# `Money.SQL.JSON`
[🔗](https://github.com/ex-money/money_sql/blob/v2.1.0/lib/money/sql/json.ex#L1)

A Postgrex `:json_library` adapter over the Erlang `:json` module.

`Money.Ecto.Map.Type` stores a money amount in a `jsonb` column, so
Postgrex needs a JSON library to encode and decode it. Postgrex calls
`encode_to_iodata!/1` and `decode!/1`, which the Erlang `:json` module
does not provide under those names; this module supplies them.

Configure it in your application:

    config :postgrex, :json_library, Money.SQL.JSON

`:json` is built into OTP 27 and later. On OTP 26 add
[json_polyfill](https://hex.pm/packages/json_polyfill), which provides
it:

    {:json_polyfill, "~> 0.2 or ~> 1.0"}

Postgrex reads this setting at compile time, so after changing it run
`mix deps.compile postgrex --force` once.

Any module exposing `encode_to_iodata!/1` and `decode!/1` works here —
Elixir 1.18's built-in `JSON` module does, as does `Jason`. This module
exists so that the same configuration works on every Elixir and OTP
version this library supports.

# `decoded`

```elixir
@type decoded() :: :json.decode_value()
```

A term decoded from JSON, as defined by the Erlang `:json` module.

# `encodable`

```elixir
@type encodable() :: :json.encode_value()
```

A term that can be encoded as JSON, as defined by the Erlang `:json`
module.

# `decode!`

```elixir
@spec decode!(iodata()) :: decoded()
```

Decodes JSON into a term.

### Arguments

* `json` is a JSON string or iodata.

### Returns

* The decoded term.

### Examples

    iex> Money.SQL.JSON.decode!(~s({"currency":"USD"}))
    %{"currency" => "USD"}

# `encode_to_iodata!`

```elixir
@spec encode_to_iodata!(encodable()) :: iodata()
```

Encodes a term as JSON iodata.

### Arguments

* `term` is any term the Erlang `:json` module can encode.

### Returns

* The encoded JSON as iodata.

### Examples

    iex> Money.SQL.JSON.encode_to_iodata!(%{"currency" => "USD"}) |> IO.iodata_to_binary()
    "{\"currency\":\"USD\"}"

---

*Consult [api-reference.md](api-reference.md) for complete listing*