# `CardBrand`

A card scheme: `visa`, `mastercard`, `american_express` and so on.

Use it to show which logo goes beside a card, or to accept only certain schemes. `money.mask` tells it from a card's number, so you rarely set it yourself.

## Shape

One of these 8 values:

`CardBrand.american_express`, `CardBrand.diners_club`, `CardBrand.discover`, `CardBrand.jcb`, `CardBrand.maestro`, `CardBrand.mastercard`, `CardBrand.unionpay`, `CardBrand.visa`.

## Example

```jadpo
CardBrand.visa
```

`text.parse(raw, as: CardBrand)` reads one from text that comes from outside. Text that isn't one at all fails `malformed`, such as `americanexpress`, `Visa Electron` or `master_card`.

## Good to know

- `==` tells you whether two are the same. `<` and `list.sort_by` don't take it.

## In JSON

A string, in a request, a response or `json.write`:

```json
"american_express"
"mastercard"
"visa"
```

## Details

<details>
<summary>Text form, storage, how it is shown, and operations</summary>

`CardBrand` is in the group Money and banking, and has been in Jadpo since 0.1.0.

### Text form

`text.from` writes one standard text form, the same form `text.parse` reads back: `american_express`, `mastercard` and `visa`.

### How it is stored

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

### How it is shown to people

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

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `american_express` | `American Express` |
| `mastercard` | `Mastercard` |
| `visa` | `Visa` |

### Operations

It also takes `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. [How every standard type behaves](/docs/every-standard-type-meets-one-contract.md) says how they work.

</details>