NetCode Class

Properties   Methods   Events   Config Settings   Errors  

The NetCode class 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

class ipworks.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 decoded_data property and the encoded data or filename is specified by the encoded_data property. The file_name property may be used to override the default file names or to specify a directory during uuencoding. After uudecoding, the file_name 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 encoded_data 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 encoded_data.

Property List

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

decoded_data Property

This property includes the decoded data.

Syntax

def get_decoded_data() -> bytes: ...
def set_decoded_data(value: bytes) -> None: ...

decoded_data = property(get_decoded_data, set_decoded_data)

Default Value

""

Remarks

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

decoded_file Property

This property includes the filename of the decoded data.

Syntax

def get_decoded_file() -> str: ...
def set_decoded_file(value: str) -> None: ...

decoded_file = property(get_decoded_file, set_decoded_file)

Default Value

""

Remarks

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

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

encoded_data Property

This property includes the encoded data.

Syntax

def get_encoded_data() -> bytes: ...
def set_encoded_data(value: bytes) -> None: ...

encoded_data = property(get_encoded_data, set_encoded_data)

Default Value

""

Remarks

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

encoded_file Property

This property includes the filename of the encoded data.

Syntax

def get_encoded_file() -> str: ...
def set_encoded_file(value: str) -> None: ...

encoded_file = property(get_encoded_file, set_encoded_file)

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 encoded_file 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 encoded_file in the form name???. Question marks "?" are expanded to numerals starting with 000 (the number of zeros "0" equals that of question marks "?").

The class appends the extension ".uue", ".b16", or ".q_p" depending on format immediately after the generated numbers. file_cnt contains the number of encoded files.

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

file_cnt Property

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

Syntax

def get_file_cnt() -> int: ...

file_cnt = property(get_file_cnt, None)

Default Value

0

Remarks

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

Please refer to encoded_file for filename conventions.

This property is read-only.

file_name Property

This property includes the destination filename for the encoded data.

Syntax

def get_file_name() -> str: ...
def set_file_name(value: str) -> None: ...

file_name = property(get_file_name, set_file_name)

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 class 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 file_name.

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.

format Property

This property includes the type of encoding to be used.

Syntax

def get_format() -> int: ...
def set_format(value: int) -> None: ...

format = property(get_format, set_format)

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:

mode Property

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

Syntax

def get_mode() -> str: ...
def set_mode(value: str) -> None: ...

mode = property(get_mode, set_mode)

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.

overwrite Property

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

Syntax

def get_overwrite() -> bool: ...
def set_overwrite(value: bool) -> None: ...

overwrite = property(get_overwrite, set_overwrite)

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.

progress_step Property

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

Syntax

def get_progress_step() -> int: ...
def set_progress_step(value: int) -> None: ...

progress_step = property(get_progress_step, set_progress_step)

Default Value

1

Remarks

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

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

config Method

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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

This method decodes a string.

Syntax

def decode() -> None: ...

Remarks

This method decodes according to the format type. The class will decode the data in the input stream if set_input_stream has been set to a valid stream. If this stream is null, the class will then try to read the data from the file set by the encoded_file property. If no valid file has been specified, the class will use the encoded_data 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 decoded_file. If no file was specified, the decoded data may be retrieved through the decoded_data property.

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

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

encode Method

This method encodes the data.

Syntax

def encode() -> None: ...

Remarks

This method encodes the data according to the format type. The class will encode the data in the input stream if set_input_stream has been set to a valid stream. If this stream is null, the class will then try to read the data from the file set by the decoded_file property. If no valid file has been specified, the class will use the decoded_data 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 encoded_file. If no file was specified, the encoded data may be retrieved through the encoded_data 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 file_name 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 encoded_file 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 encoded_file 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

This method will reset the class.

Syntax

def reset() -> None: ...

Remarks

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

reset_data Method

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

Syntax

def reset_data() -> None: ...

Remarks

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

on_error Event

Fired when information is available about errors during data delivery.

Syntax

class NetCodeErrorEventParams(object):
  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class NetCode:
@property
def on_error() -> Callable[[NetCodeErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[NetCodeErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally the class 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.

on_progress Event

This event occurs when PercentDone of the input is read.

Syntax

class NetCodeProgressEventParams(object):
  @property
  def percent_done() -> int: ...

# In class NetCode:
@property
def on_progress() -> Callable[[NetCodeProgressEventParams], None]: ...
@on_progress.setter
def on_progress(event_hook: Callable[[NetCodeProgressEventParams], None]) -> None: ...

Remarks

The progress_step property determines how often the event is fired.

NetCode Config Settings

The class 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 class, access to these internal properties is provided through the config method.

NetCode Config Settings

Base Config Settings

NetCode Errors

NetCode Errors