acceptsConfig

Kind: Interface

Source: src/helper/accepts/accepts.ts

Part of: Helper

acceptsConfig defines the configuration required for Accept header handling. It stores the parsed AcceptHeader, a list of supported content types, and the fallback content type returned when no supported match is found.

Properties

Diagram

mermaid
graph LR
  Config[acceptsConfig]
  Header[header: AcceptHeader]
  Supports[supports: string[]]
  Default[default: string]

  Config --> Header
  Config --> Supports
  Config --> Default

Usage

ts
import type { acceptsConfig } from './helper/accepts/accepts';

const config: acceptsConfig = {
  header: requestAcceptHeader,
  supports: ['application/json', 'text/html'],
  default: 'application/json',
};

function selectContentType(config: acceptsConfig): string {
  return config.default;
}

AI Coding Instructions

• Pass a parsed AcceptHeader value through header; do not replace it with a raw header string.
• Keep supports limited to content types the calling code can return.
• Set default to a value that also exists in supports.
• Use acceptsConfig when passing Accept negotiation settings between request handling code and content-type selection logic.

How it works

acceptsConfig is an exported TypeScript interface that describes the required configuration shared by the accepts helper and its matching functions. It has three required fields: header, supports, and default. [src/helper/accepts/accepts.ts:11-15]

• header selects the request header that accepts reads. Its type is AcceptHeader, limited to 'Accept', 'Accept-Charset', 'Accept-Encoding', 'Accept-Language', 'Accept-Patch', 'Accept-Post', or 'Accept-Ranges'. [src/helper/accepts/accepts.ts:12] [src/utils/headers.ts:345-352]
• supports is a string[] of candidate values for matching. [src/helper/accepts/accepts.ts:13]
• default is the string returned when the selected header is absent or when the default matcher finds no supported accepted type. [src/helper/accepts/accepts.ts:14] [src/helper/accepts/accepts.ts:21-25] [src/helper/accepts/accepts.ts:40-48]

acceptsOptions extends this interface with an optional match callback. That callback receives parsed accept entries and the same acceptsConfig object, and returns a string. [src/helper/accepts/accepts.ts:17-19] When no callback is supplied, accepts uses defaultMatch. [src/helper/accepts/accepts.ts:45-48]

The default matcher sorts parsed entries by descending q value, selects the first entry whose type occurs in supports, and returns that type; otherwise it returns default. [src/helper/accepts/accepts.ts:21-25] The matcher calls .sort() on its accepts argument. [src/helper/accepts/accepts.ts:23]

accepts reads c.req.header(options.header). If that value is falsy, it returns options.default; otherwise, it parses the header and invokes either options.match or defaultMatch with the parsed entries and configuration. [src/helper/accepts/accepts.ts:40-48]

No runtime validation or explicit error handling for the three configuration fields appears in this file. [src/helper/accepts/accepts.ts:11-19]