[SOLVED] Checking if a folder is read only in a TShellTreeView

[petevick]

I've cobbeled the following code from google searches, but it doesnt catch known read only folders, it always returns False. Can anyone see what might be wrong.....

Code: Pascal  [Select][+][-]

1. function CheckIfFolderIsReadOnly(SelectedNode: TTreeNode): Boolean;
2. var
3.   FolderPath: String;
4.   FolderInfo: TSearchRec;
5. begin
6.   Result:= True;
7.   // Get the selected node
8. //  SelectedNode := ShellTreeView1.Selected;
9.   if Assigned(SelectedNode) then
10.   begin
11.     // Get the folder path from the selected node
12.     FolderPath := Browser.myTreeView.Path;
13.     // Check if the folder exists
14.     if DirectoryExists(FolderPath) then
15.     begin
16.       // Check if the folder is read-only
17.       if FindFirst(FolderPath, faDirectory, FolderInfo) = 0 then
18.       begin
19.         if (FolderInfo.Attr and faReadOnly) = faReadOnly then
20.          Result:= True
21.         else
22.          Result:= False;;
23.         FindClose(FolderInfo);
24.       end;
25.     end;
26.   end;
27. end;

[KodeZwerg]

Your check is wrong. Here is a correct version:

Code: Pascal  [Select][+][-]

1. uses SysUtils;
2.  
3. function IsDirectoryReadOnly(const DirName: string): Boolean;
4. var
5.  SR: TSearchRec;
6. begin
7.  if FindFirst(DirName, faAnyFile, SR) = 0 then
8.  begin
9.  Result := (SR.Attr and faReadOnly) <> 0;
10.  FindClose(SR);
11.  end
12.  else
13.  Result := False;
14. end;

This here might help but I do not recommend that approach. It checks if its readonly by creating a test file, on success it aint readonly.

Code: Pascal  [Select][+][-]

1. uses SysUtils;
2.  
3. function IsDirectoryReadOnly(const ADirName: string): Boolean;
4. var
5.  TempFile: string;
6. begin
7.  TempFile := IncludeTrailingPathDelimiter(ADirName) + 'tempfile';
8.  try
9.    AssignFile(TempFile);
10.    Rewrite(TempFile);
11.    CloseFile(TempFile);
12.    DeleteFile(TempFile);
13.    Result := False;
14.  except
15.    Result := True;
16.  end;
17. end;

[petevick]

Your check is wrong. Here is a correct version:

Code: Pascal  [Select][+][-]

1. uses SysUtils;
2.  
3. function IsDirectoryReadOnly(const DirName: string): Boolean;
4. var
5.  SR: TSearchRec;
6. begin
7.  if FindFirst(DirName, faAnyFile, SR) = 0 then
8.  begin
9.  Result := (SR.Attr and faReadOnly) <> 0;
10.  FindClose(SR);
11.  end
12.  else
13.  Result := False;
14. end;

Thanks for the help KodeZwerg. I'm getting a little bit closer I think. A problem with my original code was that Browser.myTreeView.Path has a delimiter at the end. The function is now passed Browser.myTreeView.Path and the last delimiter is removed. But it's still not giving consistent correct results, known read only folders are still returning false. The only folder that returns True is the root folder (in Linux) where obviosly the Node.Text value = ''. The FolderInfo.Attr data seems to be ok except I don't know what the Attr = 48; value indicates for a read only folder.
Revised function below based on your code above....

Code: Pascal  [Select][+][-]

1. function CheckIfFolderIsReadOnly(FolderPath: String): Boolean;
2. var
3.   FolderInfo: TSearchRec;
4.   SelectedNode: TTreeNode;
5. begin
6.   // Get the selected node
7.   SelectedNode := Browser.myTreeView.Selected;
8.   if Assigned(SelectedNode) then
9.   begin
10.     // remove last delimiter
11.     LeftStr(FolderPath, (length(FolderPath)-1));
12.     // Check if the folder exists
13.     if DirectoryExists(FolderPath) then
14.     begin
15.       // Check if the folder is read-only
16.       if FindFirst(FolderPath, faAnyFile, FolderInfo) = 0 then
17.       begin
18.         Result:= (FolderInfo.Attr and faReadOnly) <> 0;
19.         FindClose(FolderInfo);
20.       end else
21.         Result:= False;
22.     end;
23.   end;
24. end;

[Zvoni]

Code: Pascal  [Select][+][-]

1. function CheckIfFolderIsReadOnly(FolderPath: String): Boolean;
2. var
3.   FolderInfo: TSearchRec;
4.   SelectedNode: TTreeNode;
5. begin
6.   // Get the selected node
7.   SelectedNode := Browser.myTreeView.Selected;
8.   if Assigned(SelectedNode) then
9.   begin
10.     // remove last delimiter
11.     LeftStr(FolderPath, (length(FolderPath)-1));
12.     // Check if the folder exists
13.     if DirectoryExists(FolderPath) then
14.     begin
15.       // Check if the folder is read-only
16.       if FindFirst(FolderPath, faAnyFile, FolderInfo) = 0 then
17.       begin
18.         Result:= (FolderInfo.Attr and faReadOnly) <> 0;
19.         FindClose(FolderInfo);
20.       end else
21.         Result:= False;
22.     end;
23.   end;
24. end;

This looks weird to me

Code: Pascal  [Select][+][-]

1. Result:= (FolderInfo.Attr and faReadOnly) <> 0;
2.  

Would have expected

Code: Pascal  [Select][+][-]

1. Result:= (FolderInfo.Attr and faReadOnly) = faReadOnly;

[petevick]

Well after all that I came across one of my own posts querying the DirectoryIsWritable() function which as leads to the my revised and simpler function that works (although I do have to try it in Windows yet) I switch the boolean result so it matches TShellTreeView.ReadOnly property......

Code: Pascal  [Select][+][-]

1. function CheckIfFolderIsReadOnly(FolderPath: String): Boolean;
2. var
3.   SelectedNode: TTreeNode;
4. begin
5.   // Get the selected node
6.   SelectedNode := Browser.myTreeView.Selected;
7.   if Assigned(SelectedNode) then
8.   begin
9.     if DirectoryExists(FolderPath) then
10.     begin
11.       // Check if the folder is read-only
12.       Result:= DirectoryIsWritable(FolderPath);
13.       Result:= not Result;
14.     end;
15.   end;
16. end;

[wp]

This looks weird to me

Code: Pascal  [Select][+][-]

1. Result:= (FolderInfo.Attr and faReadOnly) <> 0;
2.  

Would have expected

Code: Pascal  [Select][+][-]

1. Result:= (FolderInfo.Attr and faReadOnly) = faReadOnly;

Why? faReadOnly represents a single bit only (faReadOnly   = $00000001). Therefore both statements are correct.

[petevick]

..........
Would have expected

Code: Pascal  [Select][+][-]

1. Result:= (FolderInfo.Attr and faReadOnly) = faReadOnly;

That's what I had orginally which also didn't work.

[Zvoni]

OK, noticed something "weird" (on Windows):
I declared a Test-Folder to be readonly. OK.
BUT..... This Folder inherits Attributes from its Parent-Folder, and that one removed the ReadOnly-Flag when i was reading it again.....

[KodeZwerg]

I am unsure about the problems you encounter but specific on windows i would do it in a similar way

Code: Pascal  [Select][+][-]

1. var
2.  attr: Integer;
3. begin
4.  attr := FileGetAttr('C:\SomeDirectory');
5.  if (attr and faReadOnly) <> 0 then

And I always just test if a bit is included (<>0)

[petevick]

Tested in Windows and works correctly.

Thanks to all for the help