defmodule FrancisHtmx do
@moduledoc """
Provides a macro to render htmx content by loading htmx.js.
Also provides a sigil to render EEx content similar to ~H from Phoenix.LiveView
Usage:
```elixir
defmodule Example do
use Francis
import FrancisHtmx
htmx(fn _conn ->
assigns = %{}
~E\"\"\"
\"\"\"
end)
get("/colors", fn _ ->
new_color = 3 |> :crypto.strong_rand_bytes() |> Base.encode16() |> then(&"\#{&1}")
assigns = %{new_color: new_color}
~E\"\"\"
">
Color Swap Demo
\"\"\"
end)
end
```
In this scenario we are loading serving an HTML that has the htmx.js library loaded and serves the root content given by htmx/1
"""
defmacro __using__(opts) do
quote do
import FrancisHtmx
import unquote(__MODULE__), only: [htmx: 1, htmx: 2, sigil_E: 2]
checker = ~r/^(\d+\.)?(\d+\.)?(\*|\d+)$/
version = Application.compile_env(:francis_htmx, :version, "2")
version = Keyword.get(unquote(opts), :version, version)
title = Keyword.get(unquote(opts), :title, "")
head = Keyword.get(unquote(opts), :head, "")
if !Regex.match?(checker, version) do
raise "Invalid version format. Expected format is 'x.y.z' or 'x.y.*'. Got: '#{version}'"
end
Module.put_attribute(__MODULE__, :htmx_version, version)
Module.put_attribute(__MODULE__, :htmx_title, title)
Module.put_attribute(__MODULE__, :htmx_head, head)
Module.register_attribute(__MODULE__, :htmx_version, accumulate: false)
Module.register_attribute(__MODULE__, :htmx_title, accumulate: false)
Module.register_attribute(__MODULE__, :htmx_head, accumulate: false)
end
end
@doc """
Renders htmx content by loading htmx.js and rendering binary content.
"""
@spec htmx((Plug.Conn.t() -> binary())) :: Macro.t()
defmacro htmx(content) do
quote location: :keep do
get("/", fn conn ->
html(conn, """
#{@htmx_head}
#{@htmx_title}
#{unquote(content).(conn)}
""")
end)
end
end
@doc """
Renders htmx content by loading htmx.js and rendering binary content.
"""
@spec htmx((Plug.Conn.t() -> binary()), Keyword.t()) :: Macro.t()
defmacro htmx(content, opts) do
quote location: :keep do
get("/", fn conn ->
title = Keyword.get(unquote(opts), :title, @htmx_title)
head = Keyword.get(unquote(opts), :head, @htmx_head)
html(conn, """
#{head}
#{title}
#{unquote(content).(conn)}
""")
end)
end
end
@doc """
Provides a sigil to render EEx content similar to ~H from Phoenix.LiveView
If a variable named "assigns" doesn't exist, it will be set to an empty map.
"""
@spec sigil_E(String.t(), Keyword.t()) :: Macro.t()
defmacro sigil_E(content, _opts \\ []) do
if Macro.Env.has_var?(__CALLER__, {:assigns, nil}) do
quote location: :keep do
content =
EEx.eval_string(unquote(content), [assigns: var!(assigns)], engine: Phoenix.HTML.Engine)
content
|> Phoenix.HTML.html_escape()
|> Phoenix.HTML.safe_to_string()
end
else
quote location: :keep do
assigns = %{}
content =
EEx.eval_string(unquote(content), [assigns: assigns], engine: Phoenix.HTML.Engine)
content
|> Phoenix.HTML.html_escape()
|> Phoenix.HTML.safe_to_string()
end
end
end
end