# `TerminusDB.Schema`
[🔗](https://github.com/thanos/terminusdb-client-elixir/blob/v0.3.3/lib/terminus_db/schema.ex#L1)

Schema frame API for TerminusDB.

Wraps the `/api/schema` endpoint, which returns the class frame for a class or
all classes for a database's schema. A "frame" is a JSON-LD description of a
schema class: its properties, types, key strategy, and documentation.

All functions require a `TerminusDB.Config` scoped to a database (via
`TerminusDB.Config.with_database/2`).

## Quick start

    config =
      TerminusDB.Config.new(endpoint: "http://localhost:6363")
      |> TerminusDB.Config.with_database("mydb")

    # Get the frame for a specific class
    {:ok, frame} = TerminusDB.Schema.frame(config, "Person")
    # => %{"@type" => "Class", "name" => "xsd:string", ...}

    # Get all class frames
    {:ok, all} = TerminusDB.Schema.all(config)
    # => %{"Person" => %{"@type" => "Class", ...}, "Room" => %{...}}

# `frame_opt`

```elixir
@type frame_opt() ::
  {:compress_ids, boolean()}
  | {:expand_abstract, boolean()}
  | {:organization, String.t()}
```

# `all`

```elixir
@spec all(TerminusDB.Config.t(), [frame_opt()]) ::
  {:ok, map()} | {:error, TerminusDB.Error.t()}
```

Returns all class frames for the database's schema.

Equivalent to `frame(config, nil, opts)`.

## Examples

    iex> config = TerminusDB.Config.new(
    ...>   endpoint: "http://localhost:6363",
    ...>   adapter: fn req ->
    ...>     {req, Req.Response.new(status: 200, body: %{"@context" => %{"@type" => "Context"}, "Person" => %{"@type" => "Class"}})}
    ...>   end
    ...> ) |> TerminusDB.Config.with_database("mydb")
    iex> {:ok, all} = TerminusDB.Schema.all(config)
    iex> Map.keys(all)
    ["Person"]

# `all!`

```elixir
@spec all!(TerminusDB.Config.t(), [frame_opt()]) :: map()
```

Returns all class frames, or raises `TerminusDB.Error`.

## Examples

    iex> config = TerminusDB.Config.new(
    ...>   endpoint: "http://localhost:6363",
    ...>   adapter: fn req -> {req, Req.Response.new(status: 200, body: %{"Person" => %{"@type" => "Class"}})} end
    ...> ) |> TerminusDB.Config.with_database("mydb")
    iex> TerminusDB.Schema.all!(config)
    %{"Person" => %{"@type" => "Class"}}

# `frame`

```elixir
@spec frame(TerminusDB.Config.t(), String.t() | nil, [frame_opt()]) ::
  {:ok, map()} | {:error, TerminusDB.Error.t()}
```

Returns the class frame for a specific class `class_name`, or all class frames
if `class_name` is `nil`.

## Options

- `:compress_ids` — compress the URLs returned using prefixes (default `true`).
- `:expand_abstract` — expand abstract classes into lists of concrete classes
  in frame options (default `true`).
- `:organization` — overrides `config.organization`.

## Examples

Get the frame for a specific class:

    iex> config = TerminusDB.Config.new(
    ...>   endpoint: "http://localhost:6363",
    ...>   adapter: fn req ->
    ...>     {req, Req.Response.new(status: 200, body: %{"@type" => "Class", "name" => "xsd:string"})}
    ...>   end
    ...> ) |> TerminusDB.Config.with_database("mydb")
    iex> {:ok, frame} = TerminusDB.Schema.frame(config, "Person")
    iex> frame["name"]
    "xsd:string"

Get all class frames (pass `nil` or omit `class_name`):

    iex> config = TerminusDB.Config.new(
    ...>   endpoint: "http://localhost:6363",
    ...>   adapter: fn req ->
    ...>     {req, Req.Response.new(status: 200, body: %{"Person" => %{"@type" => "Class"}, "Room" => %{"@type" => "Class"}})}
    ...>   end
    ...> ) |> TerminusDB.Config.with_database("mydb")
    iex> {:ok, all} = TerminusDB.Schema.frame(config)
    iex> Map.keys(all) |> Enum.sort()
    ["Person", "Room"]

# `frame!`

```elixir
@spec frame!(TerminusDB.Config.t(), String.t() | nil, [frame_opt()]) :: map()
```

Returns the class frame, or raises `TerminusDB.Error`.

## Examples

    iex> config = TerminusDB.Config.new(
    ...>   endpoint: "http://localhost:6363",
    ...>   adapter: fn req -> {req, Req.Response.new(status: 200, body: %{"@type" => "Class", "name" => "xsd:string"})} end
    ...> ) |> TerminusDB.Config.with_database("mydb")
    iex> TerminusDB.Schema.frame!(config, "Person")
    %{"@type" => "Class", "name" => "xsd:string"}

---

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