Overview

Different transport protocols require different types of attributes; for example, HTTP requires little more than a URL, but FTP requires a username, password, hostname, port, path, and file pattern, and possibly other attributes as well. For this reason, the metadata for HTTP-based and FTP-based TADs are quite different. When a TAD is referenced by a delivery channel, its attributes govern the appearance and behavior of ePM for users who supply values for that channel.

At run time, a TAD’s metadata is made available to the application through the two methods of its associated OTD: unmarshal parses an inbound stream into an internal data structure, and marshal serializes the internal data into a linear outbound stream.

All TADs define their metadata using the format shown in Table 3–1.

Table 3–1 Metadata for All Transport Attribute Definitions

Field Name	Explanation
Name	The (internal) parameter name. Used programmatically; never seen in ePM.
Display	The parameter label as seen by the ePM user.
Type	Data type. Used programmatically; never seen in ePM.
Required	Checkbox governing whether a value must be supplied in ePM. If yes, ePM displays an red asterisk to signal the user that this is a required value.
Direction	FromPartner, ToPartner, or Both. Used programmatically.
Default	The value supplied before the ePM user takes action, or takes no action.
List of Values	Items to display in a drop-down list for the ePM user to choose from
Fixed	(not used in any of presupplied TADs)
Format String	(not used in any of presupplied TADs)