What is my issue with Caller Scope in the Nested Callback Function here?

Would appreciate anyone's advice on how to solve the issue here regarding Nested Function Caller Scope. I expected changes made to dataStack within the nested function cbfRefreshTable to be reflected in ALL instances of dataStack throughout the file (since they share scope).

You should be able to save the function below and run it yourself (if you have the database toolbox and a SQL Server table to use). I've included the function ic_fetchSQLData.m too which you'll need to save seperately.

[fHandle,uiHandle] = ic_sqlTableGUIEditor('MySchema.MyTable',dbConnObj);

Note the line with comment "% changes made to dataStack in cbfRefreshTable are not present in this variable". Here dataStack will not reflect changes made to it with the fastinsert (assuming you have made changes to the table using the GUI).

Greatly appreciate anyone's help here.

      function [fHandle,uiHandle] = ic_sqlTableGUIEditor(varargin)
      if nargin >= 1
          tableName = varargin{:,1};
          connCredit = varargin{:,2};
      end

      %%RETRIEVE CREDIT TABLE DATA

      sqlQuery = ['SELECT * FROM ' tableName];
      [dataStack,dataHeaders] = ic_fetchSQLData(connCredit,sqlQuery);
      if size(dataStack(:,1)) ~= size(unique(dataStack(:,1)))
          error('The leftmost column of SQL table is not unique');
      end

      if ~isempty(dataStack)
          numericFlag = all(cellfun(@isnumeric,dataStack),1);
      else
          numericFlag = false(size(dataHeaders,1)); % this default will cause problems
      end

      [r,c] = size(dataStack);

      % save backup to current directory as precaution
      save(fullfile(cd(),'dataStack.mat'),'dataStack');
      save(fullfile(cd(),'dataHeaders.mat'),'dataHeaders');

      %%INSTANTIATE FIGURE CONTROLS AND INITIALISE PROPERTIES

      buff = 140; % Additional Table Width for each column more than 4

      fHandle = figure('Position',[300, 500, 340+(c>=4)*buff*(c-4), 500],'name',tableName,'menubar','none','Resize','off');
      columnFormat = repmat({'numeric'},1,c); columnFormat(~numericFlag) = {'char'};

      uiHandle = uitable('Parent',fHandle,'Units','normalized','Position',[0.05 0.05 0.9 0.8],...
          'Data',dataStack,'ColumnName',dataHeaders,...
          'ColumnEditable',true(1,c),'ColumnFormat',columnFormat);

      searchTextHandle = uicontrol(fHandle,'Style','edit','Position',[30 440 125 20],...
          'Callback',{@cbfSearchTable,dataStack},...
          'TooltipString','Enter Text to Search - Searching will Purge any Changes not Committed ');

      insertRowHandle = uicontrol(fHandle,'Style','pushbutton','Position',[30 470 125 20],...
          'String','Insert Row','Tag','InsertRow','Callback',@cbfInsertRow,...
          'TooltipString','Insert New Row');

      deleteRowHandle = uicontrol(fHandle,'Style','pushbutton','Position',[160, 470, 125, 20],...
          'String','Delete Row','Tag','DeleteRow','Callback',@cbfDeleteRow,...
          'TooltipString','Delete Row from Interface Table');

      selectRowHandle = uicontrol(fHandle,'Style','popupmenu','Position',[290, 475, 45, 15],...
          'String',1:size(get(uiHandle,'Data'),1),'Tag','SelectRow',...
          'TooltipString','Re-Query SQL Table', 'Max', 1, 'Min', 1, 'Value', 1);

      refreshTableHandle = uicontrol(fHandle,'Style','pushbutton','Position',[160, 440, 80, 20],...
          'String','Refresh','Tag','CommitTable','Callback',{@cbfRefreshTable,dataStack},...
          'TooltipString','Re-Query SQL Table');

      commitChangesHandle = uicontrol(fHandle,'Style','pushbutton','Position',[250, 440, 80, 20],...
          'String','Commit','Tag','CommitChanges','Callback',{@cbfCommitChanges,dataStack,dataHeaders,numericFlag,tableName},...
          'TooltipString','Commit Changes to SQL Table');

      %%CALLBACK NESTED FUNCTIONS
      % These functions must access variables in-scope

          function cbfInsertRow(hObject,eventdata)

              dataStackinUIT = get(uiHandle,'Data');
              dummyRow = cell(1,c);
              dummyRow(numericFlag) = {NaN}; dummyRow(~numericFlag) = {'-'};
      %         dataStackinUIT = [dataStackinUIT;dummyRow];
              dataStackinUIT = [dummyRow; dataStackinUIT];
              set(uiHandle,'Data',dataStackinUIT);

          end

          function cbfDeleteRow(hObject,eventdata)

              rowNumber = get(selectRowHandle,'Value');
              dataStackinUIT = get(uiHandle,'Data');
              dataStackinUIT_dummy = dataStackinUIT([1:rowNumber-1,rowNumber+1:end],:);
              set(uiHandle,'Data',dataStackinUIT_dummy);
              selectRowHandle = uicontrol(fHandle,'Style','popupmenu','Position',[275 360 50 20],...
                  'String',1:size(get(uiHandle,'Data'),1),'Tag','CommitChanges',...
                  'TooltipString','Re-Query SQL Table', 'Max', 1, 'Min', 1, 'Value', 1);
          end

          function dataStack = cbfCommitChanges(hObject,eventdata,dataStack,dataHeaders,numericFlag,tableName)

              dataStackinUIT = get(uiHandle,'Data');

              % Insert New Rows to SQL Table
              [mask,idx] = ismember(dataStackinUIT(:,1),dataStack(:,1));
              additionsDataset = dataStackinUIT(~mask,:); % i.e. in dataStackinUIT but not dataStack        
              dataStackinUIT = dataStackinUIT(mask,:);       
              if ~isempty(additionsDataset)
                  fastinsert(connCredit,tableName,dataHeaders,additionsDataset);
              end

              % Replace Any Edited Rows in SQL Table
              [mask,idx] = ismember(dataStackinUIT(:,1),dataStack(:,1));
              validationVector = false(size(dataStackinUIT,1),1); % Vector of rows that have changed
              for i = 2:size(dataStack,2)
                  if numericFlag(i) % numeric column
                      validationVector = validationVector | ( (cell2mat(dataStackinUIT(:,i))~=cell2mat(dataStack(idx,i))) & ~isnan(cell2mat(dataStackinUIT(:,i))));               
                  else % text column
                      validationVector = validationVector | ~strcmp(dataStackinUIT(:,i),dataStack(idx,i));                
                  end           
              end
              changesDataset = dataStackinUIT(validationVector,:);

              if ~isempty(changesDataset)
                  keyColumnString = regexprep(strtrim(regexprep(evalc('disp(changesDataset(:,1))'),{' *Col[^\n]*\n','\n'},'')),'''  +''',', ');
                  sqlOrder = ['DELETE FROM ',tableName, ' WHERE ', dataHeaders{1,1}, ' IN '];
                  sqlOrder = [sqlOrder,'(',keyColumnString,')'];
                  exec(connCredit,sqlOrder);
                  fastinsert(connCredit,tableName,dataHeaders,changesDataset);
              end

              dataStack = cbfRefreshTable(hObject,eventdata); % changes made to dataStack in cbfRefreshTable are not present in this variable

          end

          function dataStack = cbfRefreshTable(hObject,eventdata)

              set(fHandle,'Color',[0.0 0.3 0.6]);
              [dataStack,dataHeaders] = ic_fetchSQLData(connCredit,sqlQuery); % here I re-query dataStack and wish to pass it into caller scope
              pause(0.5);
              [r,c] = size(dataStack);
              set(uiHandle,'Data',dataStack);
              set(fHandle,'Color',[0.8 0.8 0.8]);

          end

          function cbfSearchTable(hObject,eventdata,dataStack)
              userText = get(searchTextHandle,'String');
              validationVector = strncmpi(dataStack(:,1),num2str(userText),length(num2str(userText)));

              set(uiHandle,'Data',dataStack(validationVector,:));
          end

      end

*************************************************************************** ************ ANother function to save ********************************* ****************************************************************************

function [dataStack,dataHeaders] = ic_fetchSQLData(conn,sqlQuery)
%
%   [dataStack,dataHeaders] = ic_fetchSQLData(conn,sqlQuery)
%
%   Author:         Mark Whirdy
%   Date:           17/11/2010
%   Last Edited:       ---
%
%
%%FUNCTION MAIN

dataHeaders = [];
curs = exec(conn, sqlQuery);
dataStack = [];
toRun = true; rowLimit = 50000;
while toRun
    curs = fetch(curs, rowLimit);

      dbData = curs.Data;
      dataStack = [dataStack; dbData]; %#ok

      numFetchedRows = size(dbData,1);
      if numFetchedRows < rowLimit
          toRun = false;
      end     
  end

if ~strcmpi(dataStack,'No Data')
    dataHeaders = columnnames(curs, 1)';  
else
    dataStack = [];
end

Anyone comfortable with nested callback scope should see the problem pretty quickly. Grateful for your assistance

Answer 1

[Mark Whirdy]

I used setappadata as a workaround.