MIME Class

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The MIME class allows for the simple encoding and decoding of MIME structures, such as message attachments and file uploads.

Syntax

class ipworks.MIME

Remarks

The class may be used for decoding or encoding of messages. message holds the content of the encoded message or the filename that holds the encoded data. The decoded data are provided in parts properties.

To decode a MIME message, you should first assign either the whole message (headers and body) to message or put the message headers into the message_headers property and the message body or the filename holding it into the message property. Calling decode_from_file or decode_from_string directs the class to start parsing the message: it will fill out the content_type and content_type_attr properties with message content-type information, and it will enter information about message parts into the parts properties, which includes part sizes, part content types, part content type attributes, part content disposition, part content disposition attributes, part encoding, part name, part filename, part headers, or part content (part-decoded string or part-decoded file) for each decoded part.

Calling the decode_from_string or decode_from_file to decode does not actually decode the message but only parses it. The real decoding is done when the part content in the parts properties is first accessed.

To encode data into a MIME message, you should first assign values for each part to either a part-decoded string or a part- decoded file in the parts properties property, and optionally assign values to the other part attributes in the parts properties. Assigning a value to the part-decoded string or a part-decoded file through the parts properties, fills out automatically the part headers into the parts properties for the respective part. Calling encode_to_file or encode_to_string directs the class to fill out the message with the message body and the message_headers with the headers.

The on_progress event is fired as the message is parsed and the data are decoded/encoded.

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.

boundary Property

This property includes the boundary separating the MIME parts. It has a maximum length of 80 bytes.

Syntax

def get_boundary() -> str: ...
def set_boundary(value: str) -> None: ...

boundary = property(get_boundary, set_boundary)

Default Value

""

Remarks

This property contains the boundary separating the MIME parts and has a maximum length of 80 bytes. The class automatically generates a random boundary value during encoding, if no value is given. During decoding, this property is filled with the boundary from the actual MIME message.

The class will truncate any string longer than 80 bytes if assigned to boundary.

content_type Property

This property includes the value of the content-type header of the message that was encoded/decoded.

Syntax

def get_content_type() -> str: ...
def set_content_type(value: str) -> None: ...

content_type = property(get_content_type, set_content_type)

Default Value

""

Remarks

This property contains the value of the content-type header of the message that was encoded/decoded. The class filters it out from the message_headers. It shows the user information about the type of the parts and their relation to each other.

The content-type attributes, such as filename, boundary, and charset, are held in this property.

content_type_attr Property

This property includes the attributes of the content-type header of the message that was encoded or decoded.

Syntax

def get_content_type_attr() -> str: ...
def set_content_type_attr(value: str) -> None: ...

content_type_attr = property(get_content_type_attr, set_content_type_attr)

Default Value

""

Remarks

This property contains content-type attributes such as "filename", "boundary", and "charset".

message Property

This property contains the encoded message text or a path to a file that contains the encoded message text.

Syntax

def get_message() -> bytes: ...
def set_message(value: bytes) -> None: ...

message = property(get_message, set_message)

Default Value

""

Remarks

This property contains the encoded message text or a path to a file that contains the encoded message text. The class fills out this property with the message body and message_headers during encoding. The user may assign both the headers and the body to this property and leave message_headers empty before decoding.

message_header_count Property

The number of records in the MessageHeader arrays.

Syntax

def get_message_header_count() -> int: ...
def set_message_header_count(value: int) -> None: ...

message_header_count = property(get_message_header_count, set_message_header_count)

Default Value

0

Remarks

This property controls the size of the following arrays:

• message_header_field
• message_header_value

The array indices start at 0 and end at message_header_count - 1.

message_header_field Property

This property contains the name of the HTTP header (this is the same case as it is delivered).

Syntax

def get_message_header_field(message_header_index: int) -> str: ...
def set_message_header_field(message_header_index: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the name of the HTTP Header (this is the same case as it is delivered).

The message_header_index parameter specifies the index of the item in the array. The size of the array is controlled by the message_header_count property.

message_header_value Property

This property contains the header contents.

Syntax

def get_message_header_value(message_header_index: int) -> str: ...
def set_message_header_value(message_header_index: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the Header contents.

The message_header_index parameter specifies the index of the item in the array. The size of the array is controlled by the message_header_count property.

message_headers_string Property

This property includes the string version of the MIME message headers.

Syntax

def get_message_headers_string() -> str: ...
def set_message_headers_string(value: str) -> None: ...

message_headers_string = property(get_message_headers_string, set_message_headers_string)

Default Value

""

Remarks

The component fills out message_headers_string upon encoding. The user should use these strings as additional headers when emailing the message.

This property contains a string version of the MIME message headers. During decoding, if this property is empty, the class will try to find the headers in the beginning of the message and will fill out this property accordingly.

part_count Property

The number of records in the Part arrays.

Syntax

def get_part_count() -> int: ...
def set_part_count(value: int) -> None: ...

part_count = property(get_part_count, set_part_count)

Default Value

0

Remarks

This property controls the size of the following arrays:

• part_content_disposition
• part_content_disposition_attr
• part_content_id
• part_content_type
• part_content_type_attr
• part_decoded_file
• part_decoded_string
• part_encoding
• part_filename
• part_headers
• part_name
• part_size

The array indices start at 0 and end at part_count - 1.

part_content_disposition Property

This property contains content disposition for each part.

Syntax

def get_part_content_disposition(part_idx: int) -> str: ...
def set_part_content_disposition(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains content disposition for each part.

The value in this property is used in the Content-Disposition header. Typical values include "form-data" and "attachment". The class fills it out each time the part_decoded_file is changed. Changing the part_content_disposition recalculates the part_headers as well.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_content_disposition_attr Property

This property contains the content disposition's attribute (if any) for each part.

Syntax

def get_part_content_disposition_attr(part_idx: int) -> str: ...
def set_part_content_disposition_attr(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the content disposition's attribute (if any) for each part.

Typical values for this property are the names of the form-variables used while creating an HTTP post or the values for filenames.

Setting this property recalculates the part_headers.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_content_id Property

This property contains the content identifier for each part.

Syntax

def get_part_content_id(part_idx: int) -> str: ...
def set_part_content_id(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the content identifier for each part. The value of this property is used in the Content-Id header. The class fills it out each time the part_decoded_file is changed. Changing this property recalculates the part_headers as well.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_content_type Property

This property contains the content type for each part.

Syntax

def get_part_content_type(part_idx: int) -> str: ...
def set_part_content_type(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the content type for each part. The value of this property is used in the Content-Type header. Typical values include "image/gif" and "text/plain". The class fills it out each time the part_decoded_file is changed. Changing this property recalculates the part_headers as well.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_content_type_attr Property

This property contains the content-type attribute, if any, for each part.

Syntax

def get_part_content_type_attr(part_idx: int) -> str: ...
def set_part_content_type_attr(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the content-type attribute, if any, for each part. Setting this recalculates the part_headers as well.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_decoded_file Property

This property contains the filename with the decoded data.

Syntax

def get_part_decoded_file(part_idx: int) -> str: ...
def set_part_decoded_file(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the filename with the decoded data. Accessing this property for the first time after calling the decode_from_string or decode_from_file method, directs the class to actually decode the part and save the data in a temporary file. The user is responsible for deleting the temporary file.

Setting a value to part_decoded_file directs the component to calculate the file size and fill out the respective part_size.

Note: It is recommended to use the decode_part_to_file method instead of querying this property.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_decoded_string Property

This property holds the actual content of each part.

Syntax

def get_part_decoded_string(part_idx: int) -> bytes: ...
def set_part_decoded_string(part_idx: int, value: bytes) -> None: ...

Default Value

""

Remarks

This property holds the actual content of each part. The class decodes the actual part of message to part_decoded_string when part_decoded_string's value is first queried.

Setting a value to part_decoded_string fills out the corresponding part_size with the string size if the corresponding part_decoded_file is empty.

The class checks during encoding first part_decoded_file: if it is empty, then the class uses the value of part_decoded_string.

Note: It is recommended to use the decode_part method instead of querying this property.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_encoding Property

This property contains the actual content encoding type for each part.

Syntax

def get_part_encoding(part_idx: int) -> int: ...
def set_part_encoding(part_idx: int, value: int) -> None: ...

Default Value

0

Remarks

This property contains the actual content encoding type for each part. This property determines how to encode the data or how they actually were encoded in the message, as specified in the Content-Transfer-Encoding header.

Possible values for the this property are as follows:

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_filename Property

This property contains the filename attribute specified in the headers of the part.

Syntax

def get_part_filename(part_idx: int) -> str: ...
def set_part_filename(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the filename attribute specified in the headers of the part. Changing the value of the corresponding part_decoded_file automatically sets the part_filename and consequently the part_headers.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_headers Property

This property contains the headers for each MIME part.

Syntax

def get_part_headers(part_idx: int) -> str: ...
def set_part_headers(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the headers for each MIME part. The class fills out this property each time any of the other corresponding part properties are changed. If additional headers are needed, they should be appended after all of the other corresponding part properties are set.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_name Property

This property contains the name given to a part, such as the filename.

Syntax

def get_part_name(part_idx: int) -> str: ...
def set_part_name(part_idx: int, value: str) -> None: ...

Default Value

""

Remarks

This property contains the name given to a part, such as the filename. Changing the value of part_decoded_file automatically sets the corresponding part_name and consequently the part_headers.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

part_size Property

This property contains the size of the DecodedFile or DecodedString .

Syntax

def get_part_size(part_idx: int) -> int: ...

Default Value

0

Remarks

This property contains the size of the part_decoded_file or part_decoded_string. If a non-empty value is assigned to part_decoded_file, then class fills out the corresponding part_size with the file size; if the file does not exist, an error occurs.

If the part_decoded_file is empty and a value is assigned to part_decoded_string, then the corresponding part_size will be equal to the string's size.

During decoding, this property is filled with the size of that part.

The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.

This property is read-only.

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_from_file Method

This method decodes from a file.

Syntax

def decode_from_file() -> None: ...

Remarks

This method decodes the data file given in message and optionally message_headers and fills out the parts properties for each decoded part.

Example. Decoding from a File:

MIMEControl.Message = "C:\filename.txt" MIMEControl.DecodeFromFile

In this example, C:\filename.txt must contain the MIME headers and body. If not, the message_headers property must be set to the appropriate MIME headers.

decode_from_string Method

This method decodes from a string.

Syntax

def decode_from_string() -> None: ...

Remarks

This method decodes from a string. It is the same as DecodeFromFile, but now the message denotes the real encoded message rather than a filename.

This method decodes the data given in message and optionally message_headers and fills out the parts properties.

Example. Decoding a Mail Message:

MIMEControl.MessageHeadersString = MailControl.MessageHeaders MIMEControl.Message = MailControl.MessageText MIMEControl.DecodeFromString

decode_part Method

This method decodes the specified part.

Syntax

def decode_part(index: int) -> bytes: ...

Remarks

This method decodes the part specified by Index and returns the decoded part data.

decode_from_string or decode_from_file must be called before calling this method. Calling this method will return the decoded bytes, and in addition, the part_decoded_string property will be populated with the string representation of the decoded data.

Example. Decoding a Specified Part:mime.MessageHeadersString = myMessageHeaders; mime.Message = myMessageBody; mime.DecodeFromString(); byte[] myPartContent = await mime.DecodePart(0);

decode_part_to_file Method

This method decodes the specified part to a file on disk.

Syntax

def decode_part_to_file(index: int) -> str: ...

Remarks

This method decodes the part specified by Index to a temporary file. The full path to the temporary file is returned by this method. The user is responsible for deleting the temporary file.

decode_from_string or decode_from_file must be called before calling this method.

encode_to_file Method

This method encodes to a file.

Syntax

def encode_to_file() -> None: ...

Remarks

This method encodes the data given in parts properties (either a decoded file or a decoded string) into a MIME message at message and message_headers using the values optionally given in parts properties. To encode several objects into a MIME envelope, the user should first clear any old values left in the parts properties.

The class will check for each item in parts properties (first the decoded file and then the decoded string) for the data to encode.

The encoded message will be saved in the file pointed to by message; the message headers will be held by message_headers.

Example. Encoding Data:

MIMEControl.ResetData() MIMEControl.PartCount = 2 MIMEControl.PartDecodedString(0) = "This is plain text data" MIMEControl.PartEncoding(0) = peQuotedPrintable MIMEControl.PartContentType(0) = "text/plain" MIMEControl.PartDecodedFile(1) = "C:\filename.txt" MIMEControl.Message = "temp.tmp" MIMEControl.EncodeToFile()

encode_to_string Method

This method encodes to a string.

Syntax

def encode_to_string() -> None: ...

Remarks

This method encodes to a string. It is the same as encode_to_file but the encoded data are held in the message property rather than saved to a file.

This method encodes the data given in the parts properties into a MIME message. The message gets stored in message and message_headers using the values optionally given in parts properties. To encode several objects into a MIME envelope, the user should first clear any old values left in the parts properties by calling reset_data.

The class will check each item in the parts properties (first the decoded file and then the decoded string) for the data to encode.

The encoded message will be stored in the message property; the message headers will be held by message_headers.

Example. Encoding Data:

MIMEControl.ResetData() MIMEControl.PartCount = 2 MIMEControl.PartDecodedString(0) = "This is plain text data" MIMEControl.PartEncoding(0) = peQuotedPrintable MIMEControl.PartContentType(0) = "text/plain" MIMEControl.PartDecodedFile(1) = "C:\filename.txt" MIMEControl.EncodeToString()

reset Method

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 headers and part properties.

Syntax

def reset_data() -> None: ...

Remarks

This method resets the values of all headers and part properties. It is an easy way to reset the class's properties before starting to populate the part properties with new values.

on_error Event

Fired when information is available about errors during data delivery.

Syntax

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

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

# In class MIME:
@property
def on_error() -> Callable[[MIMEErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[MIMEErrorEventParams], 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_header Event

This event is fired every time a header is parsed.

Syntax

class MIMEHeaderEventParams(object):
  @property
  def part_index() -> int: ...

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

  @property
  def value() -> bytes: ...

# In class MIME:
@property
def on_header() -> Callable[[MIMEHeaderEventParams], None]: ...
@on_header.setter
def on_header(event_hook: Callable[[MIMEHeaderEventParams], None]) -> None: ...

Remarks

The PartIndex parameter contains the index of the part containing the current header. If the header is from the MIME body, this value will be -1. The Field parameter contains the name of the MIME header. The Value parameter contains the header contents. The on_header event is fired when a header is parsed, which occurs for each header of the message when decode_from_file, decode_from_string, or decode_from_stream is called.

on_progress Event

This event shows the progress of decoding or encoding the input data.

Syntax

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

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

Remarks

The on_progress allows the user to visualize the progress of processing the input data.

The PercentDone parameter shows what percentage of the input has been read.

MIME 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.

MIME Config Settings

Base Config Settings

MIME Errors

MIME Errors

	3   Can't create the file for write (illegal name or disk is write-protected).
	4   Can't open the file for read (doesn't exist?).
	5   Can't read from file.
	6   Can't write to file (disk full?).
	280   Invalid Part Index.
	281   Unknown MIME type.
	282   No MIME-boundary found.
	283   No file given.
	284   The class is busy.
	285   Can't create a temporary file to decode the data.
	286   Can't read message file.
	287   No header separator found.
	289   No separator found.
	290   Input stream must have seeking enabled.