Custom phoenix form input helper

defmodule MyAppWeb.InputHelper do
  use Phoenix.HTML

  def input(form, field, opts \\ []) do
    type = Phoenix.HTML.Form.input_type(form, field)

    wrapper_classes = Keyword.get_values(opts, :wrapper_class) ++ ["row", "form-group"]
    inputs_classes = Keyword.get_values(opts, :input_class) ++ ["form-control"]

    if form.errors[field], do: inputs_classes = inputs_classes ++ ["form-control-danger"]
    if form.errors[field], do: wrapper_classes = wrapper_classes ++ ["has-danger"]

    wrapper_opts = [class: Enum.join(wrapper_classes, " ")]

    input_opts =
      [class: Enum.join(inputs_classes, " ")] ++
        Keyword.drop(opts, [:wrapper_class, :input_class])

    label = Keyword.get(opts, :label) || humanize(field)

    if input_validations(form, field) |> Keyword.get(:required) do
      label = label <> " *"
      input_opts = input_opts ++ [required: "required"]
    end

    content_tag :div, wrapper_opts do
      [
        content_tag :span, class: "col-sm-2" do
          label(form, field, label, class: "col-form-label float-sm-right")
        end,
        content_tag :div, class: "col-lg-6 col-md-10" do
          input = apply(Phoenix.HTML.Form, type, [form, field, input_opts])
          error = MyAppWeb.ErrorHelpers.error_tag(form, field)
          [input, error || ""]
        end
      ]
    end
  end
end

This is awesome! Thanks.

Looks like there might be one typo on L10. I believe the class should be form-control-danger not form-control-dange.

@aselder ah thanks.

I'm new to elixir so I can't fully understand how I'm supposed to properly fix the errors, but for each of the variables updated in the if statements, I get the following error -
variable "label" is unused (if the variable is not meant to be used, prefix it with an underscore) // same for inputs_classes and wrapper_classes.
So in case of errors, they don't get updated with form-control-danger class.

Edit - using Elixir 1.10.4 on windows 10