Stream React Native Reference Documentation

Stream

Current Version: 11.6.1

Chilkat.Stream

Read, write, pipe, monitor, and control byte or text streams.

Chilkat.Stream is a general-purpose streaming object for moving data between sources and sinks without requiring the entire payload to be handled at once. A stream can read from files, byte arrays, strings, or other sources; write to files, memory, BinData, StringBuilder, or other sinks; handle binary and text data; apply character-set rules for strings; process file parts; track bytes sent and received; and support timeouts, polling, aborts, async task integration, and end-of-stream handling.

File and memory sources

Stream from a source file, byte array, string, or selected file part without manually loading or copying all data first.

File and object sinks

Write streamed data to a sink file, append to an existing file, or output to BinData, StringBuilder, bytes, or strings.

Binary reads and writes

Read or write raw bytes, fixed byte counts, encoded byte strings, individual bytes, or BinData content.

Text streaming

Read and write strings using StringCharset, optionally use a BOM, and read text until CRLF or a matching delimiter.

Timeouts and polling

Control read and write wait behavior, poll for immediately available data, and inspect read or write failure reasons.

Progress and lifecycle

Track bytes sent and received, detect end-of-stream or write-closed state, reset streams, close writing, and abort long-running operations.

Common pattern: Configure the stream's source and sink, set the character set or chunk size if needed, then read or write using the method that matches the data type: bytes, encoded bytes, strings, BinData, or StringBuilder. Check EndOfStream, ReadFailReason, WriteFailReason, NumReceived, NumSent, and LastErrorText to understand stream progress and failures.
Timeout note: For ReadTimeoutMs, a value of 0 means a polling read, not an infinite timeout. For WriteTimeoutMs, 0 means return immediately if the stream cannot be written to right away.

Object Creation

// npm install @chilkat/react-native react-native-nitro-modules
// (React Native 0.76+ with the New Architecture; then `pod install` for iOS.  The Chilkat
//  native library is downloaded and verified during the native build -- see the package README.)

import { Chilkat, Stream } from '@chilkat/react-native'

// Once per app start, before any other Chilkat call:
Chilkat.unlockBundle('Anything for 30-day trial')   // shorthand for new Global().unlockBundle(..)

const stream = new Stream()
// ... the native object is released when `stream` is garbage collected, or now with stream.dispose()
new Stream()

Creates the underlying native Chilkat object. Stream is a Nitro Module HybridObject: use it from the JavaScript thread only (it cannot be passed to a Worklet or another runtime). Every member is synchronous and blocks the JavaScript thread until Chilkat returns; a method that can take a while also exists as a ...Async twin returning a Promise, which runs the same call on a native worker thread so the UI keeps rendering. While such a call is pending, every other call on this object throws, except abort() and assigning onPercentDone / onProgressInfo.

dispose(): void

Releases the native object immediately instead of waiting for garbage collection (useful for a large BinData or an open socket). Calling it more than once is harmless; any other use of the object afterwards throws. An object with a pending ...Async call cannot be disposed until the promise settles.

Errors

A method that can fail throws a plain Error: a method whose only outcome is success or failure returns void and throws on failure; a method producing a string or an object returns it and throws where Chilkat would have returned null. The error's message is "Class.method(...): reason", where the reason is the last informative line of the object's lastErrorText, which holds the full Chilkat log of the failed call. A ...Async twin rejects its promise with the same Error instead of throwing. Properties never throw, and methods that answer a question (has..., is..., ...) return a plain boolean.

try {
  stream.someMethod(...)
} catch (e) {
  console.log((e as Error).message)   // Stream.someMethod(...): <reason>
  console.log(stream.lastErrorText)   // the full Chilkat log of the failed call
}

// The same call without blocking the JavaScript thread:
try {
  await stream.someMethodAsync(...)
} catch (e) {
  console.log((e as Error).message)   // Stream.someMethodAsync: <reason>
}

Properties

AbortCurrent
// read/write
abortCurrent: boolean
Introduced in version 9.5.0.58

When set to true, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to false when the next method is called. When the abort occurs, this property is reset to false. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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CanRead
// read-only
readonly canRead: boolean
Introduced in version 9.5.0.56

true if the stream supports reading. Otherwise false.

Note: A stream that supports reading, which has already reached the end-of-stream, will still have a CanRead value of true. This property indicates the stream's inherent ability, and not whether or not the stream can be read at a particular moment in time.

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CanWrite
// read-only
readonly canWrite: boolean
Introduced in version 9.5.0.56

true if the stream supports writing. Otherwise false.

Note: A stream that supports writing, which has already been closed for write, will still have a CanWrite value of true. This property indicates the stream's inherent ability, and not whether or not the stream can be written at a particular moment in time.

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DataAvailable
// read-only
readonly dataAvailable: boolean
Introduced in version 9.5.0.56

true if it is known for sure that data is ready and waiting to be read. false if it is not known for sure (it may be that data is immediately available, but reading the stream with a ReadTimeoutMs of 0, which is to poll the stream, is the way to find out).

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DebugLogFilePath
// read/write
debugLogFilePath: string

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

More Information and Examples
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DefaultChunkSize
// read/write
defaultChunkSize: number
Introduced in version 9.5.0.56

The default internal chunk size for reading or writing. The default value is 65536. If this property is set to 0, it will cause the default chunk size (65536) to be used. Note: The chunk size can have significant performance impact. If performance is an issue, be sure to experiment with different chunk sizes.

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EndOfStream
// read-only
readonly endOfStream: boolean
Introduced in version 9.5.0.56

true if the end-of-stream has already been reached. When the stream has already ended, all calls to Read* methods will return false with the ReadFailReason set to 3 (already at end-of-stream).

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HeartbeatMs
// read/write
heartbeatMs: number
Introduced in version 9.5.0.97

The interval in milliseconds between each AbortCheck event callback, which enables an application to abort certain method calls before they complete. By default, HeartbeatMs is set to 0, meaning no AbortCheck event callbacks will trigger.

More Information and Examples
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IsWriteClosed
// read-only
readonly isWriteClosed: boolean
Introduced in version 9.5.0.56

true if the stream is closed for writing. Once closed, no more data may be written to the stream.

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LastErrorHtml
// read-only
readonly lastErrorHtml: string

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
// read-only
readonly lastErrorText: string

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
// read-only
readonly lastErrorXml: string

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
// read/write
lastMethodSuccess: boolean

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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Length
// read/write
length: number
Introduced in version 9.5.0.56

The length (in bytes) of the stream's source. If unknown, then this property will have a value of -1. This property may be set by the application if it knows in advance the length of the stream.

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Length32
// read/write
length32: number
Introduced in version 9.5.0.58

The length (in bytes) of the stream's source. If unknown, then this property will have a value of -1. This property may be set by the application if it knows in advance the length of the stream.

Setting this property also sets the Length property (which is a 64-bit integer).

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NumReceived
// read-only
readonly numReceived: number
Introduced in version 9.5.0.56

The number of bytes received by the stream.

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NumSent
// read-only
readonly numSent: number
Introduced in version 9.5.0.56

The number of bytes sent by the stream.

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ReadFailReason
// read-only
readonly readFailReason: number
Introduced in version 9.5.0.56

This property is automatically set when a Read* method is called. It indicates the reason for failure. Possible values are:

    0>
  1. No failure (success)
  2. Timeout, or no data is immediately available for a polling read.
  3. Aborted by an application callback.
  4. Already at end-of-stream.
  5. Fatal stream error.
  6. Out-of-memory error (this is very unlikely).

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ReadTimeoutMs
// read/write
readTimeoutMs: number
Introduced in version 9.5.0.56

The maximum number of seconds to wait while reading. The default value is 30 seconds (i.e. 30000ms). A value of 0 indicates a poll. (A polling read is to return with a timeout if no data is immediately available.)

Important: For most Chilkat timeout related properties, a value of 0 indicates an infinite timeout. For this property, a value of 0 indicates a poll. If setting a timeout related property (or method argument) to zero, be sure to understand if 0 means wait forever or poll.

The timeout value is not a total timeout. It is the maximum time to wait while no additional data is forthcoming.

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SinkFile
// read/write
sinkFile: string
Introduced in version 9.5.0.56

Sets the sink to the path of a file. The file does not need to exist at the time of setting this property. The sink file will be automatically opened on demand, when the stream is first written.

Note: This property takes priority over other potential sinks. Make sure this property is set to an empty string if the stream's sink is to be something else.

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SinkFileAppend
// read/write
sinkFileAppend: boolean
Introduced in version 9.5.0.83

If true, the stream appends to the SinkFile rather than truncating and re-writing the sink file. The default value is false.

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SourceFile
// read/write
sourceFile: string
Introduced in version 9.5.0.56

Sets the source to the path of a file. The file does not need to exist at the time of setting this property. The source file will be automatically opened on demand, when the stream is first read.

Note: This property takes priority over other potential sources. Make sure this property is set to an empty string if the stream's source is to be something else.

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SourceFilePart
// read/write
sourceFilePart: number
Introduced in version 9.5.0.59

If the source is a file, then this property can be used to stream one part of the file. The SourceFilePartSize property defines the size (in bytes) of each part. The SourceFilePart and SourceFilePartSize have default values of 0, which means the entire SourceFile is streamed.

This property is a 0-based index. For example, if the SourceFilePartSize is 1000, then part 0 is for bytes 0 to 999, part 1 is for bytes 1000 to 1999, etc.

More Information and Examples
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SourceFilePartSize
// read/write
sourceFilePartSize: number
Introduced in version 9.5.0.59

If the source is a file, then this property, in conjunction with the SourceFilePart property, can be used to stream a single part of the file. This property defines the size (in bytes) of each part. The SourceFilePart and SourceFilePartSize have default values of 0, which means that by default, the entire SourceFile is streamed.

More Information and Examples
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StringBom
// read/write
stringBom: boolean
Introduced in version 9.5.0.56

If true, then include the BOM when creating a string source via SetSourceString where the charset is utf-8, utf-16, etc. (The term BOM stands for Byte Order Mark, also known as the preamble.) Also, if true, then include the BOM when writing a string via the WriteString method. The default value of this property is false.

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StringCharset
// read/write
stringCharset: string
Introduced in version 9.5.0.56

Indicates the expected character encoding, such as utf-8, windows-1256, utf-16, etc. for methods that read text such as: ReadString, ReadToCRLF, ReadUntilMatch. Also controls the character encoding when writing strings with the WriteString method. The supported charsets are indicated at the link below.

The default value is utf-8.

More Information and Examples
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VerboseLogging
// read/write
verboseLogging: boolean

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
// read-only
readonly version: string

Version of the component/library, such as "10.1.0"

More Information and Examples
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WriteFailReason
// read-only
readonly writeFailReason: number
Introduced in version 9.5.0.56

This property is automatically set when a Write* method is called. It indicates the reason for failure. Possible values are:

    0>
  1. No failure (success)
  2. Timeout, or unable to immediately write when the WriteTimeoutMs is 0.
  3. Aborted by an application callback.
  4. The stream has already ended.
  5. Fatal stream error.
  6. Out-of-memory error (this is very unlikely).

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WriteTimeoutMs
// read/write
writeTimeoutMs: number
Introduced in version 9.5.0.56

The maximum number of seconds to wait while writing. The default value is 30 seconds (i.e. 30000ms). A value of 0 indicates to return immediately if it is not possible to write to the sink immediately.

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Methods

ReadBd
readBd(binData: BinData): void
Introduced in version 9.5.0.67

Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The incoming data is appended to binData.

Returns normally on success; throws an Error on failure.

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ReadBdAsync
readBdAsync(binData: BinData): Promise<void>
Introduced in version 9.5.0.67

Asynchronous form of ReadBd: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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ReadBytesENC
readBytesENC(encoding: string): string
Introduced in version 9.5.0.56

The same as ReadBytes, except returns the received bytes in encoded string form. The encoding argument indicates the encoding, which can be base64, hex, or any of the multitude of encodings indicated in the link below.

Throws an Error on failure (where the description says null is returned, the method throws instead).

More Information and Examples
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ReadBytesENCAsync
readBytesENCAsync(encoding: string): Promise<string>
Introduced in version 9.5.0.56

Asynchronous form of ReadBytesENC: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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ReadNBytesENC
readNBytesENC(numBytes: number, encoding: string): string
Introduced in version 9.5.0.56

The same as ReadNBytes, except returns the received bytes in encoded string form. The encoding argument indicates the encoding, which can be base64, hex, or any of the multitude of encodings indicated in the link below.

Throws an Error on failure (where the description says null is returned, the method throws instead).

More Information and Examples
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ReadNBytesENCAsync
readNBytesENCAsync(numBytes: number, encoding: string): Promise<string>
Introduced in version 9.5.0.56

Asynchronous form of ReadNBytesENC: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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ReadSb
readSb(sb: StringBuilder): void
Introduced in version 9.5.0.67

Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is appended to sb. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadSb.

Returns normally on success; throws an Error on failure.

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ReadSbAsync
readSbAsync(sb: StringBuilder): Promise<void>
Introduced in version 9.5.0.67

Asynchronous form of ReadSb: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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ReadString
readString(): string
Introduced in version 9.5.0.56

Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.

Throws an Error on failure (where the description says null is returned, the method throws instead).

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ReadStringAsync
readStringAsync(): Promise<string>
Introduced in version 9.5.0.56

Asynchronous form of ReadString: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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ReadToCRLF
readToCRLF(): string
Introduced in version 9.5.0.56

Reads the stream until a CRLF is received. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.

Note: If the end-of-stream is reached prior to receiving the CRLF, then the remaining data is returned, and the ReadFailReason property will be set to 3 (to indicate end-of-file). This is the only case where as string would be returned that does not end with CRLF.

Throws an Error on failure (where the description says null is returned, the method throws instead).

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ReadToCRLFAsync
readToCRLFAsync(): Promise<string>
Introduced in version 9.5.0.56

Asynchronous form of ReadToCRLF: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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ReadUntilMatch
readUntilMatch(matchStr: string): string
Introduced in version 9.5.0.56

Reads the stream until the string indicated by matchStr is received. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.

Note: If the end-of-stream is reached prior to receiving the match string, then the remaining data is returned, and the ReadFailReason property will be set to 3 (to indicate end-of-file). This is the only case where as string would be returned that does not end with the desired match string.

Throws an Error on failure (where the description says null is returned, the method throws instead).

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ReadUntilMatchAsync
readUntilMatchAsync(matchStr: string): Promise<string>
Introduced in version 9.5.0.56

Asynchronous form of ReadUntilMatch: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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Reset
reset(): void
Introduced in version 9.5.0.56

Resets the stream. If a source or sink is open, then it is closed. Properties such as EndOfStream and IsWriteClose are reset to default values.

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SetSourceString
setSourceString(srcStr: string, charset: string): void
Introduced in version 9.5.0.56

Sets the stream's source to the contents of srcStr. The charset indicates the character encoding to be used for the byte representation of the srcStr.

Returns normally on success; throws an Error on failure.

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WriteBd
writeBd(binData: BinData): void
Introduced in version 9.5.0.67

Writes the contents of binData to the stream.

Returns normally on success; throws an Error on failure.

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WriteBdAsync
writeBdAsync(binData: BinData): Promise<void>
Introduced in version 9.5.0.67

Asynchronous form of WriteBd: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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WriteByte
writeByte(byteVal: number): void
Introduced in version 9.5.0.56

Writes a single byte to the stream. The byteVal must have a value from 0 to 255.

Returns normally on success; throws an Error on failure.

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WriteByteAsync
writeByteAsync(byteVal: number): Promise<void>
Introduced in version 9.5.0.56

Asynchronous form of WriteByte: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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WriteBytes2
writeBytes2(byteData: ArrayBuffer): void
Introduced in version 9.5.0.82

Writes binary bytes to a stream.

Returns normally on success; throws an Error on failure.

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WriteBytesENC
writeBytesENC(byteData: string, encoding: string): void
Introduced in version 9.5.0.56

Writes binary bytes to a stream. The byte data is passed in encoded string form, where the encoding can be base64, hex, or any of the supported binary encodings listed at the link below.

Returns normally on success; throws an Error on failure.

More Information and Examples
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WriteBytesENCAsync
writeBytesENCAsync(byteData: string, encoding: string): Promise<void>
Introduced in version 9.5.0.56

Asynchronous form of WriteBytesENC: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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WriteClose
writeClose(): void
Introduced in version 9.5.0.56

Indicates that no more data will be written to the stream.

Returns normally on success; throws an Error on failure.

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WriteSb
writeSb(sb: StringBuilder): void
Introduced in version 9.5.0.67

Writes the contents of sb to the stream. The actual bytes written are the byte representation of the string as indicated by the StringCharset property. For example, to write utf-8 bytes, first set StringCharset equal to utf-8 and then call WriteSb.

Returns normally on success; throws an Error on failure.

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WriteSbAsync
writeSbAsync(sb: StringBuilder): Promise<void>
Introduced in version 9.5.0.67

Asynchronous form of WriteSb: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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WriteString
writeString(str: string): void
Introduced in version 9.5.0.56

Writes a string to a stream. The actual bytes written are the byte representation of the string as indicated by the StringCharset property. For example, to write utf-8 bytes, first set StringCharset equal to utf-8 and then call WriteString.

Returns normally on success; throws an Error on failure.

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WriteStringAsync
writeStringAsync(str: string): Promise<void>
Introduced in version 9.5.0.56

Asynchronous form of WriteString: the same call on a native worker thread, so the JavaScript thread (and the UI) stays responsive. Takes the same arguments and resolves with the same result. While the returned Promise is pending, every other call on this object throws (the object is busy), except abort(), which cancels the call, and assigning the onPercentDone / onProgressInfo callbacks, which report its progress.

Note: the onPercentDone and onProgressInfo callbacks run on the JavaScript thread while the promise is pending, so they can update the UI directly. A rejection's message is "Class.methodAsync: reason"; the full log is in lastErrorText.

Returns a Promise that resolves with the synchronous method's result (undefined for a void method) and rejects with an Error where the synchronous method would throw.

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Events

While a method runs, Stream reports progress through two optional callback properties. Assign a function to receive the event, or undefined to stop receiving it. The callbacks are delivered on the JavaScript thread, so they are useful with the ...Async methods: during a synchronous call the JavaScript thread is busy inside Chilkat, and the events can only arrive after it returns.

const stream = new Stream()
stream.onPercentDone = (pct) => setProgress(pct)          // pct is 0..100
stream.onProgressInfo = (name, value) => console.log(`${name}: ${value}`)
stream.heartbeatMs = 250   // let abort() take effect within a quarter second

const pending = stream.someMethodAsync(...)
cancelButton.onPress = () => stream.abort()   // the promise then rejects
await pending

PercentDone fires when an operation's completion percentage is known; ProgressInfo delivers named progress values (what is reported depends on the class and method). There is no AbortCheck callback: to cancel a pending ...Async call, call abort() on the object. Chilkat notices the request at its next progress check, which happens at least every heartbeatMs milliseconds on the classes that have that property (0, the default, disables the heartbeat, so set it for a responsive cancel), and the promise rejects with Chilkat's abort error. abort() is harmless when nothing is pending.

PercentDone
// callback property; assign undefined to remove
onPercentDone?: (pctDone: number) => void

This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pctDone argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pctDone equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).

The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.

To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.

More Information and Examples

Example:

stream.onPercentDone = (pct) => {
  // pct ranges from 0 to 100.
  setProgress(pct)   // runs on the JavaScript thread: React state may be updated directly
}
await stream.someMethodAsync(...)
// To stop an operation from within the callback, call stream.abort()
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ProgressInfo
// callback property; assign undefined to remove
onProgressInfo?: (name: string, value: string) => void

This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.

Note: Some Chilkat methods don't fire any ProgressInfo events.

More Information and Examples

Example:

stream.onProgressInfo = (name, value) => console.log(`${name}: ${value}`)
await stream.someMethodAsync(...)
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