Encoding of types

This document describe how the http library interpret TypeSpec built-in types and how to configure

bytes

Default behavior:

• bytes are serialized as base64 when used inside a model serialized as JSON
• In request or response body it represent a binary payload.

Note

This behavior is only a specification and MUST be respected by the emitter. The http library DOES NOT automatically apply the @encode("base64") when used inside a JSON model.

Use @encode to configure

model Pet {
  icon: bytes; // Serialize as base64
  @encode(BytesKnownEncoding.base64url) // Serialize as base64url
  other: bytes;
}

op read(): Pet;

op download(): bytes; // Return application/octet-stream
op upload(@body data: bytes): void; // Accept application/octet-stream

utcDatetime and offsetDateTime

Default behavior:

• Encoded as rfc7231 when used in a header
• Encoded as rfc3339 otherwise.

Note

This behavior is only a specification and MUST be respected by the emitter. The http library DOES NOT automatically apply the @encode("rfc7231") on utcDatetime and offsetDateTime when used in a header.

Use @encode to configure.

TypeSpec

Example payload

model User { // Headers @header("Created-At") createdAtHeader: utcDateTime; @header("Created-At-Rfc3339") @encode(DateTimeKnownEncoding.rfc3339) createdAtHeaderRfc3339Encoding: utcDateTime; // In Json payload createdAt: utcDateTime; // rfc3339 updatedAt: offsetDateTime; // rfc3339 @encode(DateTimeKnownEncoding.rfc7231) createdAtPretty: utcDateTime; // rfc7231 @encode(DateTimeKnownEncoding.rfc7231) updatedAtPretty: offsetDateTime; // rfc7231 @encode(DateTimeKnownEncoding.unixTimestamp, int32) createdAtUnix: utcDateTime; // unixTime in seconds }

Created-At: Wed, 12 Oct 2022 07:20:50 GMT Created-At-Rfc3339: 2022-10-12T07:20:50.52Z { "createdAt": "2022-10-12T07:20:50.52Z", "updatedAt": "2022-10-25T07:20:50.52+07:00", "createdAtPretty": "Wed, 12 Oct 2022 07:20:50 GMT", "updatedAtPretty": "Tue, 25 Oct 2022 00:20:50 GMT", "createdAtUnix": 1493938410 }

duration

Default behavior:

• Encoded as ISO8601

Use @encode to configure.

TypeSpec	Example payload
model User { runtime: duration; // ISO8601 @encode(DurationKnownEncoding.seconds, int32) runtimeInSecondsInt: duration; // in seconds as an int32 @encode(DurationKnownEncoding.seconds, float32) runtimeInSecondsFloat: duration; // in seconds as a float32 }	{ "runtime": "PT5M5S", "runtimeInSecondsInt": "305", "runtimeInSecondsFloat": "305.0" }

Numeric types ( int64, decimal128, float64, etc.)

By default numeric types are serialized as a JSON number. However for large types like int64 or decimal128 that cannot be represented in certain languages like JavaScript it is recommended to serialize them as string over the wire.

TypeSpec	Example payload
model User { id: int64; // JSON number @encode(string) idAsString: int64; // JSON string viaSalar: decimalString; } @encode(string) scalar decimalString extends decimal128;	{ "id": 1234567890123456789012345678901234567890, "idAsString": "1234567890123456789012345678901234567890", "viaSalar": "1.3" }