CMC_message
A CMC_message
structure contains information about a CMC message.
Quick Info
|
Header
file: |
XCMC.H |
typedef struct {
CMC_message_reference
*message_reference;
CMC_string message_type;
CMC_string subject;
CMC_time time_sent;
CMC_string text_note;
CMC_recipient *recipients;
CMC_attachment *attachments;
CMC_flags
message_flags;
CMC_extension *message_extensions;
} CMC_message;
Members
message_reference
Pointer to
the message reference, which is a counted string (that is, a CMC_counted_string
structure). The message reference is a unique identifier for a message
within a mailbox.
message_type
Pointer to a
string that identifies the type of the message. Three different string
identifiers are available:
Object identifiers, which are used for
message types identified by object identifiers as defined in CCITT
Recommendation X.208.
CMC registered values, which are used for
message types defined in the CMC specification.
Bilaterally defined values, which are used
for message types that are unregistered. CMC does not ensure that bilaterally
defined values are unique.
For the
complete specification of CMC message types, see Remarks.
subject
Pointer to a
string describing the subject of the message.
time_sent
The CMC_time structure containing the
date and time when the client application submits the message to the CMC
implementation.
text_note
Pointer to
the string containing the message text. If the value of this member is NULL,
there is no message text. If the CMC_MSG_TEXT_NOTE_AS_FILE flag is set for the message_flags
member, the message text is in the first attachment to the message. For
information on message text format, see Remarks.
recipients
Pointer to
the first element in an array of CMC_recipientHLUJFI structures defining the message
recipients.
attachments
Pointer to
the first element in an array of CMC_attachment structures defining the
attachments to the message.
message_flags
Bitmask of
message flags. The following flags can be set:
CMC_MSG_LAST_ELEMENT
The last
element in an array of CMC_message structures. The structure with this flag set
must be at the end of the array. If this flag is set to zero for any structure,
that structure is not the last array element.
CMC_MSG_READ
The message
has been read. If this flag is set to zero, the message has not been read.
CMC_MSG_TEXT_NOTE_AS_FILE
The text_note
member is ignored and the message text is contained in the file referred to by
the first attachment. If this flag is set to zero, the message text is
contained in the text_note member.
CMC_MSG_UNSENT
The client
application has not sent the message, for example when the message is a draft.
The sender can create such a message with the CMC_X_COM_SAVE_MESSAGE data
extension. If this flag is set to zero, the client application has sent the
message.
message_extensions
Pointer to
the first structure in an array of CMC_extension structures representing the
message extensions.
Remarks
Message types
are used to distinguish between various sorts of messages that might require
different processing. For example, the message type might be used by the client
application to determine how to display the message or by CMC to determine how
to send the message.
CMC message
types possible in the message_type member of a CMC_message structure can have the
following formats and are case-insensitive.
"OID: " + object_identifier
"CMC: " + cmc_registered_value
"BLT: " + string
An
object_identifier is a string containing a series of whitespace separated
integers. See CMC_object_identifier for details.
The following
is a list of message types
IPM
Interpersonal
message. An interpersonal message is a memo-like message containing a recipient
list, an optional subject, an optional text note, and zero or more attachments.
The CMC_message structure is optimized to accommodate a message with the
registered value IPM.
IP RN
Read
notification for an interpersonal message. A read notification indicates the
recipient has opened a message.
IP
NRN
Nonread
notification for an interpersonal message. A nonread notification indicates a
message has been removed from the recipient s mailbox without being opened. For
instance, the service or user has discarded the message or it has been
automatically forwarded to another recipient.
DR
Delivery
report. A delivery report indicates the service was able to deliver a message
to its recipient.
NDR
Nondelivery
report. A nondelivery report indicates the message service was not able to
deliver a message to its recipient.
Bilaterally
defined values are arbitrary strings and are used to identify custom message
types used by the client application.
As the syntax
preceding indicates, the OID: type identifier indicates a type identified by an
object identifier, the CMC: type identifier indicates a type identified by a CMC
registered value, and the BLT: type identifier
indicates a type identified by a bilaterally defined value. Following are
examples of valid type identifiers:
OID: 1 2 840 113556 3 2 850
CMC: IPM
BLT: my special message type
You can
format type identifiers as you choose; the CMC implementation also defines a
canonical type identifier format that allows a client application to easily
compare type identifier strings. The CMC implementation always returns type
identifiers in this format, which guarantees the following:
All tokens are separated with a
single space.
The type identifiers OID:, CMC:, and BLT: are returned in uppercase.
The CMC
specification does not define what it will do with type identifier strings that
are not in this format.
The formats
of messages with the preceding registered values within a CMC_message structure depend on the
messaging protocols employed by the underlying messaging system. Often, non-IPM
messages take the form of a program-generated message, which follows a
memo-like format similar to an IPM format but serves instead to convey
information about a previously sent message.
Note The
cmc_registered_value types correspond to X.400 message types; however,
non-X.400 messaging systems can also use them. Thus, these message types are meant
to apply generically and not specifically to X.400 services.
Some
implementations only support the interpersonal message type (CMC: IPM). Some
implementations might treat messages of types other than IPM as IPM messages or
might generate an error for such messages.
For the text_note
member, the format of the message text is a sequence of paragraphs, whether it
is passed in memory or in a file. Each paragraph is terminated with the
appropriate line terminator for the platform: CR (carriage return) for Macintosh,
LF (linefeed) for UNIX, and CR/LF for MS-DOS and Windows. The CMC
implementation can word-wrap long lines (paragraphs). There is no guarantee
that paragraph formatting will remain constant when a message is saved and read
back. For example, the cmc_read function can return a long paragraph as
a series of shorter paragraphs.
See Also