# `PhoneExtension`

An internal extension dialled after a phone number: up to 20 digits. Personal data.

[People and contact](types.md#people-and-contact); not ordered; personal data (contact); since Jadpo 0.1.0.

## Make one

Build one from its text, `PhoneExtension("1")`, which checks it: text that isn't one breaks `format`.

`text.parse(raw, as: PhoneExtension)` reads one from its text; text that isn't one at all fails `malformed`, such as `""`, `x2047` or `20 47`.

## Text, JSON and storage

`text.from` writes its canonical text, the one form `text.parse` reads back. JSON sends its canonical text as a string.

| Text | JSON |
|---|---|
| `1` | `"1"` |
| `2047` | `"2047"` |

It is stored in one column named for the field, of type `text`. `2047` is stored as `'2047'`.

## Shown to people

`text.format(value, locale:)` shows it to people in their locale.

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `1` | `1` |
| `2047` | `2047` |

## Operations

It has the contract's own operations: `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. It isn't ordered, so `<` and sorting don't take it. [Every standard type meets one contract](../topics/every-standard-type-meets-one-contract.md) says how they work.