# `AccessGrid.Utils`
[🔗](https://github.com/Access-Grid/accessgrid-ex/blob/main/lib/access_grid/utils.ex#L1)

Utility helpers for composing API request params.

These functions are intentionally not invoked automatically by the Console /
AccessPasses functions — they're building blocks. Callers compose the params they
want and pass them through.

# `base64_file`

```elixir
@spec base64_file(Path.t()) :: {:ok, String.t()} | {:error, File.posix()}
```

Reads `path` and returns its contents Base64-encoded.

Pairs with image-accepting endpoints (`Console.create_template/2`,
`Console.update_template/3`, `Console.create_landing_page/2`,
`Console.update_landing_page/3`, `AccessPasses.issue/2`, `AccessPasses.update/3`) —
Rails decodes the base64 string server-side and attaches the resulting image.

Returns `{:ok, encoded}` on success or `{:error, reason}` on failure, where
`reason` is the posix atom from `File.read/1` (`:enoent`, `:eacces`, etc.).

## Examples

    {:ok, b64} = AccessGrid.Utils.base64_file("badge.png")

    AccessGrid.Console.create_template(
      %{
        name: "Employee Badge",
        platform: "apple",
        background: b64
      },
      client: client
    )

# `base64_file!`

```elixir
@spec base64_file!(Path.t()) :: String.t()
```

Same as `base64_file/1` but raises `File.Error` on failure.

Use when the file is known to exist and an unrecoverable error is appropriate.

## Examples

    b64 = AccessGrid.Utils.base64_file!("badge.png")

---

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