Ecto.Changeset.validate_length/3 error message: replacing %{count}

Questions / Help
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1

When using Ecto.Changeset.validate_length/3, the error message when the string is less than the minimum characters is “should be at least %{count} character(s)”.

What is the simplest way to replace %{count} with the actual minimum number of characters when the message is passed back as an error?

Also, just curious, is there a reason the function doesn’t insert the count for you?

Thanks!
Axel

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2

I just found Ecto.Changeset.traverse_errors/2 uses this exact situation as the example.

error message:

{"should be at least %{count} characters", [count: 3, validation: :length, min: 3]}

function:

traverse_errors(changeset, fn {msg, opts} ->
  Enum.reduce(opts, msg, fn {key, value}, acc ->
    String.replace(acc, "%{#{key}}", to_string(value))
  end)
end)
%{title: ["should be at least 3 characters"]}
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