Tutorial

Quicktip: Customize look of form validation in Phoenix

This post was updated 01 May - 2020

formsphoenix
When submitting a form in a Phoenix and get validation errors, you are displayed with a little validation error text. However, you probably want to customize how that error message is displayed. For example, what I don't like is that it just say

"`can't be blank`"

And also, the class that is attached is not compatible with Tailwind or Bootstrap. So, for my use case I want it to have both the field name attached and some Tailwind classes. 

To accomplish that, you can do that in the file: `lib/tutorial_web/views/error_helpers.ex`

So, out of the box, the code looks something like this:
  def error_tag(form, field) do
    Enum.map(Keyword.get_values(form.errors, field), fn error ->
      content_tag(:span, translate_error(error), class: "help-block")
    end)
  end

And change it to something like this:

  def error_tag(form, field) do
    Enum.map(Keyword.get_values(form.errors, field), fn error ->
      field = field |> Atom.to_string() |> String.capitalize()
      content_tag(:span, "#{field} #{translate_error(error)}", class: "block mt-1 text-sm text-red-700")
    end)
  end

### END RESULT
![](https://res.cloudinary.com/dwvh1fhcg/image/upload/w_650,c_scale/v1579678301/tutorials/quicktip_1.png)

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