core.cljs

(ns nested-routing.core
  (:require [goog.events :as events]
            [goog.history.EventType :as EventType]
            [reagent.core :as reagent]
            [reagent.ratom :refer-macros [reaction]]
            [re-frame.core :refer [dispatch dispatch-sync register-handler register-sub subscribe]]
            [secretary.core :as secretary :refer-macros [defroute]])
  (:import goog.History))

(declare route-components
         home-path
         posts-path
         post-path)

(defn outlet [route]
  (let [current-route (subscribe [:current-route])
        depth #(or (.. % -context -outletdepth) 0)]
    (reagent/create-class
     {:display-name "Outlet"

      :context-types
      #js {:outletdepth js/React.PropTypes.number}

      :child-context-types
      #js {:outletdepth js/React.PropTypes.number.isRequired}

      :get-child-context
      (fn [this]
        #js {:outletdepth (inc (depth this))})

      :reagent-render
      (fn []
        (let [this (reagent/current-component)
              index (depth this)
              components (get route-components (:name @current-route))]
          (if (> (count components) index)
            [(nth components index)]
            nil)))})))

;; queries

(defn find-post [db id]
  (first (filter (comp #{id} :id) (:posts db))))

;; subscriptions

(register-sub :current-route
  (fn [db]
    (reaction (:route @db))))

(register-sub :posts
  (fn [db]
    (reaction (:posts @db))))

(register-sub :post
  (fn [db [_ id]]
    (reaction (find-post @db id))))

(register-sub :current-post
  (fn [db]
    (let [current-route (subscribe [:current-route])]
      (reaction (find-post @db (-> @current-route :params :id))))))

;; handlers

(register-handler :initialize
  (fn [db [_ data]]
    (merge db data)))

(register-handler :navigate
  (fn [db [_ name params]]
    (assoc db :route {:name name :params params})))

;; components

(defn main []
  [:div
   [:h1
    [:a {:href (home-path)} "Nested Routing Example"]]
   [outlet]])

(defn home []
  [:a {:href (posts-path)} "View posts"])

(defn post-item [post]
  (let [current-post (subscribe [:current-post])]
    (fn [post]
      (let [active (= post @current-post)]
        [:li
         [:a {:class (if active "active" "")
              :href (post-path post)}
          (:title post)]]))))

(defn posts []
  (let [posts (subscribe [:posts])]
    (fn []
      [:div
       [:a {:href (posts-path)} "Posts:"]
       (for [post @posts]
         ^{:key (:id post)}
         [post-item post])
       [outlet]])))

(defn post-detail []
  (let [post (subscribe [:current-post])]
    (fn []
      [:p (:details @post)])))

;; routing

(def route-components
  {:home [main home]
   :post-list [main posts]
   :post-detail [main posts post-detail]})

(defroute home-path "/" []
  (dispatch [:navigate :home {}]))

(defroute posts-path "/posts" []
  (dispatch [:navigate :post-list {}]))

(defroute post-path "/posts/:id" [id]
  (dispatch [:navigate :post-detail {:id (js/parseInt id 10)}]))

;; main

(enable-console-print!)

(secretary/set-config! :prefix "#")

(def init-data {:route {:name :home
                        :params {}}
                :posts [{:id 1
                         :title "Lorem ipsum"
                         :details "Lorem ipsum dolor sit amet, consectetur adipiscing elit."}
                        {:id 2
                         :title "Morbi porta"
                         :details "Morbi porta tortor mauris, sit amet tincidunt libero malesuada nec."}]})

(dispatch-sync [:initialize init-data])

(let [h (History.)]
  (goog.events/listen h EventType/NAVIGATE #(secretary/dispatch! (.-token %)))
  (doto h (.setEnabled true)))

(reagent/render-component [outlet] (. js/document (getElementById "app")))