C / C++ / MFC

7-Jan-09 2:28

I have inherited some old code. Our sadistic project management has decided to forbid use of MFC in the hope of being more portable. I replaced all the CStrings with string, now I have got some tricky parts left.
The guy who wrote this used CMapStringToOb in what seems to be a very clever way and I think it is a fine piece of code. But I have to replace it - but with what? I can't use CObjects any more.

I have things like this:
CString csMsgID;
pCommand SACommand; //(which is a CObject)
CMapStringToOb m_knownCommands;
m_knownCommands.Lookup((LPCTSTR)csMsgID, (CObject*&) pCommand)
m_knownCommands.SetAt((LPCTSTR)csMsgID, apFba[i]);

I suppose I could plod through and dream up something complicated and slow, but does anyone have an idea how to do this in an elegant manner? Is this what the type Object is for?

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Bibo ergo sum

CPallini7-Jan-09 2:54

7-Jan-09 2:54

RedSonja wrote:
I have inherited some old code. Our sadistic project management has decided to forbid use of MFC in the hope of being more portable.

I'm definitely not an MFC fan, anyway I think your management deserves a kick in the ass.

Must you be stuck with C language or may you use C++?

With C++, you may use STL containers. If you need to use only C, then I suppose you should search for a library offering hashing functions.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

RedSonja7-Jan-09 2:58

7-Jan-09 2:58

Oh, yes, we can use STL containers. Which do you recommend?

(I am not really lazy, but I do not usually program this high up in the food chain, and my boss wanted it done in December.)

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Bibo ergo sum

Cedric Moonen7-Jan-09 3:04

Cedric Moonen

7-Jan-09 3:04

I guess using a std::map would do the trick. The problem is that you won't be able to use CObject as a base class, but anyway it is quite ugly anyway. If all the objects in your map have the same base class, then it is fine. If your map needs to store different kind of objects, then probably you need to think the design a bit better...

Cédric Moonen
Software developer

Charting control [v1.5]
OpenGL game tutorial in C++

CPallini7-Jan-09 3:09

7-Jan-09 3:09

std::map< std::string, YourRootClass * >

However, as already suggested by Cedric Moonen, maybe better to re-think a bit about the project design (I know it would require experience, time and effort) than mimic the MFC behaviour.

Smile | :)

RedSonja7-Jan-09 3:26

7-Jan-09 3:26

Hmm, you are quite right. Looking at the code a bit harder (I was scared off by CMapStringToOb looking so complicated) I can see he has nothing more than a list of objects derived from the same class, nothing more than that. So I can try with std::list and do the clever bits in a simpler way.

I was hoping to avoid changing every single reference to the things (this is a very large amount of code), but it has to be done, and this week no-one is there to ask what I'm doing. I have redesigned this project quite a lot since it landed on my desk, and this is just about the last untouched corner.

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Bibo ergo sum

Cedric Moonen7-Jan-09 3:32

Cedric Moonen

7-Jan-09 3:32

RedSonja wrote:
I can see he has nothing more than a list of objects derived from the same class, nothing more than that. So I can try with std::list and do the clever bits in a simpler way.

It is a bit more complex than just a list. It is a map which associate each object to a key (being a string). No duplicate key can be found in the map.

To begin working with a std::map, you can look at these tutorials: here[^] or here[^]. You can probably find hundreds of tutorials on the net if you google a bit.

Cédric Moonen
Software developer

Charting control [v1.5]
OpenGL game tutorial in C++

RedSonja7-Jan-09 3:36

7-Jan-09 3:36

Yes, I spotted the key, I need some of those too. Thank you for the tutorials, I shall have a look.

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Bibo ergo sum

XML Writer

amit.code7-Jan-09 1:48

amit.code

7-Jan-09 1:48

Hi.. i want to write xmlwriter function for writing in xml file in c++.Is there any MFC class by which i can implement it or any sample code as reference.
Thanks

amit

Stuart Dootson7-Jan-09 2:02

Stuart Dootson

7-Jan-09 2:02

Don't think MFC has any XML functionality built in.

If you're just writing XML, genx is very easy to use.

Other options include MSXML or libxml2 (which has an XML writer API). I personally don't like MSXML too much for C++, as calling it via COM is a bit of a pain.

CPallini7-Jan-09 2:08

7-Jan-09 2:08

If you need to write some simple XML then you can hand-craft it (writing XML is far simpler than reading -parsing- it). If you need a full-fledged XMLWriter then you may use a library, as suggested by Stuart Dootson.
Smile | :)

Stuart Dootson7-Jan-09 3:32

Stuart Dootson

7-Jan-09 3:32

CPallini wrote:
If you need to write some simple XML then you can hand-craft it

To be honest, I'd always recommend using a writer, as it'll (hopefully) remember to do things like specifying the file's encoding, closing tags, quoting text etc. The quoting text bit, especially, is very easy to forget to do or, even if you remember it, easy to get wrong.

CPallini7-Jan-09 3:49

7-Jan-09 3:49

All do you need then is an XML validator tool. IMHO Writing hand-crafted XML has some educational purposes too.
Smile | :)

amit.code8-Jan-09 18:09

amit.code

8-Jan-09 18:09

Thanks for reply. I have looked for msxml for doing xml operation. I have my parser reader function I need to implement writer function or function to modify existing file. So if I had an xml document and I want to move to specific tag given its ID. Would I have to iterate through all the nodes until I found the tag with the id I wanted or is there a quicker way in msxml. I have read its sdk but fails to find anything regarding this.
Thanks

amit

amit

CPallini8-Jan-09 21:23