How To Handle An Open Document

First off I am still a noob so be nice :)

I have an MFC program created from the app wizard. It is an MDI program, reading/writing text files using Serialize. I can read the document and know that the entire document was read into my buffer without any errors. This was verified by compaing the number of bytes read with the file length.

How do I get the document to display in my main/child window?

How do I read the document from the window so I can save it back to the file?

Sample lines of code would be great!!

Thanks in advance :thumb: for answering simple questions from a confused old fart ;)

John

1. You display the document data neither in main nor in child window. You display it in one or more Views. And it is up to you to choose the types of the Views to display the document data.
2. If some data displayed in a View was changed then you can use CView::GetDocument method to access the document and change the corresponding data in it.
3. Save document data is just opposed to get it. If you use some type or ReadFile to read - then use corresponding WriteFile to write/save.
   If you use CArchive class to read data (using operator <<()) then use operator >>() to save...
4. Document/View Architecture

Hi Victor,

Thanks for the information and the link.

Since the document is not showing up in my window, what must I do to display it after reading it into memory? I have seen commands like UpdateAll() or UpdateView() (I think) but what must I do once the document is in memory. My window just remains blank.

Thanks again!

John

It is usually UpdateAllViews. Then in each View you have to implement (override) OnUpdate method that will be called in respond on the UpdateAllViews.
In OnUpdate implemetation you put some code to update current View using document data (via GetDocument method).
Have a look at the Scribble Sample: MDI Drawing Application and MDIDOCVW Sample: Demonstrates MDI Using Doc/View Architecture

If your view is derived from CView, you'll need to handle all the text rendering yourself, which would be a pain. A better idea would be to derive your view from CEditView and it should do everything for you.

I am using the CEditView for my view class.

Where do I place the UpdateAllViews() code? Is it right after I open and read my file? Here is my code where I read the file:

Code:

---

void CFoo::ReadFileData(CArchive& ar)
{
        BSTR                                unicodestr;
        char*                                ansistr = new char[0x100];
        CString                                sTempNew = STR_EMPTY;
        CString                                sTempOld = STR_EMPTY;
        DWORD                                nBytesRead = 0;
        UINT                                nr;
        WCHAR                                pb[0x100];
        CParseDataSubRoutines                pParseDataSubRoutines;

        theApp.DoWaitCursor(TRUE);
        while (nBytesRead < dwFileLength) {
                // Read the data from the UNICODE file
                nr = ar.Read( pb, 0x100 );
                unicodestr = (LPWSTR ) pb;
                // Convert the data from UNICODE to ANSI. Use nr/2 because of the UNICODE
                WideCharToMultiByte(CP_ACP, 0, unicodestr, nr/2, ansistr, nr/2, NULL, NULL);
                //        Now move it to string format
                sTempNew = ansistr;
                //        Add the new data to the old data
                sTempNew = sTempOld + sTempNew.Left(nr/2);
                //        Push the data back into the window
                sTempOld = sTempNew;
                //        Show the bytes read
                nBytesRead+= nr;
        }

        //        Strip off the first byte, part of the file ID (0xff) I think...
        sTempNew = sTempNew.Mid(1,sTempNew.GetLength());

        //        Parse the long string of ANSI data into individual strings
        pParseDataSubRoutines.ParseDataIntoIndividualLines(sTempNew);
        delete[] ansistr;
        theApp.DoWaitCursor(FALSE);
}

---

Before I added the read routine, I was able to see my data in the window, line by line, after the file was read be the default MFC read/Serialize reader routine. Maybe I am not reading the file correctly or maybe some how I need to change a default pointer to where my data is stored in memory?

John

UpdateAllViews is used by the document to tell the view that something has changed and gives the view a chance to do whatever it needs to. I've never used the CEditView and you seem to be writing code outside of the Doc/View architecture, so just given that snipped, I can't tell you what's wrong. I can tell you it's best to let MFC do as much of the work as possible.

You seem to read your file in some local variables/objects that go out of scope after your ReadFileData method exits.

Besides, there is no need to:

• create char* ansistr array in the heap, using
  Code:

  ---

  char ansistr[100];

  ---

  is easier and better
• use CWinApp::DoWaitCursor(TRUE)/CWinApp::DoWaitCursor(FALSE); use
  Code:

  ---

  CWaitCursor cw;

  ---

  instead

The code above should have showed CFooDoc::ReadFileData(void). It does reside in my Doc class.

I understand about the Wait cursor, thanks.

So, let's say I just delete the read file function all together. Now when I open a file it would be handled by the default, built in code. From what I am reading, if I use a pDoc->GetDocument() that will pull my file data into a variable which would allow me to manipulate it? Then how would I push it back to the Window as an updated document with changes that were made by other functions?

I know I must be making this harder than it needs to be. I just need to:

1. Open a file and read it into memory. That works by default.
2. How do I access that data directly so I can manipulate it?
3. How do I push those updates back to the screen so I can see them?
4. Then I would use GetDocument() to retrieve the data so it can be Serialized back to the disc.

Coding is a hobby. I learned assembly language as my first language on a 24-bit mainframe (SEL 840) that ran on a Flight Simulator. Then I progressed to a 16-bit Texas Instruments 980 computer, and eventually was able to exchange data between the computers. That seemed easy compared to what I am now trying to teach myself. I learn fast when I have an example that works. I have books, but just can't seem to find the right answer to getting this to work. Been at it for a few weeks now and have learned a lot, just not what I need :)

A specific line or two of code would be very beneficial.

Thanks for the help.

John

I just used the wizard to create a new app with CEditView as the base class. I wrote no code at all. I compiled it, ran it and opened a text file. It displayed it properly. Again, I didn't write a single line of code. The framework did it all.

Yes, I agree with the wizard and that it works. No arguments. But I still don't understand how to manipulate the data.

I have a parse routine created and works on test data. So when I open a file and read it (using the default wizard code), I need to be able to manually manipulate that code. I want to parse it, put it in say 10 different variables, make changes to it and send it back to the screen (all through functions and not direct interface with the users). The idea is I am reading the data, validating it and if it is incorrect, I am making the change, after it has been read, and then updated on the screen to show the change.

I can parse the data using a test file. It works.

Do I use GetDocument() to pull the data down from the window so I can then parse/process it manually? If so, how do I execute that comand? Is it something like:

Code:

---

CDocument* myDoc = pDoc->GetDocument();

---

Then does my data reside in myDoc and I can parse it?

Once my data is parsed, how do Ipush myDoc back into the window so it shows the updated value?

Thanks for your patience ;)
John

Again, I haven't worked with the CEditView, but looking at the documentation, it looks like you'd call GetEditCtrl from the view class to get its edit control, then use the various CEdit or CWnd functions to get and manipulate the text. GetWindowText() would get you all the text in the edit control and put it in a CString. You could do what you want with it from there, then use SetWindowText() to update the edit control with the new text.

It appears in this case, the CEdit control actually maintains the text and the doc is just used to transfer it between the window and the file.

Ah ha, light bulb came on. Will give that a shot. Seems logical and jives with some other stuff I have been reading and trying.

THANKS! :thumb:

John

Quote:

---

Originally Posted by JohnWHagen

Do I use GetDocument() to pull the data down from the window so I can then parse/process it manually? If so, how do I execute that comand? Is it something like:

Code:

---

CDocument* myDoc = pDoc->GetDocument();

---

---

GetDocument() is a method of CView class, not a CDocument one.
It is used to get/set data from/to Document instance to/from View instance.
Document instance itself should not ever try to directly access any View instance.

Quote:

---

Originally Posted by JohnWHagen

Ah ha, light bulb came on. Will give that a shot. Seems logical and jives with some other stuff I have been reading and trying.

THANKS! :thumb:

John

---

Hope it helps, but keep in mind, that's not usually the way Doc/View works. Typically the document does maintain the data and the view renders it. This seems to deviate from the norm somewhat.

Hi Guys,

I am just in a dazed state and can't seem to even figure this out. If possible, could you please just build a simple project from the class wizard, add the GetWindowText() and SetWindowText() code to get the text into a control, send the text back to the screen, and where to put the UpdateAllViews() at? I know you can do it in about 5 mins as you are clearly skilled.

This is really lame on my part but I am at a point of a mental block and am frustrated big time.

As we used to say as kids... Pretty Please?

You could either post it here or send it to my Google email account using my screen name.

For what it is worth, I am 60 years of age and not a student trying to get help on a school project (wish I was that young again). I can send you other files that I have worked on, just not this type ;)

Thanks.

John

Quote:

---

Originally Posted by JohnWHagen

Hi Guys,

I am just in a dazed state and can't seem to even figure this out. If possible, could you please just build a simple project from the class wizard, add the GetWindowText() and SetWindowText() code to get the text into a control, send the text back to the screen, and where to put the UpdateAllViews() at? I know you can do it in about 5 mins as you are clearly skilled.

This is really lame on my part but I am at a point of a mental block and am frustrated big time.

As we used to say as kids... Pretty Please?

You could either post it here or send it to my Google email account using my screen name.

For what it is worth, I am 60 years of age and not a student trying to get help on a school project (wish I was that young again). I can send you other files that I have worked on, just not this type ;)

Thanks.

John

---

I don't believe you need UpdateAllViews in this case. Again, that's used by the document to let the views know that something has changed. Since your document isn't maintaining the data, it isn't appropriate here.

As to where to put the code, that really depends on when you need it.

The basic code will be in your view class and look something like this.

Code:

---

CString strText;
GetEditCtrl()->GetWindowText(strText);
//manipulate your data here
GetEditCtrl()->SetWindowText(strtext);

---

The first place you could get at it would be in your view's OnInitialUpdate function, after the call to the base class. It should work anywhere after that.

I added the OnInitialUpdate function to my main view class. It is being called as the program starts up, but not after I load the file.

That tells me I need to make another call to the OnInitialUpdate() function. I assume this would be called from the Doc class. I tried that but get an error saying the CView class is protected.

How do I make the next call from my Doc class so I can manipulate the data?

Again, thanks!
John

Quote:

---

Originally Posted by JohnWHagen

I added the OnInitialUpdate function to my main view class. It is being called as the program starts up, but not after I load the file.

That tells me I need to make another call to the OnInitialUpdate() function. I assume this would be called from the Doc class. I tried that but get an error saying the CView class is protected.

How do I make the next call from my Doc class so I can manipulate the data?

Again, thanks!
John

---

Try handling OnUpdate in the view class.

Woo Hoo, progress! :thumb::wave:

I added the OnUpdate() to the View class and now it executes. As the program starts it passes through the OnUpdate() function twice. Then when I load the file and use GetWindowText() I can see the file data. Major progress, although it may seem trivial to others.

I added a Doc object and did a SetDocumentText(<string data>) and it is now resident in my Doc class. From there I should be able to do the manipulation I want. Now, to get the Doc class to send it back to the View I will need to make a call from the View to Doc.GetDocumentText() and the have the view SetWindowText(<my new data>). Is this correct?

The only thing I am not sure of is how to force the View class to call the Doc class to get the updated document data. Guess I could set up a Message, send it and have the View class respond to the message.

Does this sound like a reasonable plan? I know how to send/receive AFX_Msgs. Or, is there a better way?

Thanks again!

John

I think you're overly complicating it. In your case, I'd ignore the document completely. The Edit Control seems to be what stores the text and the doc is set up to Serialize in and out of there. As I said, I'd just use Get and Set WindowText in the view class and just use the default doc stuff to handle the file I/I for you.