HttpParameter

Package: @opra/common

HttpParameter represents a single declared parameter on an HttpController or HttpOperation. Parameters can be located in the query string, URL path, request headers, or cookies. The adapter decodes and validates each parameter against its declared type before calling the operation handler.

---

Inheritance

DocumentElement
└── Value
    └── HttpParameter

Value contributes name, type, description, isArray, and examples.

---

Properties

Properties inherited from Value:

Property	Type	Description
name	string | RegExp	Parameter name, or a RegExp for pattern-based matching.
type	DataType | undefined	Declared type used for decoding and validation.
description	string | undefined	Human-readable description.
isArray	boolean | undefined	Whether the parameter holds an array of values.
examples	any[] | Record<string, any> | undefined	Example values.

Properties on HttpParameter:

Property	Type	Description
location	'query' | 'path' | 'header' | 'cookie'	Where the parameter appears in the HTTP request.
required	boolean | undefined	Whether the parameter must be present. Always true for 'path' parameters.
default	any	Default value applied when the parameter is absent.
arraySeparator	string | undefined	Separator used to split a comma-separated string into an array (e.g. ',').
keyParam	boolean | undefined	Marks this parameter as the entity key parameter.
deprecated	boolean | string | undefined	Marks the parameter as deprecated.
parser	((v: any) => any) | undefined	Custom parsing function applied after type decoding.

---

Methods

generateCodec(codec, options?)

Compiles a validator for this parameter's type. If a default value is declared, wraps the validator so the default is applied when the parameter is absent.

generateCodec(
  codec: 'encode' | 'decode',
  options?: DataType.GenerateCodecOptions
): Validator

---

toJSON(options?)

Returns an OpraSchema.HttpParameter plain object for schema export.

toJSON(options?: ApiDocument.ExportOptions): OpraSchema.HttpParameter

---

Accessing parameters at runtime

Parameters are not accessed directly via HttpParameter — the adapter decodes them before the handler is called. Inside a handler use HttpContext:

async get(ctx: HttpContext) {
  const id     = ctx.pathParams.customerId;   // path parameter
  const limit  = ctx.queryParams.limit;        // query parameter
  const token  = ctx.headers['authorization']; // header
}

To inspect parameter declarations programmatically:

const op = document.httpApi.findOperation('/customers', 'get');
for (const prm of op.parameters) {
  console.log(prm.name, prm.location, prm.type?.name);
}

→ HttpController · HttpOperation