil flux nil nil :fix])
-                   :db)]
-      (and (is (= (get-in db'' [:message :content]) "Share links for large workflows are not supported yet"))
-           (is (nil? (get-in db'' [:links :api-call])))
-           (is (nil? (get-in db'' [:links :workflow]))))))
-
   (testing "Test not generating links if url is too long"
-    (let [extra-long-test-url (str "http://test.metafacture.org/playground/" (generate-random-string 1671) "/")
+    (let [extra-long-test-url (str "http://test.metafacture.org/playground/" (generate-random-string 66000) "/")
           db'' (-> empty-db
                    (events/generate-links [:generate-links extra-long-test-url (:data sample-data) (:flux sample-data) (:fix sample-data) "" :fix])
                    :db)]
-      (and (is (= (get-in db'' [:message :content]) "Share links for large workflows are not supported yet"))
+      (and (is (get-in db'' [:message :content]))
            (is (nil? (get-in db'' [:links :api-call])))
            (is (nil? (get-in db'' [:links :workflow])))))))