linkify/lib/auto_linker/builder.ex
2017-03-29 16:27:13 -04:00

59 lines
1.7 KiB
Elixir

defmodule AutoLinker.Builder do
@moduledoc """
Module for building the auto generated link.
"""
@doc """
Create a link.
"""
def create_link(url, opts) do
[]
|> build_attrs(url, opts, :rel)
|> build_attrs(url, opts, :target)
|> build_attrs(url, opts, :class)
|> build_attrs(url, opts, :scheme)
|> format_url(url, opts)
end
defp build_attrs(attrs, _, opts, :rel) do
if rel = Map.get(opts, :rel, "noopener noreferrer"),
do: [{:rel, rel} | attrs], else: attrs
end
defp build_attrs(attrs, _, opts, :target) do
if Map.get(opts, :new_window, true),
do: [{:target, :_blank} | attrs], else: attrs
end
defp build_attrs(attrs, _, opts, :class) do
if cls = Map.get(opts, :class, "auto-linker"),
do: [{:class, cls} | attrs], else: attrs
end
defp build_attrs(attrs, url, _opts, :scheme) do
if String.starts_with?(url, ["http://", "https://"]),
do: [{:href, url} | attrs], else: [{:href, "http://" <> url} | attrs]
end
defp format_url(attrs, url, opts) do
url =
url
|> strip_prefix(Map.get(opts, :strip_prefix, true))
|> truncate(Map.get(opts, :truncate, false))
attrs =
attrs
|> Enum.map(fn {key, value} -> ~s(#{key}='#{value}') end)
|> Enum.join(" ")
"<a #{attrs}>" <> url <> "</a>"
end
defp truncate(url, false), do: url
defp truncate(url, len) when len < 3, do: url
defp truncate(url, len) do
if String.length(url) > len, do: String.slice(url, 0, len - 2) <> "..", else: url
end
defp strip_prefix(url, true) do
url
|> String.replace(~r/^https?:\/\//, "")
|> String.replace(~r/^www\./, "")
end
defp strip_prefix(url, _), do: url
end