ATL / WTL / STL

<code>#define		DB_ERROR		1
#define		DB_EXCEPTION	2

class DBItem;

typedef pair<string, string>	ssPair;
typedef vector<DBItem*>		DBIList;

struct DataStructure
{
	map<string, _variant_t> mAttr;
	map<string, BOOL> mAttrLoaded;
	map<string, BOOL> mAttrModified;
	map<string, string> mAttrFields;// field, attr name;
	map<string, string> mLinks;// attr, link class
	map<string, ssPair> mDeps; // depends
	string sIdField;
	string sTableName;
	string sTittleAttr;
	string sTreeLink;
};

class DBItem  
{
public:
	DBItem(int nId, _ConnectionPtr  pConnectionGeneral = NULL);
	virtual ~DBItem();

	_variant_t GetAttr(string sAttr);
	string GetName();
	DBItem *GetObject(string sAttr);
	DBIList *GetInstances();
	virtual string GetClass();

protected:
	DBItem *GetInstance(string sClassName, unsigned long nId);
	DataStructure ds;

private:
	_ConnectionPtr  pConnDB;
	_RecordsetPtr pRstDB;
	int nIid;
	stack<string> mMessages;
	BOOL bNoLogging;

	BOOL Load();
	void FormLoadQuery(char **szQuery);
	void FormGetIDsQuery(char **szQuery);
	BOOL ExecuteQuery(string sQuery);
	void AddMessage(int nMsgType, string sMessage);
	string ToString(int nConvertable);
	string ToString(long nConvertable);
};</code>

<code>#include "stdafx.h"
#include "DB_Obj1.h"

DB_Obj1::DB_Obj1(int nId, _ConnectionPtr  pConnectionGeneral) : DBItem(nId, pConnectionGeneral)
{
	_variant_t	vtNull;
	vtNull.vt = VT_NULL;

	// Init attributes as NULL (the variant way)
	ds.mAttr["Id"] = vtNull;
	ds.mAttr["Name"] = vtNull;
	ds.mAttr["State"] = vtNull;

	// Set Table Field <=> Attribute correspondence
	ds.mAttrFields["IdObj"] = "Id";
	ds.mAttrFields["ObjName"] = "Name";
	ds.mAttrFields["CurrentState"] = "State";

	// Init attributes as not load and not modified
	// TODO: Implement uses for this :D
	ds.mAttrLoaded["Id"] = 
	ds.mAttrLoaded["Name"] =
	ds.mAttrLoaded["State"] = 
	ds.mAttrModified["Id"] = 
	ds.mAttrModified["Name"] =
	ds.mAttrModified["State"] = FALSE;

	// Set internal links to other Item Types, as in attributes that represent another object, via an ID
	ds.mLinks["State"] = "DB_StateObj";

	// Set dependencies. What other object types link to me basicly. Should support dependency types
	// and enforcing them on deletes, inserts
	ds.mDeps["someone_depends_on_me_somehow"] = make_pair((string)"DB_SomeObj", (string)"IdObj1");

	// Set various other data
	ds.sIdField = "IdObj";
	ds.sTableName = "objects1";
	ds.sTittleAttr = "Name";
	ds.sTreeLink = "";
}

DB_Obj1::~DB_Obj1()
{

}

string DB_Obj1::GetClass()
{
	return (string)"DB_Obj1";
}</code>

Mustafa Ismail Mustafa wrote:

would I have to actually split the string manually by looping through the character array

        try
{
    //add the empty set phi first
    ListOfSubsets().push_back("{}");

    //create the iterator
    list<char*>::iterator pos;

    //add the set of elements singly
    for(pos = ListOfElements().begin(); pos != ListOfElements().end(); ++pos)
    {
        cout << *pos << endl;
    }
}
catch(exception ex)
{
    cout << "an error has occurred: " << endl;
    cout << ex.what() << endl;

    return;
}

private:
	list<char*> _ListOfElements;
	list<char*> _ListOfSubsets;
	
protected:
	//getter & setter function

	//ListOfElements
	list<char*> ListOfElements(void) const	//constant function [Read only]
	{
		return _ListOfElements;
	}
	void set_ListOfElements(list<char*> listOfElements)
	{
		_ListOfElements = listOfElements;
	}


	//ListOfSubsets
	list<char*> ListOfSubsets(void) const
	{
		return _ListOfSubsets;
	}
	void set_ListOfSubsets(list<char*> listOfSubsets)
	{
		_ListOfSubsets = listOfSubsets;
	}

Use of two sequential underscore characters ( __ ) at the beginning of an identifier, or a single leading underscore followed by a capital letter, is reserved for C++ implementations in all scopes. You should avoid using one leading underscore followed by a lowercase letter for names with file scope because of possible conflicts with current or future reserved identifiers.

Florin Crisan wrote:

const list & ListOfElements(void) const

list ListOfElements(void) const

Mustafa Ismail Mustafa wrote:

But I still don't understand, why a reference has to be returned?

Like here:

Florin Crisan wrote:
const list & ListOfElements(void) const



instead of a plain

list ListOfElements(void) const

?