Templating WIP

notes/general.org

@@ -23,3 +23,49 @@ Basic directory structure
 
 
 
+<2011-10-16 Sun 16:47>
+
+* Template Dependencies
+
+Need a way to define dependencies (html, css, javascript) locally, and
+have them bubble up to the top level:
+
+#+BEGIN_SRC
+{:html 
+#+END_SRC
+
+** HTML
+Options:
++ hiccup format [:div {:class "foo"}], etc.
+  + Allows for easier instrospection (has html? has etc).
++ String
+  + More difficult, need to use string manipulation to insert.
+
+Going with hiccup format for now.
+
+
+* Ordering
+
+Asset ordering (order of css, javascript) matters.  How am I going to
+handle this?
+
+I'd like to provide 
+
+* Escaping
+
+Have to provide a way to 'escape' templates, meaning that js and css
+tags aren't pulled out of source.
+
++ [:link {:rel "stylesheet" :href "foo.css" :escape true]
++ Require each template be wrapped in a top-level structure denoting a
+  template: 
+  - {:template [:link {:rel "stylesheet" :href "foo.css"]
+     :escape true}
+
+I kind of like the first one, but the template marker will be passed
+on to the rendered html.  Or not... Pull it from the structure on
+parsing!
+
+
+
+

project.clj

@@ -10,8 +10,9 @@
                  [net.cgrand/moustache "1.0.0"]
                  [nstools "0.2.4"]
                  [slingshot "0.2.0"]
-                 [clj-http "0.1.3"]]
-  :dev-dependencies [[swank-clojure "1.2.0"]
+                 [clj-http "0.1.3"]
+                 [midje "1.2.0"]]
+  :dev-dependencies [[swank-clojure "1.4.0-SNAPSHOT"]
                      [lein-clojars "0.6.0"]])
 
 

src/nsfw/templating.clj

@@ -0,0 +1,58 @@
+(ns nsfw.templating
+  "Dependency management for web templates."
+  (:require [clojure.zip :as zip]))
+
+(defn has-tag?
+  "DFS for tag."
+  [tag template]
+  (loop [ptr (zip/vector-zip template)]
+    (cond
+     (zip/end? ptr) false
+     (= tag (zip/node ptr)) true
+     :else (recur (zip/next ptr)))))
+
+(def has-html? (partial has-tag? :html))
+
+(defn is-stylesheet-link? [node]
+  (and (coll? node)
+       (= :link (first node))
+       (map? (second node))
+       (= "stylesheet" (get (second node) :rel))))
+
+(defn is-style-tag? [node]
+  (and (coll? node)
+       (= :style (first node))))
+
+(defn is-css-tpl? [tpl]
+  (or (is-stylesheet-link? tpl)
+      (is-style-tag? tpl)))
+
+(defn is-css-ptr? [ptr]
+  (is-css-tpl? (zip/node ptr)))
+
+(defn is-js-tpl? [node]
+  (and (coll? node)
+       (= :script (first node))
+       (map? (second node))
+       (= "text/javascript" (get (second node) :type))))
+
+(defn is-js-ptr? [ptr]
+  (is-js-tpl? (zip/node ptr)))
+
+
+(defn collect-tags [tag-pred tpl]
+  (loop [ptr (zip/vector-zip tpl)
+         css-coll []]
+    (if (zip/end? ptr)
+      {:template (zip/root ptr) :css-coll css-coll}
+      (recur (if (tag-pred ptr)
+               (zip/next (zip/remove ptr))
+               (zip/next ptr))
+             (if (tag-pred ptr)
+               (conj css-coll (zip/node ptr))
+               css-coll)))))
+
+(def collect-css (partial collect-tags is-css-ptr?))
+
+(def collect-js (partial collect-tags is-js-ptr?))
+

test/nsfw/test/templating.clj

@@ -0,0 +1,32 @@
+(ns nsfw.test.templating
+  (:use nsfw.templating :reload)
+  (:use clojure.test)
+  (:require [clojure.zip :as zip]))
+
+(deftest test-has-html?
+  (are [res template]  (= res (has-html? template))
+       true  [:html [:div.foo "bar"]]
+       true  [:div.bar [:html [:head [:title "foobar"]]]]
+       false [:div [:div [:div]]]))
+
+(deftest test-is-css-tpl?
+  (are [res template] (= res (is-css-tpl? template))
+       true  [:link {:rel "stylesheet"}]
+       true  [:style "p { color: blue; }"]
+       false [:foo [:link {:rel "stylesheet"}]]))
+
+(deftest test-is-js-tpl?
+  (are [res template] (= res (is-js-tpl? template))
+       true  [:script {:type "text/javascript"}]
+       false [:script]))
+
+(deftest test-collect-css
+  (let [res (collect-css [:html
+                          [:head
+                           [:link {:rel "stylesheet" :href "foo.css"}]
+                           [:link {:rel "stylesheet" :href "bar.css"}]]])]
+    (is (= [[:link {:rel "stylesheet" :href "foo.css"}]
+            [:link {:rel "stylesheet" :href "bar.css"}]]
+           (:css-coll res)))))
+
+