# MobileNumberFormat

This library helps you parsing and validating mobile phone numbers.

It relies on the data available in Google's [libphonenumber](https://github.com/google/libphonenumber) library. Version `0.3.0` uses the data from version `v8.12.51` of `libphonenumber`.

### `parse/1`

```elixir
assert {:ok,
  %{
    iso_country_code: "BE",
    country_calling_code: "32",
    national_number: "455123456",
    trimmed_national_number_input: "455/12.34.56"
  }} =
    MobileNumberFormat.parse(%{
      country_calling_code: 32,
      national_number: "0455/12.34.56"
    })
```

The `parse/1` function receives a map that may contain any of these keys:
* `iso_country_code`
  For instance `"BE"`.

* `country_calling_code`
  For instance `"32"`, `"+32"` or `32`.
  Local international call prefixes are not supported (only the prefix `+` is supported).

* `national_number`
  For instance the Belgian national number `"455/12.34.56"`. National prefixes are supported `"0455/12.34.56"`.

* `international_number`
  For instance `"+32 455/12.34.56"`. A national prefix may be added in parentheses `"+32 (0)455/12.34.56"`.

In case the number is valid, the tuple `{:ok, data}` is returned where `data` is a map containing the 4 key/values mentioned above.

In case of error, the following atoms may be returned:

* `:invalid_iso_country_code`
* `:invalid_country_calling_code`
* `:invalid_number`
* `:insufficient_data`

### `valid_number?/1`

Same as `parse/1` but returns `true` or `false` whether the number is valid or not.

### `valid_country_calling_code?/1`

Checks whether the given country calling code is valid or not.

### `valid_iso_country_code?/1`

Checks whether the given ISO country code is valid or not.

### `formatting_data_per_territory/0`

Returns a list of all the formatting rules. Example of formatting rules (for Belgium):

```elixir
%{
  country_calling_code: "32",
  example: "470123456",
  iso_country_code: "BE",
  national_prefix: "0",
  possible_lengths: [9],
  regex: ~r/4[5-9]\d{7}/
}
```

## Example Ecto schema

Here is an example Ecto schema making use of `MobileNumberFormat` to validate mobile numbers. The examples supposes that the UI
contains 3 inputs:
* an input field to enter the country calling code
* an input field to enter the number
* a checkbox allowing to indicate whether the number is a mobile or not

```elixir
defmodule MyApp.MyContext.PhoneNumber do
  use Ecto.Schema
  import Ecto.Changeset

  @primary_key false

  embedded_schema do
    field :is_mobile, :boolean
    field :iso_country_code, :string
    field :country_calling_code, :string
    field :national_number, :string
    field :cleaned_national_number, :string
  end

  @fields ~w(is_mobile country_calling_code national_number)a

  def changeset(mobile, attrs) do
    mobile
    |> cast(attrs, @fields)
    |> validate_required(@fields)
    |> maybe_validate_and_clean()
  end

  defp maybe_validate_and_clean(changeset) do
    if Ecto.Changeset.fetch_field!(changeset, :is_mobile) do
      changed? =
        [:country_calling_code, :national_number]
        |> Enum.any?(&Map.has_key?(changeset.changes, &1))

      if changed? do
        validate_and_clean_mobile(changeset)
      else
        changeset
      end
    else
      changeset
    end
  end

  defp validate_and_clean_mobile(changeset) do
    parsed_data =
      MobileNumberFormat.parse(%{
        iso_country_code: fetch_field!(changeset, :iso_country_code),
        country_calling_code: fetch_field!(changeset, :country_calling_code),
        national_number: fetch_field!(changeset, :national_number)
      })

    case parsed_data do
      :invalid_iso_country_code ->
        add_error(changeset, :invalid_iso_country_code, "country is not valid")

      :invalid_country_calling_code ->
        add_error(changeset, :invalid_country_calling_code, "country calling code is not valid")

      :invalid_number ->
        add_error(changeset, :invalid_number, "mobile number is not valid")

      :insufficient_data ->
        raise "unexpected error"

      parsed_data ->
        {:ok, %{
          iso_country_code: iso_country_code,
          country_calling_code: country_calling_code,
          national_number: cleaned_national_number
        }} = parsed_data

        change(changeset, %{
          iso_country_code: iso_country_code,
          country_calling_code: country_calling_code,
          cleaned_national_number: cleaned_national_number
        })
    end
  end
end
```

## Installation

Add `mobile_number_format` for Elixir as a dependency in your `mix.exs` file:

```elixir
def deps do
  [
    {:mobile_number_format, "~> 0.3.0"}
  ]
end
```

## HexDocs

HexDocs documentation can be found at [https://hexdocs.pm/mobile_number_format](https://hexdocs.pm/mobile_number_format).