feat(API): response paging

2 files changed, 44 insertions, 36 deletions

diff --git a/src/weepinbell/handler.clj b/src/weepinbell/handler.clj
index a4b69fc..0040fcd 100644
--- a/src/weepinbell/handler.clj
+++ b/src/weepinbell/handler.clj
@@ -15,13 +15,13 @@
 
 (defmacro defmention-routes [base-path mention-type]
   `(context ~base-path []
-     (GET "/" [~'url] (retriever/by-url ~'url ~mention-type))
-     (GET "/:domain" [~'domain] (retriever/by-domain ~'domain ~mention-type))))
+     (GET "/" [~'url ~'page] (retriever/by-url ~'url ~mention-type ~'page))
+     (GET "/:domain" [~'domain ~'page] (retriever/by-domain ~'domain ~mention-type ~'page))))
 
 (defroutes api-routes
   (GET "/" [target] (ui/home (get-config :allowed-target-domains)
-                       (get-config :endpoint)
-                       target))
+                             (get-config :endpoint)
+                             target))
   ;; receiver endpoint
   (POST (get-config :endpoint) [source target]
     (receive {:s source :t target} wmc))
diff --git a/src/weepinbell/retriever.clj b/src/weepinbell/retriever.clj
index 20ff686..de0d436 100644
--- a/src/weepinbell/retriever.clj
+++ b/src/weepinbell/retriever.clj
@@ -3,10 +3,12 @@
             [weepinbell.utils :refer [get-domain]]
             [weepinbell.microformats-wrapper :as mf-wrapper]))
 
+(def default-page-size 12)
+
 ;; utilities
 (defn- respond-webmention-json [data]
-  (if data 
-    {:status 200 
+  (if data
+    {:status 200
      :headers {"Content-Type" "application/json; charset=utf-8"}
      :body data}
     ;; if no data found, respond 404
@@ -15,20 +17,30 @@
      :body {:status 404
             :message "Webmention does not exist or is pending for verification."}}))
 
-(defn- respond-webmention-list-json [data]
-  {:status 200
-   :headers {"Content-Type" "application/json; charset=utf-8"}
-   :body data})
+(defn- respond-webmention-list-json
+  ([data]
+   (respond-webmention-list-json nil nil data))
+  ([page data]
+   (respond-webmention-list-json page default-page-size data))
+  ([page page-size data]
+   (let [page (Integer/parseInt page)]
+     {:status 200
+      :headers {"Content-Type" "application/json; charset=utf-8"}
+      :body (if (or (nil? page) (< page 0)) data
+              ;; if page number is provided
+              ;; partition and return page frame 
+                (-> (partition-all page-size data)
+                    (nth page)))})))
 
 (defn- wrap-response-object [data]
   (let [result {:webmention (:webmention data)}]
     (cond-> result
       (not (empty? (:microformats data)))
-        (assoc :microformats (-> data
-                                 :microformats
-                                 mf-wrapper/wrap-entry))
+      (assoc :microformats (-> data
+                               :microformats
+                               mf-wrapper/wrap-entry))
       (:extra data)
-        (assoc :extra (:extra data)))))
+      (assoc :extra (:extra data)))))
 
 (defn- wrap-response-list [data]
   (map wrap-response-object data))
@@ -48,31 +60,27 @@
 
 (defn by-domain
   "Get webmentions sent to a particular domain."
-  ([domain]
-    (by-domain domain nil))
-  ([domain typ]
-    (cond->> (storage/get-wms-by-domain domain)
-      true wrap-response-list
-      typ  (filter-response-by-mftype typ)
-      true respond-webmention-list-json)))
+  [domain typ page]
+  (cond->> (storage/get-wms-by-domain domain)
+    true wrap-response-list
+    typ  (filter-response-by-mftype typ)
+    true (respond-webmention-list-json page)))
 
 (defn by-url
   "Get webmention sent to a particular URL."
-  ([url]
-    (by-url url nil))
-  ([url typ]
-    (if url
-      (cond->> (get-domain url)
-         true storage/get-wms-by-domain
-         true (filter #(= url (get-in % [:webmention :target])))
-         true wrap-response-list
-         typ  (filter-response-by-mftype typ)
-         true respond-webmention-list-json)
-      ;; if no url query is passed
-      {:status 400
-       :headers {"Content-Type" "application/json; charset=utf-8"}
-       :body {:status 400
-              :message "Missing URL. Specify target URL whose webmentions you are querying."}})))
+  [url typ page]
+  (if url
+    (cond->> (get-domain url)
+      true storage/get-wms-by-domain
+      true (filter #(= url (get-in % [:webmention :target])))
+      true wrap-response-list
+      typ  (filter-response-by-mftype typ)
+      true (respond-webmention-list-json page))
+    ;; if no url query is passed
+    {:status 400
+     :headers {"Content-Type" "application/json; charset=utf-8"}
+     :body {:status 400
+            :message "Missing URL. Specify target URL whose webmentions you are querying."}}))
 
 (defn by-id
   "Get one specific webmention by ID."