Fix boolean attrs

CHANGELOG.md

@@ -7,6 +7,8 @@ Unreleased changes are available via `io.github.borkdude/html {:git/sha "..."}`
 ## Unreleased
 
 - Fix shorthand classes being dropped when the attribute map has no `:class`: `[:div.card {:id "a"}]` rendered `<div id="a">`. The same path interpolated a symbol's _name_ when `:class` was bound to an expression, so `(let [x "big"] [:div.card {:class x}])` rendered `class="card x"`.
+- Omit an attribute whose value is `nil` or `false`. `[:input {:disabled false}]` rendered `disabled="false"`, which — HTML boolean attributes being presence-based — disabled the element. An attribute map that now renders to nothing no longer leaves a stray space (`<div >`), which also fixes `[:div {}]`.
+- Render `aria-*` booleans as the strings `"true"` and `"false"`. ARIA attributes are string-valued enumerations in which absence is a distinct state, so `[:button {:aria-expanded false}]` must render `aria-expanded="false"` rather than being omitted, and `true` must render `aria-expanded="true"` rather than a bare attribute (whose empty value is invalid, and falls back to the attribute's default). `nil` still omits.
 
 ## 0.2.6
 

src/borkdude/html.cljc

@@ -37,19 +37,29 @@
   ([opts m]
    (let [xml? (= :xml (:mode opts))]
      (str/join " "
-               (map (fn [[k v]]
-                      (if (and (true? v) (not xml?))
-                        (name k)
-                        (str (name k)
-                             "=" (cond (string? v) (pr-str (escape-html v))
-                                       (keyword? v) (pr-str (name v))
-                                       (and (map? v) (= "style" (name k))) (pr-str (escape-html (->css v)))
-                                       :else (pr-str (escape-html (str v)))))))
-                    m))))
+               (keep (fn [[k v]]
+                       (let [k     (name k)
+                             aria? (str/starts-with? k "aria-")]
+                         (cond
+                           (nil? v) nil
+                           (and (false? v) (not aria?)) nil
+                           (and (true? v) (not xml?) (not aria?)) k
+                           :else
+                           (str k
+                                "=" (cond (string? v) (pr-str (escape-html v))
+                                          (keyword? v) (pr-str (name v))
+                                          (and (map? v) (= "style" k)) (pr-str (escape-html (->css v)))
+                                          :else (pr-str (escape-html (str v))))))))
+                     m))))
   ([opts m base-map]
    (let [m (merge base-map m)]
      (->attrs opts m))))
 
+(defn attrs-prefix
+  "Implementation, do not use"
+  [s]
+  (if (= "" s) "" (str " " s)))
+
 (defn constant? [v]
   (not (or (seq? v) (symbol? v))))
 
@@ -128,16 +138,16 @@
             attrs (if ?attrs
                     (let [a (compile-attrs opts ?attrs)]
                       (if (string? a)
-                        (str " " a)
-                        a))
+                        (attrs-prefix a)
+                        `(attrs-prefix ~a)))
                     "")]
         (if unsafe?
           `(->Html (str ~(first children)))
           `(->Html (str ~@(if omit-tag?
                             nil
                             (if (string? attrs)
                               [(str "<" tag attrs ">")]
-                              ["<" tag " " attrs  ">"]))
+                              ["<" tag attrs ">"]))
                         ~@(map #(list (if xml?
                                         `xml
                                         `html) %) children)

test/borkdude/html_test.cljc

@@ -81,6 +81,44 @@
     "<input checked=\"true\"></input>"
     (xml [:input {:checked true}])
 
+    "<input>"
+    (html [:input {:disabled false}])
+
+    "<input>"
+    (html [:input {:disabled nil}])
+
+    "<input></input>"
+    (xml [:input {:disabled nil}])
+
+    "<input type=\"text\">"
+    (html [:input {:type "text" :disabled false}])
+
+    "<input type=\"text\">"
+    (let [d false]
+      (html [:input {:type "text" :disabled d}]))
+
+    "<button aria-expanded=\"true\"></button>"
+    (html [:button {:aria-expanded true}])
+
+    "<button aria-expanded=\"false\"></button>"
+    (html [:button {:aria-expanded false}])
+
+    "<button aria-expanded=\"false\"></button>"
+    (let [b false]
+      (html [:button {:aria-expanded b}]))
+
+    "<button aria-expanded=\"true\"></button>"
+    (xml [:button {:aria-expanded true}])
+
+    "<span></span>"
+    (html [:span {:aria-label nil}])
+
+    "<div role=\"checkbox\" aria-checked=\"mixed\"></div>"
+    (html [:div {:role "checkbox" :aria-checked "mixed"}])
+
+    "<div></div>"
+    (html [:div {:data-open false}])
+
     "<a href=\"http://dude\"></a>"
     (html [:a {:href (str "http://" "dude")}])
 
@@ -100,6 +138,9 @@
     "<div class=\"card\"></div>"
     (html [:div.card {}])
 
+    "<div></div>"
+    (html [:div {}])
+
     "<div class=\"card big\"></div>"
     (let [x "big"]
       (html [:div.card {:class x}]))