Log Class **advice**

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2 comments, last by KulSeran 13 years, 1 month ago
im wanting to make a class called Log. with the template as follows




class Log

{

private:

std::ofstream outputFile;

SYSTEMTIME systemTimeBuffer;

public:

Log( std::wstring error1 );

Log( std::wstring error1, std::wstring error2 );

Log( std::wstring error1, std::wstring error2, std::wstring error3 );

Log( std::wstring error1, std::wstring error2, std::wstring error3,....... );

.........

........

~ Log();

}




here is my problem...i have a custom exception class with the decleration below

class InvalidArgumentException : public std::exception
{
private:
std::wstring m_message;
std::wstring m_argumentName;
std::wstring m_otherInfo;
public:
InvalidArgumentException( const std::wstring& argumentName );
virtual std::wstring what();
std::wstring getOtherInfo();
};


i have 2 functions that return strings.... what() and getOtherInfo()...obviously i could make my log class except 2 std::wstrings and implement it like that....but then the class MUST EXCEPT 2 strings...what if i or another user wants to use my log class later on and it only has 1 string i need to record info on? say if i or another user wants to use this log class in another program and my/their custom exception returns 3 strings....then they have to edit my class to accomodate for accepting more strings in the constructor. My question is how can i implement it so my log class will except any # of strings and be able to log the info accordingly in a .txt file? is this even possible? i guess im asking is it possible to have a variable number of arguments? or does anyone have any ideas to achieve what im trying to achieve?i dont wanna have to destroy and recreate the object each time i wanna insert a string in my file....plus it will keep printing the time for each time i open then log object! -thx for any advice
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Why not have it accept an STL container of strings?

Log my_error_log;
//...
std::vector<std::string> error_messages;
error_messages.push_back("Great-scott!\n");
error_messages.push_back("There was an error!");
my_error_log.writeToLog(error_messages);


Though it's a bit confusing how the only functions your log prototype there provides are constructors. :huh:
And use code tags, makes stuff easier to read.
There are a lot of approaches, but ultimately it comes down to you deciding what is useful and necessary, providing that, and anyone else just has to conform. You can't please everyone, you'll drive yourself crazy.

Provide the common, expected cases -- 1, 2 or 3 strings, and then provide some kind of back-door to cater to people who might need more -- this might mean writing a version which takes a variable arguments list of strings, or it might simply mean saying "if you want to show more information, you'll have to concatenate some of your strings manually. You are responsible for your own formatting."

Perhaps more to the point, unless you're developing an established library or middleware platform, code for your own use -- this doesn't mean to throw out all thought of what your future needs may be (ie don't choose the easy way and paint yourself into a corner), but it does mean throw out all concerns of what others might need. The simple and blunt fact is that, in all likelihood, no one's going to see, much less use or adapt, your code. Don't make it anything more than you need for your own purposes unless it is being designed explicitly for public consumption (keeping in mind, for example, that "my professor has to grade this" is a form of public consumption). When your code *does* have an audience, understand their needs, don't speculate about them.

throw table_exception("(? ???)? ? ???");

I suggest you look into just overloading operator <<( tType ) so that you can just pipe stuff to you log like you would std::cout, std::cerr, or std::clog.

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