Fill in README

README.md

@@ -1,6 +1,10 @@
 # Dsl
 
-**TODO: Add description**
+[![Build Status](https://travis-ci.com/mhanberg/dsl.svg?branch=master)](https://travis-ci.com/mhanberg/dsl)
+
+Dsl is a DSL for writing HTML using Elixir.
+
+You're probably here because you want to use Dsl to write Phoenix templates, which is why Dsl includes a [Phoenix template engine](#phoenix-templates) and Dsl-compatible [Phoenix form helpers](#phoenixhtml).
 
 ## Installation
 
@@ -15,7 +19,127 @@ def deps do
 end
 ```
 
-Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
-and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
-be found at [https://hexdocs.pm/dsl](https://hexdocs.pm/dsl).
+## Usage
 
+```elixir
+use Dsl
+
+htm do
+  h2 "todos"
+
+  ul class: "list" do
+    for item <- @items do
+      li class: "item" do
+        div class: "checkbox" do
+          div class: "bullet hidden"
+        end
+
+        div item
+      end
+    end
+  end
+
+  script """
+  function toggleCheck({currentTarget}) {
+    currentTarget.children[0].children[0].classList.toggle("hidden");
+  }
+
+  let items = document.querySelectorAll("li");
+
+  Array.from(items).forEach(checkbox => checkbox.addEventListener("click", toggleCheck));
+  """
+end
+```
+
+### Components
+
+Dsl provides an API for creating custom components that act as custom HTML elements.
+
+These components can be given `props` that are available inside the component definition as module attributes. The contents of a components `do` block are available as a special `@children` attribute.
+
+```elixir
+defcomponent :flex do
+  div id: @id, class: "flex" do
+    @children
+  end
+end
+
+htm do
+  flex id: "my-flex" do
+    div "Item 1"
+    div "Item 2"
+    div "Item 3"
+  end
+end
+```
+
+### Phoenix.HTML
+
+Dsl provides macros for working with the helpers provided by the [Phoenix.HTML](https://www.github.com/phoenixframework/phoenix_html) package.
+
+Most of the macros are purely wrappers, while the semantics of some are changed to work with Dsl.
+
+```elixir
+htm do
+  form_for @conn, Routes.some_path(@conn, :create) do
+    text_input form, :name
+  end
+end
+```
+
+### Phoenix templates
+
+Add the templating engine to your Phoenix configuration.
+
+```elixir
+# config.exs
+config :phoenix, :template_engines, exs: Dsl.Engine
+
+# your_app_web.ex
+def view do
+  quote do
+    # ...
+    use Dsl # Replaces the call to import Phoenix.HTML
+  end
+end
+```
+
+```elixir
+# app.html.exs
+html lang: "en" do
+  head do
+    meta charset: "utf-8"
+    meta http_equiv: "X-UA-Compatible", content: "IE=edge"
+    meta name: "viewport", content: "width=device-width, initial-scale=1.0"
+    title "YourApp · Phoenix Framework"
+
+    link rel: "stylesheet", href: Routes.static_path(@conn, "/css/app.css")
+  end
+
+  body do
+    header do
+      section class: "container" do
+        nav role: "navigation" do
+          ul do
+            li do: a("Get Started", href: "https://hexdocs.pm/phoenix/overview.html")
+          end
+        end
+
+        a href: "http://phoenixframework.org/", class: "phx-logo" do
+          img src: Routes.static_path(@conn, "/images/phoenix.png"),
+              alt: "Phoenix Framework Logo"
+        end
+      end
+    end
+
+    main role: "main", class: "container" do
+      p get_flash(@conn, :info), class: "alert alert-info", role: "alert"
+      p get_flash(@conn, :error), class: "alert alert-danger", role: "alert"
+
+      partial render(@view_module, @view_template, assigns)
+    end
+
+    script type: "text/javascript", src: Routes.static_path(@conn, "/js/app.js")
+  end
+end
+```

lib/dsl/engine.ex

@@ -9,6 +9,14 @@ defmodule Dsl.Engine do
   ```elixir
   # config.exs
   config :phoenix, :template_engines, exs: Dsl.Engine
+
+  # your_app_web.ex
+  def view do
+    quote do
+      # ...
+      use Dsl # Replaces the call to import Phoenix.HTML
+    end
+  end
   ```
 
   ## Usage