Conditional Validation in Ecto for OR - 1 of 2 fields is required

Question

How can I do conditional validation for OR logic, where we check to see if 1 of the 2 values is present or both values are present.

So, for example, if I want to check t

Answer 1

How about:

  def validate_required_inclusion(changeset, fields,  options \\ []) do
    if Enum.any?(fields, fn(field) -> get_field(changeset, field) end), 
      do: changeset,
      else: add_error(changeset, hd(fields), "One of these fields must be present: #{inspect fields}")
  end

get_field gives you fields accepted by the change set, both changed (cast) and non-changed, and Enum.any? will ensure that at least one of the field is in there.