Node Class

Abstract base class for all classes representing message components.

For a list of all members of this type, see Node Members.

System.Object
   Node

Remarks

Node is the root of an inheritance hierarchy that includes many classes in MIME.NET. All classes that represent MIME document components are subclasses of Node. The Node class defines important features that are inherited by these subclasses. These features are the following:

• A string representation. The string representation is the serialized representation of a MIME document component. The Node class provides a property String to get or set the string representation.

• A broken-down representation. The broken-down representation is the parsed representation of a MIME document component. For example, the broken-down representation of an RFC 2822 date-time consists of the year, month, day, hour, minute, second, and time zone. Subclasses of Node provide properties or methods to set or get elements of the broken-down representation.

• A parse operation to create or update the broken-down representation from the string representation. In the DateTime class, for example, the parse operation parses the year, month, day, hour, minute, second, and time zone from the RFC 2822 date-time string contained in the string representation. Node provides an abstract method Parse() that subclasses override to execute the parse operation.

• An assemble operation to create or update the string representation from the broken-down representation. This is the opposite of the parse operation. In the DateTime class, for example, the assemble operation creates an RFC 2822 date-time string from values of the year, month, day, hour, minute, second, and time zone. Node provides an abstract method Assemble() that subclasses override to execute the assemble operation.

• An is-modified flag. When the string representation and the broken-down representation are consistent, the assemble operation does not need to be executed. The is-modified flag indicates if the string representation and the broken-down representation are consistent. The flag is cleared when the two representations are consistent, and is set when they are inconsistent. The flag is set when a Node object's broken-down representation is changed by calling one of its methods. It is cleared when the assemble or parse operation is executed. Node also provides a property Modified that gets or sets the is-modified flag.

  Normally, you can ignore the is-modified flag. The Assemble() method always checks the is-modified flag and returns immediately if the flag is cleared. The library uses the is-modified flag to optimize the Assemble() method.

• A parent node. MIME.NET maintains a tree structure of Node objects. The parent-child relationship among Node objects parallels the superstring-substring relationship among the "components" of a MIME document. For example, where a MIME message contains substrings for the headers and the body, MIME.NET provides a Message node object that has a Headers child node and a Body child node. Where a MIME headers string contains a substring for each header field, MIME.NET provides a Headers node object that has a collection of Field child nodes.

  To maintain consistency in the tree, whenever a node's is-modified flag is set, the node requests its parent to also set its is-modified flag. In this way, an is-modified flag set anywhere in the tree always propagates to the root node.

• Child nodes. Subclasses of Node provide methods to access their child nodes. A node's parse operation invokes the parse operations of its child nodes after it has updated its broken-down representation. Also, a node's assemble operation invokes the assemble operations of its child nodes before it updates its string representation.

Requirements

Namespace: Hunny.Mime

Assembly: Hunny.Mime (in Hunny.Mime.dll)

See Also

Node Members | Hunny.Mime Namespace