StreamingOperationContext

@webda/core

---

Abstract Class: StreamingOperationContext

Defined in: packages/core/src/contexts/streamingcontext.ts:30

The shared part of a context serving a streaming operation over a transport (gRPC, WebSocket, GraphQL subscription, ...):

• a non-streamed result is buffered as usual (writeResult())
• a streamed chunk is sent right away (sendChunk()), write() returning false under backpressure
• drained() waits for the transport (waitForDrain()) without leaving listeners behind: the signal it gets is aborted once the wait is over
• once cancelled (the client went away) or once the connection is over (connectionEnded), write() and drained() throw OperationCancelledError

The transport calls cancel() when the client leaves, and also ends the operation's input queue so its pending read returns and its finally blocks run.

Extends

• WebContext

Extended by

• WebSocketOperationContext

Properties

_body

protected _body: string

Defined in: packages/core/src/contexts/operationcontext.ts:49

Output

Inherited from

WebContext._body

---

_cookie

_cookie: Map<string, Cookie>

Defined in: packages/core/src/contexts/webcontext.ts:38

Cookies to send back

Inherited from

WebContext._cookie

---

_ended

_ended: Promise<any> = undefined

Defined in: packages/core/src/contexts/webcontext.ts:45

Inherited from

WebContext._ended

---

_outputHeaders

protected _outputHeaders: OutgoingHttpHeaders

Defined in: packages/core/src/contexts/webcontext.ts:29

Contains the response headers

Inherited from

WebContext._outputHeaders

---

_promises

_promises: Promise<any>[]

Defined in: packages/core/src/contexts/icontext.ts:33

Contain all registered promises to this context

Inherited from

WebContext._promises

---

_route

_route: any

Defined in: packages/core/src/contexts/webcontext.ts:43

Inherited from

WebContext._route

---

_sanitized

protected _sanitized: any

Defined in: packages/core/src/contexts/operationcontext.ts:44

Contain the sanitized request body if computed

Inherited from

WebContext._sanitized

---

_sessionSaved

protected _sessionSaved: boolean = false

Defined in: packages/core/src/contexts/webcontext.ts:49

Whether the session was already saved

Inherited from

WebContext._sessionSaved

---

_stream

_stream: Writable

Defined in: packages/core/src/contexts/operationcontext.ts:85

Output stream

Inherited from

WebContext._stream

---

caches

caches: any

Defined in: packages/core/src/contexts/icontext.ts:19

Get the caches linked to the context

Inherited from

WebContext.caches

---

extensions

protected extensions: object

Defined in: packages/core/src/contexts/icontext.ts:23

Allow extensions

Index Signature

[key: string]: any

Inherited from

WebContext.extensions

---

flushed

protected flushed: boolean = false

Defined in: packages/core/src/contexts/icontext.ts:37

If the headers were flushed

Inherited from

WebContext.flushed

---

headers

headers: Map<string, string>

Defined in: packages/core/src/contexts/webcontext.ts:42

Inherited from

WebContext.headers

---

headersFlushed

protected headersFlushed: boolean

Defined in: packages/core/src/contexts/webcontext.ts:54

If headers were flushed

Inherited from

WebContext.headersFlushed

---

parameters

parameters: any

Defined in: packages/core/src/contexts/operationcontext.ts:56

Inherited from

WebContext.parameters

---

session

protected session: Session

Defined in: packages/core/src/contexts/operationcontext.ts:40

Session

Inherited from

WebContext.session

---

statusCode

statusCode: number

Defined in: packages/core/src/contexts/webcontext.ts:34

Current status code

Inherited from

WebContext.statusCode

Accessors

connectionEnded

Get Signature

get abstract protected connectionEnded(): boolean

Defined in: packages/core/src/contexts/streamingcontext.ts:48

Returns

boolean

true when nothing can be sent anymore although the context was not cancelled (response or socket over)

---

isCancelled

Get Signature

get isCancelled(): boolean

Defined in: packages/core/src/contexts/streamingcontext.ts:36

Returns

boolean

whether the client went away

Methods

addAsyncRequest()

addAsyncRequest(promise): void

Defined in: packages/core/src/contexts/operationcontext.ts:136

Register a promise with the context

Parameters

promise

any

the promise to add

Returns

void

Inherited from

WebContext.addAsyncRequest

---

assertAlive()

protected assertAlive(): void

Defined in: packages/core/src/contexts/streamingcontext.ts:78

Returns

void

Throws

OperationCancelledError when the client went away or the connection is over

---

cancel()

cancel(): void

Defined in: packages/core/src/contexts/streamingcontext.ts:41

The client went away: the next write or drain throws.

Returns

void

---

clearInput()

clearInput(): void

Defined in: packages/core/src/contexts/operationcontext.ts:161

Remove the input

Returns

void

Inherited from

WebContext.clearInput

---

cookie()

cookie(param, value, options?): void

Defined in: packages/core/src/contexts/webcontext.ts:185

For compatibility reason

Parameters

param

any

the parameter name

value

any

the value to set

options?

any = undefined

the options

Returns

void

Inherited from

WebContext.cookie

---

createStream()

createStream(): void

Defined in: packages/core/src/contexts/operationcontext.ts:286

Create a buffer stream

Returns

void

Inherited from

WebContext.createStream

---

drained()

drained(): Promise<void>

Defined in: packages/core/src/contexts/streamingcontext.ts:101

Wait for the transport to take more output, without leaving listeners behind

Returns

Promise<void>

Throws

OperationCancelledError when the client went away, the connection is over or the transport failed

Overrides

WebContext.drained

---

end()

end(): Promise<any>

Defined in: packages/core/src/contexts/webcontext.ts:277

Flush the request

Returns

Promise<any>

the result

Emits

'finish' event

Throws

Error if the request was already ended

Inherited from

WebContext.end

---

flushHeaders()

flushHeaders(): Promise<void>

Defined in: packages/core/src/contexts/webcontext.ts:406

Returns

Promise<void>

Inherited from

WebContext.flushHeaders

---

getCurrentUser()

getCurrentUser<K>(refresh?): Promise<K>

Defined in: packages/core/src/contexts/operationcontext.ts:351

Get the current user from session

Type Parameters

K

K extends IUser

Parameters

refresh?

boolean = false

whether to refresh

Returns

Promise<K>

the result

Inherited from

WebContext.getCurrentUser

---

getCurrentUserId()

getCurrentUserId(): string

Defined in: packages/core/src/contexts/operationcontext.ts:371

Get the current user id from session

A session waiting for its second factor (mfa: "pending") is not logged: it has no current user. Code that needs the pending user reads getSession().userId.

Returns

string

the result

Inherited from

WebContext.getCurrentUserId

---

getExtension()

getExtension<K>(name): K

Defined in: packages/core/src/contexts/operationcontext.ts:91

Get an extension of the context

Type Parameters

K

K = any

Parameters

name

string

of the extension

Returns

K

extension object

Inherited from

WebContext.getExtension

---

getHttpContext()

getHttpContext(): HttpContext

Defined in: packages/core/src/contexts/webcontext.ts:71

Get current http context

Returns

HttpContext

the result

Inherited from

WebContext.getHttpContext

---

getInput()

getInput(sanitizedOptions?): Promise<any>

Defined in: packages/core/src/contexts/webcontext.ts:97

A multipart body (file upload) is never JSON: return the default value instead of letting the parent try to JSON.parse it and log an error. The raw body stays available to getRawInput()/getRawStream().

Parameters

sanitizedOptions?

IOptions & object

Returns

Promise<any>

Inherited from

WebContext.getInput

---

getLocale()

getLocale(): string

Defined in: packages/core/src/contexts/webcontext.ts:359

Get the request locale if found

Returns

string

the result

Inherited from

WebContext.getLocale

---

getOutput()

getOutput(): string

Defined in: packages/core/src/contexts/operationcontext.ts:144

Get output as string, if a OutputStream is provided it will returned null

Returns

string

the result string

Inherited from

WebContext.getOutput

---

getOutputStream()

getOutputStream(): Promise<Writable>

Defined in: packages/core/src/contexts/operationcontext.ts:251

Get the HTTP stream to output raw data

Returns

Promise<Writable>

the result

Inherited from

WebContext.getOutputStream

---

getParameters()

getParameters(): any

Defined in: packages/core/src/contexts/operationcontext.ts:109

Get the parameters

Returns

any

the result

Inherited from

WebContext.getParameters

---

getRawInput()

getRawInput(limit?, timeout?): Promise<Buffer<ArrayBufferLike>>

Defined in: packages/core/src/contexts/webcontext.ts:107

Parameters

limit?

number = ...

timeout?

number = 60000

Returns

Promise<Buffer<ArrayBufferLike>>

Inherited from

WebContext.getRawInput

---

getRawInputAsString()

getRawInputAsString(limit?, timeout?, encoding?): Promise<string>

Defined in: packages/core/src/contexts/webcontext.ts:83

Get the raw input as string

Any WHATWG Encoding Standard label is accepted as encoding (utf-8, iso-8859-1, shift_jis, ...) If no encoding is given, the charset of the Content-Type header is used, falling back to UTF-8

Parameters

limit?

number = ...

timeout?

number = 60000

encoding?

string

Returns

Promise<string>

Inherited from

WebContext.getRawInputAsString

---

getRawStream()

getRawStream(): Readable

Defined in: packages/core/src/contexts/webcontext.ts:114

Returns

Readable

Inherited from

WebContext.getRawStream

---

getRequest()

getRequest(): IncomingMessage

Defined in: packages/core/src/contexts/webcontext.ts:333

Retrieve a http.IncomingMessage valid from Context

Need more testing

Returns

IncomingMessage

the result

Inherited from

WebContext.getRequest

---

getRequestBody()

getRequestBody(sanitizedOptions?): Promise<any>

Defined in: packages/core/src/contexts/webcontext.ts:307

Alias to keep compatibility with WebContext

Parameters

sanitizedOptions?

any = ...

the sanitized options

Returns

Promise<any>

the result

Inherited from

WebContext.getRequestBody

---

getResponseBody()

getResponseBody(): any

Defined in: packages/core/src/contexts/webcontext.ts:320

Get request body

Returns

any

the result

Inherited from

WebContext.getResponseBody

---

getResponseCode()

getResponseCode(): number

Defined in: packages/core/src/contexts/webcontext.ts:168

Returns

number

the result

Inherited from

WebContext.getResponseCode

---

getResponseCookies()

getResponseCookies(): Map<string, Cookie>

Defined in: packages/core/src/contexts/webcontext.ts:197

Get all cookies set on the response

Returns

Map<string, Cookie>

the result map

Inherited from

WebContext.getResponseCookies

---

getResponseHeaders()

getResponseHeaders(): OutgoingHttpHeaders

Defined in: packages/core/src/contexts/webcontext.ts:399

Return the merged response headers — defaults set by the constructor (_outputHeaders) overlaid with any headers added via setHeader() / writeHead(). Same merge order as flushHeaders writes to the wire, so callers (logging, capture, transports) see exactly what the client will receive.

Returns

OutgoingHttpHeaders

the merged response headers

Inherited from

WebContext.getResponseHeaders

---

getResponseSize()

getResponseSize(): number

Defined in: packages/core/src/contexts/webcontext.ts:248

Return the response size

Returns

number

the result

Inherited from

WebContext.getResponseSize

---

getSession()

getSession<K>(): K

Defined in: packages/core/src/contexts/operationcontext.ts:260

Get linked session

Type Parameters

K

K = Session

Returns

K

the result

Inherited from

WebContext.getSession

---

getSetCookieHeaders()

getSetCookieHeaders(): string[]

Defined in: packages/core/src/contexts/webcontext.ts:205

The Set-Cookie header values of the response, one per cookie

Returns

string[]

the serialized cookies

Inherited from

WebContext.getSetCookieHeaders

---

hasFlushedHeaders()

hasFlushedHeaders(): boolean

Defined in: packages/core/src/contexts/webcontext.ts:373

Return true if Headers got flushed already

Returns

boolean

the result

Inherited from

WebContext.hasFlushedHeaders

---

init()

init(force?): Promise<StreamingOperationContext>

Defined in: packages/core/src/contexts/webcontext.ts:454

Initialize the web context, loading session and setting up stream listeners

Parameters

force?

boolean = false

whether to force the operation

Returns

Promise<StreamingOperationContext>

this for chaining

Inherited from

WebContext.init

---

isEnded()

isEnded(): Promise<any>

Defined in: packages/core/src/contexts/webcontext.ts:213

Whether the response has been ended

Returns

Promise<any>

the result

Inherited from

WebContext.isEnded

---

isGlobalContext()

isGlobalContext(): boolean

Defined in: packages/core/src/contexts/icontext.ts:43

Whether this is the global (non-request-scoped) context

Returns

boolean

true if the condition is met

Inherited from

WebContext.isGlobalContext

---

json()

json(obj): this

Defined in: packages/core/src/contexts/webcontext.ts:239

Express response allow answer to be sent this way

Parameters

obj

any

the target object

Returns

this

this for chaining

Inherited from

WebContext.json

---

newSession()

newSession(): Session

Defined in: packages/core/src/contexts/operationcontext.ts:268

Create and assign a new empty session

Returns

Session

the result

Inherited from

WebContext.newSession

---

parameter()

parameter(name, defaultValue?): any

Defined in: packages/core/src/contexts/operationcontext.ts:101

Get one parameter

Parameters

name

string

the name to use

defaultValue?

any = undefined

the default value

Returns

any

the result

Inherited from

WebContext.parameter

---

pipeline()

pipeline(stream1, ...streams): Promise<void>

Defined in: packages/core/src/contexts/icontext.ts:149

Pipeline streams into the output stream

Parameters

stream1

ReadableStream

the first stream

streams

...(ReadWriteStream | PipelineOptions)[]

additional streams

Returns

Promise<void>

See

https://nodejs.org/api/stream.html#streampipelinestreams-options

Inherited from

WebContext.pipeline

---

redirect()

redirect(url): void

Defined in: packages/core/src/contexts/webcontext.ts:176

Redirect to another url

Parameters

url

string

the URL

Returns

void

Inherited from

WebContext.redirect

---

registerPromise()

registerPromise(promise): void

Defined in: packages/core/src/contexts/icontext.ts:56

Register a promise with the context

Parameters

promise

any

the promise to add

Returns

void

Inherited from

WebContext.registerPromise

---

reinit()

reinit(): void

Defined in: packages/core/src/contexts/operationcontext.ts:276

Remove sanitized body

Returns

void

Inherited from

WebContext.reinit

---

resetResponse()

resetResponse(): void

Defined in: packages/core/src/contexts/webcontext.ts:121

Remove everything that was about to be sent

Returns

void

Inherited from

WebContext.resetResponse

---

saveSession()

saveSession(): Promise<void>

Defined in: packages/core/src/contexts/webcontext.ts:257

Save the session through the SessionManager, once

The SessionManager writes the session cookie: call it before the headers are flushed

Returns

Promise<void>

Inherited from

WebContext.saveSession

---

sendChunk()

abstract protected sendChunk(chunk): boolean

Defined in: packages/core/src/contexts/streamingcontext.ts:55

Send one streamed chunk now

Parameters

chunk

any

what the operation wrote

Returns

boolean

false when the transport asks the operation to wait for drained()

---

setExtension()

setExtension(name, extension): this

Defined in: packages/core/src/contexts/operationcontext.ts:127

Parameters

name

string

to add

extension

any

object to store

Returns

this

this for chaining

Inherited from

WebContext.setExtension

---

setFlushedHeaders()

setFlushedHeaders(status?): void

Defined in: packages/core/src/contexts/webcontext.ts:381

Set flushed header status

Parameters

status?

boolean = true

the HTTP status code

Returns

void

Inherited from

WebContext.setFlushedHeaders

---

setHeader()

setHeader(name, value): void

Defined in: packages/core/src/contexts/icontext.ts:104

Set a header in the response

Parameters

name

string

the name to use

value

string | number | string[]

the value to set

Returns

void

Inherited from

WebContext.setHeader

---

setHttpContext()

setHttpContext(httpContext): void

Defined in: packages/core/src/contexts/webcontext.ts:62

Set current http context

Parameters

httpContext

HttpContext

current http context

Returns

void

Inherited from

WebContext.setHttpContext

---

setParameters()

setParameters(params): void

Defined in: packages/core/src/contexts/operationcontext.ts:117

Set the parameters

Parameters

params

any

the service parameters

Returns

void

Inherited from

WebContext.setParameters

---

setSession()

setSession(session): void

Defined in: packages/core/src/contexts/operationcontext.ts:78

Set the session

Parameters

session

Session

the session object

Returns

void

Inherited from

WebContext.setSession

---

status()

status(code): this

Defined in: packages/core/src/contexts/webcontext.ts:228

Express response allow statusCode to be defined this way

Parameters

code

number

to return

Returns

this

this for chaining

Inherited from

WebContext.status

---

waitForDrain()

abstract protected waitForDrain(signal): Promise<void>

Defined in: packages/core/src/contexts/streamingcontext.ts:62

Wait until the transport can take more output

Parameters

signal

AbortSignal

aborted once the wait is over: listeners registered with it are removed

Returns

Promise<void>

Throws

any error when the transport failed or closed (reported as OperationCancelledError)

---

write()

write(output, encoding?, cb?): boolean

Defined in: packages/core/src/contexts/streamingcontext.ts:90

Streamed chunks go out immediately; a non-streamed result is buffered

Parameters

output

any

encoding?

string

cb?

(error) => void

Returns

boolean

Throws

OperationCancelledError when streaming and the client went away or the connection is over

Overrides

WebContext.write

---

writeHead()

writeHead(statusCode, headers?): this

Defined in: packages/core/src/contexts/webcontext.ts:154

Write the http return code and some headers Those headers are not flushed yet so can still be overwritten

Parameters

statusCode

number

to return to the client

headers?

OutgoingHttpHeaders = undefined

to add to the response

Returns

this

this for chaining

Inherited from

WebContext.writeHead

---

writeResult()

protected writeResult(output, encoding?, cb?): boolean

Defined in: packages/core/src/contexts/streamingcontext.ts:71

Keep a non-streamed result

Parameters

output

any

the result

encoding?

string

the encoding to use

cb?

(error) => void

the callback function

Returns

boolean

true