From 06cbdd80ff997a2190419c9f9a29dde10657420e Mon Sep 17 00:00:00 2001
From: Mitchell Hanberg <mitch@mitchellhanberg.com>
Date: Fri, 10 May 2019 15:06:03 -0400
Subject: [PATCH] form_for and text_input macros

---
 lib/dsl/html.ex        | 58 +++++++++++++++++++++++++++++++++++++++---
 mix.exs                |  7 +++--
 test/dsl/html_test.exs | 51 +++++++++++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+), 6 deletions(-)

diff --git a/lib/dsl/html.ex b/lib/dsl/html.ex
index f4ab181..296035f 100644
--- a/lib/dsl/html.ex
+++ b/lib/dsl/html.ex
@@ -25,7 +25,9 @@ defmodule Dsl.Html do
     area br col embed hr img input keygen param source track wbr
   ]a
 
+  @doc false
   def nonvoid_elements, do: @nonvoid_elements
+  @doc false
   def void_elements, do: @void_elements
 
   @doc """
@@ -55,6 +57,7 @@ defmodule Dsl.Html do
     quote do
       import Kernel, except: [div: 2]
       import HTML.Link, except: [link: 1, link: 2]
+      import HTML.Form, only: []
 
       {:ok, var!(buff, Dsl.Html)} = Utils.start_buffer([])
 
@@ -200,12 +203,59 @@ defmodule Dsl.Html do
     end
   end
 
-  end
-
-
-
+  @doc """
+  Generates an empty form tag.
 
+  See `Dsl.Html.form_for/4` for more details
+  """
+  defmacro form_for(form_data, action) do
+    quote do
+      form_for(unquote_splicing([form_data, action]), [])
     end
   end
 
+  @doc """
+  Generates a form tag with a form builder and a block.
+
+  The form builder will be available inside the block through the `form` variable.
+
+  This is a wrapper around the `Phoenix.HTML.Form.form_for/4` function and accepts all of the same options.
+
+  ## Example
+
+  ```
+  htm do
+    form_for @conn, Routes.some_path(@conn, :create) do
+      text_input form, :name
+    end
+  end
+
+  # {:safe,
+  #   "<form accept-charset=\"UTF-8\" action=\"/\" method=\"post\">
+  #      <input name=\"_csrf_token\" type=\"hidden\" value=\"AS5qfX1gcns6eU56BlQgBlwCDgMlNgAAiJ0MR91Kh3v3bbCS5SKjuw==\">
+  #      <input name=\"_utf8\" type=\"hidden\" value=\"✓\">
+  #      <input id=\"name\" name=\"name\" type=\"text\">
+  #    </form>"}
+  ```
+  """
+  defmacro form_for(form_data, action, opts \\ [], block) do
+    quote do
+      var!(form) = HTML.Form.form_for(unquote_splicing([form_data, action, opts]))
+
+      Utils.put_buffer(var!(buff, Dsl.Html), var!(form) |> HTML.Safe.to_iodata())
+      _ = unquote(block)
+      Utils.put_buffer(var!(buff, Dsl.Html), "</form>")
+    end
+  end
+
+  @doc """
+  Please see `Phoenix.HTML.Form.text_input/3` for details.
+  """
+  defmacro text_input(form, field, opts \\ []) do
+    quote do
+      {:safe, input} = HTML.Form.text_input(unquote_splicing([form, field, opts]))
+
+      Utils.put_buffer(var!(buff, Dsl.Html), input)
+    end
+  end
 end
diff --git a/mix.exs b/mix.exs
index e3402fa..fc8f93f 100644
--- a/mix.exs
+++ b/mix.exs
@@ -13,7 +13,10 @@ defmodule Dsl.MixProject do
       source_url: "https://github.com/mhanberg/cogent",
       docs: [
         main: "Dsl",
-        extras: ["README.md"]
+        extras: ["README.md"],
+        deps: [
+          phoenix_html: "https://hexdocs.pm/phoenix_html/"
+        ]
       ],
       dialyzer: [plt_add_apps: [:mix, :phoenix, :html_sanitize_ex]]
     ]
@@ -35,7 +38,7 @@ defmodule Dsl.MixProject do
     [
       {:phoenix_html, "~> 2.13"},
       {:ex_doc, "~> 0.0", only: [:dev], runtime: false},
-      {:html_sanitize_ex, "~> 1.3", only: [:dev], runtime: false},
+      {:html_sanitize_ex, "~> 1.3", only: [:dev, :test], runtime: false},
       {:phoenix, "~> 1.4", optional: true},
       {:plug, "~> 1.8", optional: true},
       {:dialyxir, "~> 1.0.0-rc.6", only: [:dev], runtime: false}
diff --git a/test/dsl/html_test.exs b/test/dsl/html_test.exs
index 79e3a0a..58016c8 100644
--- a/test/dsl/html_test.exs
+++ b/test/dsl/html_test.exs
@@ -399,4 +399,55 @@ defmodule Dsl.HtmlTest do
       assert result == ~s{<div class="hi world"></div>}
     end
   end
+
+  describe "form_for" do
+    test "returns a form tag" do
+      conn = %Plug.Conn{}
+      action = "/"
+
+      {:safe, result} =
+        htm do
+          form_for(conn, action, [])
+        end
+
+      assert result =~ ~s{<form}
+      assert result =~ ~s{</form>}
+    end
+
+    test "can take a block" do
+      conn = %Plug.Conn{}
+      action = "/"
+      opts = []
+
+      {:safe, result} =
+        htm do
+          form_for conn, action, opts do
+            div()
+          end
+        end
+
+      assert result =~ ~s{<form}
+      assert result =~ ~s{<div></div>}
+      assert result =~ ~s{</form>}
+    end
+
+    test "can take a block that references the form" do
+      conn = %Plug.Conn{}
+      action = "/"
+      opts = []
+
+      {:safe, result} =
+        htm do
+          form_for conn, action, opts do
+            text_input(form, :bob)
+          end
+        end
+
+      assert result =~ ~s{<form}
+      assert result =~ ~s{<input}
+      assert result =~ ~s{type="text"}
+      assert result =~ ~s{name="bob"}
+      assert result =~ ~s{</form>}
+    end
+  end
 end