Upload Lianja Reference Documentation

Upload

Current Version: 10.0.0

This is a class to upload files over HTTP and HTTPS to a web server.

Supports both HTTP and HTTPS protocols.
Progress monitoring with percentage completion and "heartbeat" monitoring.
Abort capability.
Asynchronous uploads with real-time monitoring of percentage completion and number of bytes transferred.
Add arbitrary HTTP POST form parameters to your upload.
Upload multiple files in a single transaction.
Add arbitrary (custom) HTTP header fields to the HTTP upload.
Retrieve the HTTP response status, header, and body returned by the web server.

Object Creation

loObject = createobject("CkUpload")

Properties

AbortCurrent

AbortCurrent As Boolean

Introduced in version 9.5.0.58

When set to .T., 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 .F. when the next method is called. When the abort occurs, this property is reset to .F.. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

BandwidthThrottleUp

BandwidthThrottleUp As Numeric

Introduced in version 9.5.0.49

If non-zero, limits (throttles) the upload bandwidth to approximately this maximum number of bytes per second. The default value of this property is 0.

More Information and Examples

Bandwidth Throttled Asynchronous HTTP Upload

ChunkSize

ChunkSize As Numeric

The chunk size (in bytes) used by the underlying TCP/IP sockets for uploading files. The default value is 65535.

ClientIpAddress

ClientIpAddress As Character

Introduced in version 9.5.0.49

The IP address to use for computers with multiple network interfaces or IP addresses. For computers with a single network interface (i.e. most computers), this property should not be set. For multihoming computers, the default IP address is automatically used if this property is not set.

The IP address is a string such as in dotted notation using numbers, not domain names, such as "165.164.55.124".

CurrentFilename

CurrentFilename As Character (read-only)

Introduced in version 9.5.0.90

The current filename being uploaded while an asynchronous upload is in progress.

DebugLogFilePath

DebugLogFilePath As Character

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
there is an internal problem (bug) in the Chilkat code that causes the hang.

More Information and Examples

Example showing how to use DebugLogFilePath.

Expect100Continue

Expect100Continue As Boolean

When .T., the request header will included an "Expect: 100-continue" header field. This indicates that the server should respond with an intermediate response of "100 Continue" or "417 Expectation Failed" response based on the information available in the request header. This helps avoid situations such as limits on upload sizes. It allows the server to reject the upload, and then the client can abort prior to uploading the data.

The default value of this property is .T..

Hostname

Hostname As Character

The hostname of the HTTP server that is the target of the upload. Do not include "http://" in the hostname. It can be a hostname, such as "www.chilkatsoft.com", or an IP address, such as "168.144.70.227".

IdleTimeoutMs

IdleTimeoutMs As Numeric

A timeout in milliseconds. The default value is 30000. If the upload hangs (i.e. progress halts) for more than this time, the component will abort the upload. (It will timeout.)

LastErrorHtml

LastErrorHtml As Character (read-only)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

LastErrorText

LastErrorText As Character (read-only)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

LastErrorXml As Character (read-only)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

LastMethodSuccess

LastMethodSuccess As Boolean

Indicate whether the last method call succeeded or failed. A value of .T. indicates success, a value of .F. indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

Any method that returns a string.
Any method returning a Chilkat object, binary bytes, or a date/time.
Any method returning a standard boolean status value where success = .T. and failure = .F..
Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to .T.. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

Login

Login As Character

The HTTP login for sites requiring authentication. Chilkat Upload supports Basic HTTP authentication.

NumBytesSent

NumBytesSent As Numeric (read-only)

After an upload has completed, this property contains the number of bytes sent. During asynchronous uploads, this property contains the current number of bytes sent while the upload is in progress.

Password

Password As Character

The HTTP password for sites requiring authentication. Chilkat Upload supports Basic HTTP authentication.

Path

Path As Character

The path part of the upload URL. Some examples:

If the upload target (i.e. consumer) URL is: http://www.freeaspupload.net/freeaspupload/testUpload.asp, then

Hostname = "www.freeaspupload.net" Path = "/freeaspupload/testUpload.asp"

If the upload target URL is https://www.chilkatsoft.com/cgi-bin/ConsumeUpload.exe, then

Hostname = "www.chilkatsoft.com" Path = "/cgi-bin/ConsumeUpload.exe"

PercentUploaded

PercentUploaded As Numeric (read-only)

Contains the current percentage completion (0 to 100) while an asynchronous upload is in progress.

Port

Port As Numeric

The port number of the upload target (i.e. consumer) URL. The default value is 80. If SSL is used, this should be set to 443 (typically).

PreferIpv6

PreferIpv6 As Boolean

If .T., then use IPv6 over IPv4 when both are supported for a particular domain. The default value of this property is .F., which will choose IPv4 over IPv6.

ProxyDomain

ProxyDomain As Character

The domain name of a proxy host if an HTTP proxy is used. Do not include the "http://". The domain name may be a hostname, such as "www.chilkatsoft.com", or an IP address, such as "168.144.70.227".

ProxyLogin

ProxyLogin As Character

If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy login.

ProxyPassword

ProxyPassword As Character

If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy password.

ProxyPort

ProxyPort As Numeric

The port number of a proxy server if an HTTP proxy is used.

ResponseBodyStr

ResponseBodyStr As Character (read-only)

Introduced in version 9.5.0.83

Returns the response body as a string.

ResponseHeader

ResponseHeader As Character (read-only)

An HTTP upload is nothing more than an HTTP POST that contains the content of the files being uploaded. Just as with any HTTP POST or GET, the server should send an HTTP response that consists of header and body.

This property contains the header part of the HTTP response.

ResponseStatus

ResponseStatus As Numeric (read-only)

The HTTP response status code of the HTTP response. A list of HTTP status codes can be found here: HTTP Response Status Codes.

Ssl

Ssl As Boolean

Set this to .T. if the upload is to HTTPS. For example, if the target of the upload is:

https://www.myuploadtarget.com/consumeUpload.asp

then set:

Ssl = .T.
Hostname = "www.myuploadtarget.com"
Path = "/consumeupload.asp"
Port = 443

SslAllowedCiphers

SslAllowedCiphers As Character

Introduced in version 9.5.0.55

Provides a means for setting a list of ciphers that are allowed for SSL/TLS connections. The default (empty string) indicates that all implemented ciphers are possible. The TLS ciphers supported in Chilkat v9.5.0.55 and later are:

TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_256_CBC_SHA256
TLS_RSA_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
TLS_RSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA
TLS_RSA_WITH_3DES_EDE_CBC_SHA
TLS_ECDHE_RSA_WITH_RC4_128_SHA
TLS_RSA_WITH_RC4_128_SHA
TLS_RSA_WITH_RC4_128_MD5
TLS_DHE_RSA_WITH_DES_CBC_SHA
TLS_RSA_WITH_DES_CBC_SHA

To restrict SSL/TLS connections to one or more specific ciphers, set this property to a comma-separated list of ciphers such as "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384". The order should be in terms of preference, with the preferred algorithms listed first. (Note that the client cannot specifically choose the algorithm is picked because it is the server that chooses. The client simply provides the server with a list from which to choose.)

The property can also disallow connections with servers having certificates with RSA keys less than a certain size. By default, server certificates having RSA keys of 512 bits or greater are allowed. Add the keyword "rsa1024" to disallow connections with servers having keys smaller than 1024 bits. Add the keyword "rsa2048" to disallow connections with servers having keys smaller than 2048 bits.

Note: Prior to Chilkat v9.5.0.55, it was not possible to explicitly list allowed cipher suites. The deprecated means for indicating allowed ciphers was both incomplete and unprecise. For example, the following keywords could be listed to allow matching ciphers: "aes256-cbc", "aes128-cbc", "3des-cbc", and "rc4". These keywords will still be recognized, but programs should be updated to explicitly list the allowed ciphers.

secure-renegotiation: Starting in Chilkat v9.5.0.55, the keyword "secure-renegotiation" may be added to require that all renegotions be done securely (as per RFC 5746).

best-practices: Starting in Chilkat v9.5.0.55, this property may be set to the single keyword "best-practices". This will allow ciphers based on the current best practices. As new versions of Chilkat are released, the best practices may change. Changes will be noted here. The current best practices are:

If the server uses an RSA key, it must be 1024 bits or greater.
All renegotations must be secure renegotiations.
All ciphers using RC4, DES, or 3DES are disallowed.

Example: The following string would restrict to 2 specific cipher suites, require RSA keys to be 1024 bits or greater, and require secure renegotiations: "TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, TLS_RSA_WITH_AES_256_CBC_SHA, rsa1024, secure-renegotiation"

SslProtocol

SslProtocol As Character

Introduced in version 9.5.0.55

Selects the secure protocol to be used for secure (SSL/TLS) connections. Possible values are:

default
TLS 1.3
TLS 1.2
TLS 1.1
TLS 1.0
SSL 3.0
TLS 1.3 or higher
TLS 1.2 or higher
TLS 1.1 or higher
TLS 1.0 or higher

The default value is "default" which will choose the, which allows for the protocol to be selected dynamically at runtime based on the requirements of the server. Choosing an exact protocol will cause the connection to fail unless that exact protocol is negotiated. It is better to choose "X or higher" than an exact protocol. The "default" is effectively "SSL 3.0 or higher".

TlsPinSet

TlsPinSet As Character

Introduced in version 9.5.0.55

Specifies a set of pins for Public Key Pinning for TLS connections. This property lists the expected SPKI fingerprints for the server certificates. If the server's certificate (sent during the TLS handshake) does not match any of the SPKI fingerprints, then the TLS handshake is aborted and the connection fails. The format of this string property is as follows:

hash_algorithm, encoding, SPKI_fingerprint_1, SPKI_fingerprint_2, ...

For example, the following string specifies a single sha256 base64-encoded SPKI fingerprint:

"sha256, base64, lKg1SIqyhPSK19tlPbjl8s02yChsVTDklQpkMCHvsTE="

This example specifies two SPKI fingerprints:

"sha256, base64, 4t37LpnGmrMEAG8HEz9yIrnvJV2euVRwCLb9EH5WZyI=, 68b0G5iqMvWVWvUCjMuhLEyekM5729PadtnU5tdXZKs="

Any of the following hash algorithms are allowed:.sha1, sha256, sha384, sha512, md2, md5, haval, ripemd128, ripemd160,ripemd256, or ripemd320.

The following encodings are allowed: base64, hex, and any of the encodings indicated in the link below.

More Information and Examples

Encodings Supported by Chilkat

TotalUploadSize

TotalUploadSize As Numeric (read-only)

The total size of the upload (in bytes). This property will become set at the beginning of an asynchronous upload. A program may monitor asynchronous uploads by tracking both NumBytesSent and PercentUploaded.

This property is also set during synchronous uploads.

UploadInProgress

UploadInProgress As Boolean (read-only)

Set to .T. when an asynchronous upload is started. When the asynchronous upload is complete, this property becomes equal to .F.. A program will typically begin an asynchronous upload by calling BeginUpload, and then periodically checking the value of this property to determine when the upload is complete.

UploadSuccess

UploadSuccess As Boolean (read-only)

Set to .T. (success) or .F. (failed) after an asynchronous upload completes or aborts due to failure. When a program does an asynchronous upload, it will wait until UploadInProgress becomes .F.. It will then check the value of this property to determine if the upload was successful or not.

VerboseLogging

VerboseLogging As Boolean

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

Version

Version As Character (read-only)

Version of the component/library, such as "9.5.0.94"

More Information and Examples

How to get the Chilkat version at runtime.

Methods

AbortUpload

AbortUpload()

May be called during an asynchronous upload to abort.

AddCustomHeader

AddCustomHeader(name As Character, value As Character)

Adds a custom HTTP header to the HTTP upload.

AddFileReference

AddFileReference(name As Character, filename As Character)

Adds a file to the list of files to be uploaded in the next call to BlockingUpload, BeginUpload, or UploadToMemory. To upload more than one file, call this method once for each file to be uploaded.

AddParam

AddParam(name As Character, value As Character)

Adds a custom HTTP request parameter to the upload.

BeginUpload

BeginUpload() As Boolean

Starts an asynchronous upload. Only one asynchronous upload may be in progress at a time. To achieve multiple asynchronous uploads, use multiple instances of the Chilkat Upload object. Each object instance is capable of managing a single asynchronous upload.

When this method is called, a background thread is started and the asynchronous upload runs in the background. The upload may be aborted at any time by calling AbortUpload. The upload is completed (or failed) when UploadInProgress becomes .F.. At that point, the UploadSuccess property may be checked to determine success (.T.) or failure (.F.).

Returns .T. for success, .F. for failure.

More Information and Examples

Debugging HTTP Upload Asynchronous HTTPS Upload Example

BlockingUpload

BlockingUpload() As Boolean

Uploads files to a web server using HTTP. The files to be uploaded are indicated by calling AddFileReference once for each file (prior to calling this method).

Returns .T. for success, .F. for failure.

More Information and Examples

Debugging HTTP Upload IIS 7.0 Upload Size Limitations IIS 6.0 Upload Size Limitations BlockingUpload Example

BlockingUploadAsync ⁽¹⁾

BlockingUploadAsync() As CkTask

Creates an asynchronous task to call the BlockingUpload method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns .F. on failure

ClearFileReferences

ClearFileReferences()

Clears the internal list of files created by calls to AddFileReference.

ClearParams

ClearParams()

Clears the internal list of params created by calls to AddParam.

LoadTaskCaller

LoadTaskCaller(task As CkTask) As Boolean

Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns .T. for success, .F. for failure.

SleepMs

SleepMs(millisec As Numeric)

A convenience method for putting the calling process to sleep for N milliseconds. It is provided here because some programming languages do not provide this capability, and sleeping for short increments of time is helpful when doing asynchronous uploads.