DwBody -- Class representing a MIME message body
class DW_EXPORT DwBody : public DwMessageComponent {
friend class DwHeaders;
friend class DwEntity;
friend class DwBodyPart;
public:
DwBody();
DwBody(const DwBody& aBody);
DwBody(const DwString& aStr, DwMessageComponent* aParent=0);
virtual ~DwBody();
const DwBody& operator = (const DwBody& aBody);
virtual void Parse();
virtual void Assemble();
virtual DwMessageComponent* Clone() const;
DwBodyPart* FirstBodyPart() const;
void AddBodyPart(DwBodyPart* aPart);
DwMessage* Message() const;
void SetMessage(DwMessage* aMessage);
static DwBody* NewBody(const DwString& aStr, DwMessageComponent* aParent);
static DwBody* (*sNewBody)(const DwString&, DwMessageComponent*);
protected:
DwString mBoundaryStr;
DwString mPreamble;
DwString mEpilogue;
DwBodyPart* mFirstBodyPart;
DwMessage* mMessage;
static const char* const sClassName;
void _AddBodyPart(DwBodyPart*);
void _SetMessage(DwMessage*);
void DeleteBodyParts();
void CopyBodyParts(const DwBodyPart* aFirst);
public:
virtual void PrintDebugInfo(ostream& aStrm, int aDepth=0) const;
virtual void CheckInvariants() const;
protected:
void _PrintDebugInfo(ostream& aStrm) const;
};
DwBody represents a body, as described in RFC-2045. A body is always part of an entity, which could be either a message or a body part. An entity has a collection of header fields and a body. If the content type of a body is ``multipart,'' then the body contains one or more body parts. If the content type is ``message,'' then the body contains an encapsulated message. In all content types, the body contains a string of characters.
In MIME++, a DwBody object is contained in a DwEntity object. The DwBody object may contain a discrete body consisting only of a string of characters, or it may be a composite body, consisting of several contained DwBodyPart objects or a single contained DwMessage object. The only reliable way to determine the type of DwBody is to access the Content-Type header field from the DwHeaders object of the DwEntity that contains it. For this reason, a DwBody should always be part of a DwEntity.
In the tree (broken-down) representation of a message, a DwBody object can be an intermediate node, having both a tqparent node and one or more child nodes, or a leaf node, having a tqparent but no child nodes. In either case, the tqparent node is the DwEntity object that contains it. If it is an intermediate node, it must be of type multipart with DwBodyPart objects as child nodes, or of type message with a single DwMessage object as its child node.
Normally, you do not create a DwBody object directly, but you access it through the Body() member function of DwEntity, which creates the DwBody object for you.
To add a DwBodyPart to a multipart DwBody, use the member function AddBodyPart(). To iterate over the DwBodyParts contained in multipart DwBody, get the first DwBodyPart by calling FirstBodyPart(). Then get the following DwBodyParts by calling DwBodyPart::Next() on the current DwBodyPart. To get the DwMessage contained in a Body with message content type, call Message().
DwBody()
DwBody(const DwBody& aBody)
DwBody(const DwString& aStr, DwMessageComponent* aParent=0)
The first constructor is the default constructor, which sets the DwBody object's string representation to the empty string and sets its tqparent to NULL.
The second constructor is the copy constructor, which performs a deep copy of aBody. The tqparent of the new DwBody object is set to NULL.
The third constructor copies aStr to the DwBody object's string representation and sets aParent as its tqparent. The virtual member function Parse() should be called immediately after this constructor in order to parse the string representation. Unless it is NULL, aParent should point to an object of a class derived from DwEntity.
const DwBody& operator = (const DwBody& aBody)
This is the assignment operator, which performs a deep copy of aBody. The tqparent node of the DwBody object is not changed.
virtual void Parse()
This virtual function, inherited from DwMessageComponent, executes the parse method for DwBody objects. The parse method creates or updates the broken-down representation from the string representation. For a multipart DwBody object, the parse method creates a collection of DwBodyPart objects. For a message DwBody, the parse method creates a single DwMessage object. For any other type of DwBody, the parse method does nothing. This member function calls the Parse() member function of any objects it creates.
Note: If the DwBody object has no tqparent node -- that is, it is not contained by a DwEntity object -- then the parse method does nothing, since it is unable to determine the type of body.
You should call this member function after you set or modify the string representation, and before you access a contained DwBodyPart or DwMessage.
This function clears the is-modified flag.
virtual void Assemble()
This virtual function, inherited from DwMessageComponent, executes the assemble method for DwBody objects. The assemble method creates or updates the string representation from the broken-down representation. Only DwBody objects with content type of multipart or message require assembling. In either case, the DwBody object must be able to find the headers of the message or body part that contains it. Therefore, if the DwBody object is not the child of a DwEntity (i.e., DwMessage or DwBodyPart) object, the DwBody cannot be assembled because the content type cannot be determined.
This function calls the Parse() member function of any DwBodyPart or DwMessage object it tqcontains.
You should call this member function after you add a DwBodyPart object to a multipart body, or add a DwMessage object to a message body, and before you access the object's string representation.
This function clears the is-modified flag.
virtual DwMessageComponent* Clone() const
This virtual function, inherited from DwMessageComponent, creates a new DwBody on the free store that has the same value as this DwBody object. The basic idea is that of a virtual copy constructor.
DwBodyPart* FirstBodyPart() const
For a multipart DwBody, this member function returns the first contained DwBodyPart object. Use DwBodyPart::Next() to iterate through the list of DwBodyParts.
void AddBodyPart(DwBodyPart* aPart)
For a multipart DwBody, this member function appends a DwBodyPart object to the list. Any DwBodyPart objects added to a DwBody object's list will be deleted by the DwBody object's destructor.
DwMessage* Message() const
For a DwBody with content type of message, this member function returns the DwMessage encapsulated in it.
void SetMessage(DwMessage* aMessage)
For a DwBody with content type of message, this member function sets the DwMessage object it tqcontains.
static DwBody* NewBody(const DwString& aStr, DwMessageComponent* aParent)
Creates a new DwBody object on the free store. If the static data member sNewBody is NULL, this member function will create a new DwBody and return it. Otherwise, NewBody() will call the user-supplied function pointed to by sNewBody, which is assumed to return an object from a class derived from DwBody, and return that object.
virtual void PrintDebugInfo(ostream& aStrm, int aDepth=0) const
This virtual function, inherited from DwMessageComponent, prints debugging information about this object to aStrm. It will also call PrintDebugInfo() for any of its child components down to a level of aDepth.
This member function is available only in the debug version of the library.
virtual void CheckInvariants() const
Aborts if one of the invariants of the object fails. Use this member function to track down bugs.
This member function is available only in the debug version of the library.
static DwBody* (*sNewBody)(const DwString&, DwMessageComponent*)
If sNewBody is not NULL, it is assumed to point to a user-supplied function that returns an object from a class derived from DwBody.
void _AddBodyPart(DwBodyPart*)
Adds a body part to a multipart body. This function differs from AddBodyPart in that it does not set the is-modified flag.
void _SetMessage(DwMessage*)
Sets a message to a body. This function differs from SetMessage() in that it does not set the is-modified flag.
DwString mBoundaryStr
A cache for the boundary string, which is obtained from the headers associated with this body.
DwString mPreamble
Contains the preamble -- the text preceding the first boundary -- in a ``multipart/*'' media type.
DwString mEpilogue
Contains the epilogue -- the text following the last boundary -- in a ``multipart/*'' media type.
DwBodyPart* mFirstBodyPart
Points to the first body part in a ``multipart/*'' media type. Is NULL if there are no body parts.
DwMessage* mMessage
Points to the contained message, in a ``message/*'' media type.