# detectors

**Kind:** Constant

**Source:** [`src/middleware/language/language.ts`](https://github.com/honojs/hono/blob/main/src/middleware/language/language.ts#L186)

**Part of:** [Middleware](subsystem-src-middleware)

Collection of all language detection strategies

`detectors` is the collection of language detection strategies used by the language middleware. The middleware checks these strategies to determine the language for an incoming request and apply the selected language to downstream processing.

## Definition

```ts
{
  querystring: detectFromQuery,
  cookie: detectFromCookie,
  header: detectFromHeader,
  path: detectFromPath,
} as const
```

## Value

```ts
{
  querystring: detectFromQuery,
  cookie: detectFromCookie,
  header: detectFromHeader,
  path: detectFromPath,
} as const
```

## Diagram

```mermaid
graph LR
  Request[Incoming request] --> Middleware[Language middleware]
  Middleware --> Detectors[detectors]
  Detectors --> Strategy[Language detection strategy]
  Strategy --> Language[Detected language]
  Language --> Context[Request language context]
```

## Usage

```ts
import { detectors } from './middleware/language/language';

// Inspect the detection strategies registered with the language middleware.
for (const detector of detectors) {
  console.log(detector);
}
```

## AI Coding Instructions

- Keep each entry in `detectors` compatible with the language middleware's expected detector contract.
- Add new language detection strategies to this collection so the middleware can evaluate them.
- Preserve detector ordering when precedence affects which language source is selected.
- Update related middleware tests when adding, removing, or changing a detector.
- Avoid placing request-specific state in the shared `detectors` collection.