Frontend routing implementation

.gitignore

@@ -1,4 +1,4 @@
-/target
+target/
 /classes
 /checkouts
 pom.xml

modules/reitit-frontend/project.clj

@@ -0,0 +1,9 @@
+(defproject metosin/reitit-frontend "0.1.3"
+  :description "Reitit: Clojurescript frontend routing core"
+  :url "https://github.com/metosin/reitit"
+  :license {:name "Eclipse Public License"
+            :url "http://www.eclipse.org/legal/epl-v10.html"}
+  :plugins [[lein-parent "0.3.2"]]
+  :parent-project {:path "../../project.clj"
+                   :inherit [:deploy-repositories :managed-dependencies]}
+  :dependencies [[metosin/reitit-core]])

modules/reitit-frontend/src/reitit/frontend.cljs

@@ -0,0 +1,90 @@
+(ns reitit.frontend
+  "Utilities to implement frontend routing using Reitit.
+
+  Controller is way to declare as data the side-effects and optionally
+  other data related to the route."
+  (:require [reitit.core :as reitit]
+            [clojure.string :as str]
+            goog.Uri
+            [reitit.coercion :as coercion]))
+
+;;
+;; Utilities
+;;
+
+(defn query-params
+  "Parse query-params from URL into a map."
+  [^goog.Uri uri]
+  (let [q (.getQueryData uri)]
+    (->> q
+         (.getKeys)
+         (map (juxt keyword #(.get q %)))
+         (into {}))))
+
+(defn get-hash
+  "Given browser hash starting with #, remove the # and
+  end slashes."
+  []
+  (-> js/location.hash
+      (subs 1)
+      (str/replace #"/$" "")))
+
+;;
+;; Controller implementation
+;;
+
+(defn get-params
+  "Get controller parameters given match. If controller provides :params
+  function that will be called with the match. Default is nil."
+  [controller match]
+  (if-let [f (:params controller)]
+    (f match)))
+
+(defn apply-controller
+  "Run side-effects (:start or :stop) for controller.
+  The side-effect function is called with controller params."
+  [controller method]
+  (when-let [f (get controller method)]
+    (f (::params controller))))
+
+(defn- pad-same-length [a b]
+  (concat a (take (- (count b) (count a)) (repeat nil))))
+
+(defn apply-controllers
+  "Applies changes between current controllers and
+  those previously enabled. Resets controllers whose
+  parameters have changed."
+  [old-controllers new-match]
+  (let [new-controllers (map (fn [controller]
+                               (assoc controller ::params (get-params controller new-match)))
+                             (:controllers (:data new-match)))
+        changed-controllers (->> (map (fn [old new]
+                                        ;; different controllers, or params changed
+                                        (if (not= old new)
+                                          {:old old, :new new}))
+                                      (pad-same-length old-controllers new-controllers)
+                                      (pad-same-length new-controllers old-controllers))
+                                 (keep identity)
+                                 vec)]
+    (doseq [controller (map :old changed-controllers)]
+      (apply-controller controller :stop))
+    (doseq [controller (map :new changed-controllers)]
+      (apply-controller controller :start))
+    new-controllers))
+
+(defn hash-change [router hash]
+  (let [uri (goog.Uri/parse hash)
+        match (or (reitit/match-by-path router (.getPath uri))
+                  {:data {:name :not-found}})
+        q (query-params uri)
+        ;; Coerce if coercion enabled
+        c (if (:result match)
+            (coercion/coerce-request (:result match) {:query-params q
+                                                      :path-params (:params match)})
+            {:query q
+             :path (:param match)})
+        ;; Replace original params with coerced params
+        match (-> match
+                  (assoc :query (:query c))
+                  (assoc :params (:path c)))]
+    match))

modules/reitit/project.clj

@@ -11,4 +11,6 @@
                  [metosin/reitit-spec]
                  [metosin/reitit-schema]
                  [metosin/reitit-swagger]
-                 [metosin/reitit-swagger-ui]])
+                 [metosin/reitit-swagger-ui]
+                 [metosin/reitit-frontend]
+                 [metosin/reitit-re-frame]])

project.clj

@@ -16,6 +16,7 @@
                          [metosin/reitit-schema "0.1.3"]
                          [metosin/reitit-swagger "0.1.3"]
                          [metosin/reitit-swagger-ui "0.1.3"]
+                         [metosin/reitit-frontend "0.1.3"]
 
                          [meta-merge "1.0.0"]
                          [ring/ring-core "1.6.3"]
@@ -40,7 +41,8 @@
                                   "modules/reitit-spec/src"
                                   "modules/reitit-schema/src"
                                   "modules/reitit-swagger/src"
-                                  "modules/reitit-swagger-ui/src"]
+                                  "modules/reitit-swagger-ui/src"
+                                  "modules/reitit-frontend/src"]
 
                    :dependencies [[org.clojure/clojure "1.9.0"]
                                   [org.clojure/clojurescript "1.10.238"]

scripts/lein-modules

@@ -3,6 +3,6 @@
 set -e
 
 # Modules
-for ext in reitit-core reitit-ring reitit-spec reitit-schema reitit-swagger reitit-swagger-ui reitit; do
+for ext in reitit-core reitit-ring reitit-spec reitit-schema reitit-swagger reitit-swagger-ui reitit-frontend reitit; do
   cd modules/$ext; lein "$@"; cd ../..;
 done