NetCode Control

Properties   Methods   Events   Config Settings   Errors  

The NetCode control can be used to encode or decode files or strings using a variety of popular encoding formats, such as Base64, UUencode, and URL. UUEncode , MIME's Base64 Quoted-Printable , and URL encoding formats, as well as secure hash functions such as MD5 and SHA1, are currently supported.

Syntax

NetCode

Remarks

The encoding format is specified by the Format property. The binary data, or the name of the file containing binary data, is specified by the DecodedData property and the encoded data or filename is specified by the EncodedData property. The FileName property may be used to override the default file names or to specify a directory during uuencoding. After uudecoding, the FileName property contains the fully specified file name of the decoded file.

Understanding Encoding/Decoding

Most mail systems use only 7 bits to transmit messages. A binary file, such as an archive or a non-plaintext-formatted file produced from a text processor should be first encoded in 7-bit code before email transfer.

Decoding is the inverse process (i.e., creation of the original file from the encoded data). Encoded data are often split over several files because of the size limit placed on the email message. Each message is preceded by information about this splitting, as well as the mail header. NetCode supports this case in both directions:

- During encoding, setting the MaxFileSize configuration setting to the maximum size of a message body instructs NetCode to split the encoded data over several files. Multiple filenames can be specified by using question marks "?" (see the EncodedData property for more information).

- During decoding, the body messages can be saved in separate files named namexxx.ext, where xxx is a numeral starting at 000 and ext is ".uue", ".b16", or ".q_p" according to Format. These multiple filenames should be given to EncodedData.

Property List

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The following is the full list of the properties of the control with short descriptions. Click on the links for further details.

Method List

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The following is the full list of the methods of the control with short descriptions. Click on the links for further details.

Event List

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The following is the full list of the events fired by the control with short descriptions. Click on the links for further details.

Config Settings

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The following is a list of config settings for the control with short descriptions. Click on the links for further details.

DecodedData Property (NetCode Control)

This property includes the decoded data.

Syntax

netcodecontrol.DecodedData[=string]

Default Value

""

Remarks

This property contains the decoded data. When uuencoding, the value of FileName is the filename that will be written in EncodedData. If FileName is empty, an error will be returned.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .DecodedDataB.

This property is not available at design time.

Data Type

Binary String

DecodedFile Property (NetCode Control)

This property includes the filename of the decoded data.

Syntax

netcodecontrol.DecodedFile[=string]

Default Value

""

Remarks

This property contains the filename of the decoded data. When uuencoding, the value of FileName is the filename that will be written in EncodedData. If FileName is empty, the value of the DecodedFile property is taken, if a valid file has been specified. It is recommended that EncodedData contains the full path and that FileName contains only the filename so that no problems occur while uudecoding in a foreign system.

When decoding, the control tries to generate the name for the created file in the following order: DecodedFile, FileName, or when the format is UUEncode, the specified filename in the uuencoded data. If DecodedFile or FileName end with a backslash "\" they are interpreted as directories, and the control will try to create the given filename in this directory. If this is the case, FileName shows the name of the file that was created.

Data Type

String

EncodedData Property (NetCode Control)

This property includes the encoded data.

Syntax

netcodecontrol.EncodedData[=string]

Default Value

""

Remarks

This property contains the data that either have been encoded or are set to be decoded.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .EncodedDataB.

This property is not available at design time.

Data Type

Binary String

EncodedFile Property (NetCode Control)

This property includes the filename of the encoded data.

Syntax

netcodecontrol.EncodedFile[=string]

Default Value

""

Remarks

This property contains the filename of the encoded data. If the encoded data are spread over several files, the filenames are passed to EncodedFile in the form name?. Question marks "?" are expanded to numerals starting with 0. The filenames should exist as path\file000.ext and are passed to EncodedFile in the form name???. Question marks "?" are expanded to numerals starting with 000 (the number of zeros "0" equals that of question marks "?").

The control appends the extension ".uue", ".b16", or ".q_p" depending on Format immediately after the generated numbers. FileCnt contains the number of encoded files.

See also the Format property, and the MaxFileSize configuration setting when working with multiple files.

Data Type

String

FileCnt Property (NetCode Control)

This property shows the number of encoded files the control has read from or written into.

Syntax

netcodecontrol.FileCnt

Default Value

0

Remarks

This property shows the number of encoded files the control has read from or written into. If the user specifies one or more questions marks "?" in EncodedFile, they will be expanded from 000 to FileCnt - 1 (the number of question marks "?" specifies the number of figures).

Please refer to EncodedFile for filename conventions.

This property is read-only.

Data Type

Integer

FileName Property (NetCode Control)

This property includes the destination filename for the encoded data.

Syntax

netcodecontrol.FileName[=string]

Default Value

""

Remarks

This property contains the destination filename for the encoded data. When uuencoding, this property contains the filename that is specified in the uuencoded data.

When decoding, if the value of the property is not empty, it shows the control where to write the decoded data. It can be either the filename or the directory where the file should be written. If is should be written to a directory, it should end with a backslash "\".

After a decode operation, this property contains the filename for the created file. If the file couldn't be created because of an illegal filename, examining this property might provide a hint about the reason of the failure.

This property must be set to "" (empty string) after each decode operation because it contains the full specification of the file.

An error occurs if a uuencoding operation is initiated with an empty FileName.

If you want to first check the uuencoded filename before creating it on disk, you may assign an illegal directory name to this property (always use a closing backslash "\" to denote it as a directory), then trap the error and check the filename appended to this property.

Data Type

String

Format Property (NetCode Control)

This property includes the type of encoding to be used.

Syntax

netcodecontrol.Format[=integer]

Possible Values

fmtUUEncode(0), 
fmtBase64(1), 
fmtQP(2), 
fmtURL(3), 
fmtJIS(4), 
fmtYEncode(5), 
fmtMD5Hash(6), 
fmtSHA1Hash(7), 
fmtHex(8), 
fmtHTML(9), 
fmtHMAC(10), 
fmtUTF8(11), 
fmtUTF7(12), 
fmtBase32(13), 
fmtBase64URL(14), 
fmtSHA256Hash(15), 
fmtPunycode(16)

Default Value

0

Remarks

This property contains the type of encoding to be used. The following are the possible values for this property, and the corresponding descriptions:

Data Type

Integer

Mode Property (NetCode Control)

This property includes the UNIX-style filemode when uuencoding and uudecoding.

Syntax

netcodecontrol.Mode[=string]

Default Value

"0755"

Remarks

This property contains the UNIX-style filemode when uuencoding and uudecoding. The filemode is usually an octal number, such as 755 or 600, which gives the protections of that file. If the file to uudecode is correctly read, then this property contains the protection string given in the uuencoded data.

This is given for compatibility with other systems and is used only when Format is fmtUUE.

Data Type

String

Overwrite Property (NetCode Control)

This property controls whether created file(s) should overwrite already existing file(s).

Syntax

netcodecontrol.Overwrite[=boolean]

Default Value

False

Remarks

This property controls whether created file(s) should overwrite already existing file(s).

Note: More than one file may be created during uuencoding.

Data Type

Boolean

ProgressStep Property (NetCode Control)

This property controls the granularity at which the Progress event is fired. Values are 0-100.

Syntax

netcodecontrol.ProgressStep[=integer]

Default Value

1

Remarks

This property controls the granularity at which the Progress event is fired. Values are 0-100. If this property is not 0, the Progress event will be fired when 0%, n* ProgressStep and 100% of input data are read.

If this property is 0, the Progress event is disabled.

Data Type

Integer

Config Method (NetCode Control)

Sets or retrieves a configuration setting.

Syntax

netcodecontrol.Config ConfigurationString

Remarks

Config is a generic method available in every control. It is used to set and retrieve configuration settings for the control.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Decode Method (NetCode Control)

This method decodes a string.

Syntax

netcodecontrol.Decode 

Remarks

This method decodes according to the Format type. The control will decode the data in the input stream if SetInputStream has been set to a valid stream. If this stream is null, the control will then try to read the data from the file set by the EncodedFile property. If no valid file has been specified, the control will use the EncodedData property.

The resulting decoded data are written to the output stream if one has been set. If not, the component will attempt to write the decoded data to the DecodedFile. If no file was specified, the decoded data may be retrieved through the DecodedData property.

When UUDecoding the created filename will by default be the one specified in the uuencoded data. The FileName property will contain this value. DecodedFile or, if DecodedFile is empty, FileName can be used to override this value.

When YDecoding, the source path and filename is specified in EncodedFile and the destination path and filename in DecodedFile. If the encoded data indicate the name of the original file before decoding, this value will be stored in the FileName property. To decode a multipart message, all parts must be concatenated in order in the source file.

Encode Method (NetCode Control)

This method encodes the data.

Syntax

netcodecontrol.Encode 

Remarks

This method encodes the data according to the Format type. The control will encode the data in the input stream if SetInputStream has been set to a valid stream. If this stream is null, the control will then try to read the data from the file set by the DecodedFile property. If no valid file has been specified, the control will use the DecodedData property.

The resulting encoded data are written to the output stream if one has been set. If not, the component will attempt to write the encoded data to the EncodedFile. If no file was specified, the encoded data may be retrieved through the EncodedData property.

The data are considered binary while uuencoding and Base64 Formats, and text during QuotedPrintable ones.

When uuencoding or yencoding, the filename encoded into the data is taken from the FileName property.

The current version of NetCode does not create message headers. If a MIME standard encoding is used, such as Base64 Encoding or Quoted Printable Encoding, the user should fill the header values appropriately.

If EncodedFile and MaxFileSize is set and the encoded data take more space than MaxFileSize, the data are split over several files. In this case, the user can specify more than one filename by passing them to EncodedFile in the form name?. The filenames should exist as path\file0.ext, path\file1.ext ... Question marks "?" are expanded to numerals starting with 0. NetCode appends the extension ".uue", ".b16", or ".q_p" (depending on the value of Format) to the filename.

Reset Method (NetCode Control)

Reset the control.

Syntax

netcodecontrol.Reset 

Remarks

This method will reset the control's properties to their default values.

ResetData Method (NetCode Control)

This method resets the values of all data and stream properties.

Syntax

netcodecontrol.ResetData 

Remarks

This method resets the values of all data and stream properties. It is an easy way to reset the control's properties before another call to Encode or Decode. The input and output streams and the data and file properties will all be reset.

Error Event (NetCode Control)

Fired when information is available about errors during data delivery.

Syntax

Sub netcodecontrol_Error(ErrorCode As Integer, Description As String)

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the control fails with an error.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Progress Event (NetCode Control)

This event occurs when PercentDone of the input is read.

Syntax

Sub netcodecontrol_Progress(PercentDone As Integer)

Remarks

The ProgressStep property determines how often the event is fired.

Config Settings (NetCode Control)

The control accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these internal properties is provided through the Config method.

NetCode Config Settings

Base Config Settings

Trappable Errors (NetCode Control)

NetCode Errors

	20002    Short uuencoded file.
	20003    The closing 'end' was not found (uudecoded file may be too short).
	20004    Cannot create the file for write (illegal name or disk is write-protected).
	20005    Cannot open the file for read (does not exist?).
	20006    Cannot read from file.
	20007    Cannot write to file (disk full?).
	20008    Please supply a filename for uuencoded data.
	20009    File exists and Overwrite was set to False.
	20010    Space is not sufficient in the output string.
	20011    The given filenames are insufficient to split all the encoded data.
	20012    Please supply a filename for the encoded data.
	20013    Encoded data cannot be written in more than 100 files.
	20014    Could not write to file. Permission denied.
	20015    Could not write to file. Disk full.
	20016    Too many open files. No more file handles are available, so no more files can be opened.
	20017    The given filename does not exist.
	20018    There are no more files to read from or write to.
	20019    The starting 'begin' was not found. Is it uuencoded data?
	20020    The current format is not supported.
	20021    The specified stream does not support Available().
	20022    Format error when YDecoding.
	20023    No '=yend' found when YDecoding.
	20024    Escape character found at end of line when YDecoding.
	20025    CRC check failed when YDecoding (Corrupt data).
	20026    Output buffer length was not calculated.
	20027    Invalid character in Base64 data.