Document void and nonvoid element macros

The mix task will fetch the element documentation from MDN for each
element and include that in the documentation.

The main documentation for these macros will be in the moduledoc

lib/dsl/html.ex

@@ -24,6 +24,9 @@ defmodule Dsl.Html do
     area br col embed hr img input keygen param source track wbr
   ]a
 
+  def nonvoid_elements, do: @nonvoid_elements
+  def void_elements, do: @void_elements
+
   @doc """
   Creates a markup context.
 
@@ -65,6 +68,9 @@ defmodule Dsl.Html do
   end
 
   for el <- @nonvoid_elements do
+    @doc """
+    #{File.read!("./tmp/docs/#{el}.txt")}
+    """
     defmacro unquote(el)() do
       el = unquote(el)
 
@@ -74,26 +80,28 @@ defmodule Dsl.Html do
       end
     end
 
-    defmacro unquote(el)([{:do, inner} | attrs]) do
+    @doc false
+    defmacro unquote(el)([{:do, inner}] = _attrs_or_content_or_block) do
       el = unquote(el)
 
       quote do
-        put_open_tag(var!(buff, Dsl.Html), unquote(el), unquote(attrs))
+        put_open_tag(var!(buff, Dsl.Html), unquote(el), [])
         _ = unquote(inner)
         put_close_tag(var!(buff, Dsl.Html), unquote(el))
       end
     end
 
-    defmacro unquote(el)(attrs_or_content) do
+    defmacro unquote(el)(attrs_or_content_or_block) do
       el = unquote(el)
 
       quote do
-        put_open_tag(var!(buff, Dsl.Html), unquote(el), unquote(attrs_or_content))
+        put_open_tag(var!(buff, Dsl.Html), unquote(el), unquote(attrs_or_content_or_block))
         put_close_tag(var!(buff, Dsl.Html), unquote(el))
       end
     end
 
-    defmacro unquote(el)(attrs, [{:do, inner}]) do
+    @doc false
+    defmacro unquote(el)(attrs, [{:do, inner}] = _block) do
       el = unquote(el)
 
       quote do
@@ -130,6 +138,10 @@ defmodule Dsl.Html do
   end
 
   for el <- @void_elements do
+    @doc """
+    #{File.read!("./tmp/docs/#{el}.txt")}
+    """
+
     defmacro unquote(el)(attrs \\ []) do
       el = unquote(el)
 

lib/mix/tasks/update_mdn_docs.ex

@@ -0,0 +1,29 @@
+defmodule Mix.Tasks.UpdateMdnDocs do
+  use Mix.Task
+
+  @baseurl "https://developer.mozilla.org/en-US/docs/Web/HTML/Element/"
+  @params "?summary&raw"
+
+  @shortdoc "Update the MDN documentation"
+  def run(_) do
+    (Dsl.Html.nonvoid_elements() ++ Dsl.Html.void_elements())
+    |> Enum.each(fn el ->
+      el = to_string(el)
+
+      page =
+        if Enum.any?(["h1", "h2", "h3", "h4", "h5", "h6"], & &1 == el) do
+          "Heading_Elements"
+        else
+          el
+        end
+
+      {doc, 0} = System.cmd("curl", [@baseurl <> page <> @params])
+      File.mkdir_p!("./tmp/docs/")
+
+      path = "./tmp/docs/" <> el <> ".txt"
+      doc = HtmlSanitizeEx.strip_tags(doc)
+
+      File.write!(path, doc)
+    end)
+  end
+end