I can't retrieve the user input information in a table when the user closes the table.

Hello,

I am trying to collect the information of a popup uitable in MATLAB GUI with the DeleteFcn property, but it keeps giving me this error:

Unrecognized function or variable 'MyDeleteFcn'.

f = figure('Name','Info.','NumberTitle','off');
set(gcf, 'Units', 'Inches', 'Position', [7, 3, 3.8, 6], 'PaperUnits', 'Inches', 'PaperSize', [16, 9.0]);
t = uitable(f,'Position',[10 5 400 565],'ColumnWidth',{150,150},'ColumnEditable',[false true], 'DeleteFcn','data = MyDeleteFcn(gcbo)');
set(t,'Data',[matrix1, matrix2]); % Use the set command to change the uitable properties.
set(t,'ColumnName',{'';''});
uiwait

However, I defined this function earlier in the GUI

function data = MyDeleteFcn(t)
data = get(t,'Data');

Could anyone tell me what is it that I'm doing wrong?

My goal is to collect the information of a popup uicontrol as soon as the user closes the table in a GUI.

Any help is much appreciated.

Answer 1

[Adam Danz]

Callback functions do not return outputs. You must store the values somewhere and then retreive them. Here's a solution to this problem:

Step 1: Pass the GUI handle in to the delete function

mainGUIhandle is a handle to the main GUI figure.

% Create the UITable and its parent figure
f = figure('Name','Info.','NumberTitle','off');
t = uitable(f,'DeleteFcn', {@MyDeleteFcn, mainGUIhandle}); % mainGUIhandle is handle to main GUI
set(t,'Data',rand(10,3));

Step 2: Define delete function, store UITable data in main GUI

function data = MyDeleteFcn(hObj, event, GUIhandle)
  data = hObj.Data;             % Get data from UI table
  dat = guidata(GUIhandle);     % Get data stored in main GUI (if any)
  dat.data = data;              % Store the UI table data
  guidata(GUIhandle, dat)       % Load the data into the main GUI

Step 3: Retrieve data from any callback function that has access to the main GUI handle

mainGUIhandle is a handle to the main GUI figure.

  % From any callback function that has access to the main GUI figure handle
  dat = guidata(mainGUIhandle);
  dat.data  % This is the UITable data

[Feri]

Thank you for your help Adam,

Could you please help me with how to implement your solution to my GUI.

I get this error:

Unrecognized function or variable 'mainGUIhandle'.

Where should I define this function?

[Feri]

This is the part of the GUI I am now:

if ischar(Header{1,1}) == 0  % checks for the proper heading
    
    selection = questdlg( ...
      'Do you want to manually enter Information?','Wrong header info.', ...
      'Yes','No','No');
  
    switch selection
        case 'Yes'
            matrix1 = {'Device';'Motion Profile';'Size'; 'Pitch'; 'Surface Form'; 'Nominal ROC'; 'Sensor Sampling'; 'Scan Velocity'; 'k'; 'c';...
                'A1'; 'A2'; 'A3'; 'A4'; 'A5'; 'A6'; 'A7'; 'A8'; 'A9'; 'A10'; 'A11'; 'A12'; 'A13'; 'A14'; 'A15'; 'A16'; 'A17'; 'A18'; 'A19'; 'A20'; };
            matrix2 = {''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''; ''};
 
            f = figure('Name','Info.','NumberTitle','off');
            set(gcf, 'Units', 'Inches', 'Position', [7, 3, 3.8, 6], 'PaperUnits', 'Inches', 'PaperSize', [16, 9.0]);
            handles.t = uitable(f,'Position',[10 5 400 565],'ColumnWidth',{150,150},'ColumnEditable',[false true]);
            set(handles.t,'Data',[matrix1, matrix2]); % Use the set command to change the uitable properties.
            set(handles.t,'ColumnName',{'';''});
            uiwait
            
        case 'No'
            mb = msgbox('Cannot continue', 'Error','Error');
            return   
    end
end

[Adam Danz]

I think you're opening the UITable from within a GUI, is that correct? If so, the mainGUIhandle variable is the handle to your main GUI as I explained twice in my answer.

If you're using GUIDE, that handle is stored somehwere in the handles structure.

[Feri]

Yes, I open it from within the GUI, however, I get this error:

Error using guidata (line 87)

Object must be a figure or one of its child objects.

Error in Viewer>LoadDataTag_Callback (line 197)

dat = guidata(handles);

I defined the delete function and stored it as you said, then defined the table and its figure; but then this error.

Could you help me with this?

Thank you.

[Adam Danz]

mainGUIhandle is the handle to your GUI figure.

If you're using GUIDE (which is still unclear to me), then the GUI's figure handle is stored as a field in the handles structure.

[Feri]

Yes, I am using GUIDE, and I changed the mainGUIhandle to "handles" as the input arguments,

function Tdata = MyDeleteFcn(hObject, eventdata, handles)
Tdata = hObject.Data;             % Get data from UI table
dat = guidata(handles);     % Get data stored in main GUI (if any)
dat.Tdata = Tdata;              % Store the UI table data
guidata(handles, dat)       % Load the data into the main GUI

this is defined inside the main body of the GUI,

then in a push button the data is to be stored

f = figure('Name','Info.','NumberTitle','off');
set(gcf, 'Units', 'Inches', 'Position', [7, 3, 3.8, 6], 'PaperUnits', 'Inches', 'PaperSize', [16, 9.0]);
t = uitable(f,'Position',[10 5 400 565],'ColumnWidth',{150,150},'ColumnEditable',[false true], 'DeleteFcn', {@MyDeleteFcn, handles});
set(t,'Data',[matrix1, matrix2]); % Use the set command to change the uitable properties.
set(t,'ColumnName',{'';''});
dat = guidata(handles);
dat.Tdata  % This is the UITable data

I appreciate you taking the time to respond to me, and am really trying to understand the logic...Just can't make it work

[Adam Danz]

Once again, handles is a structure. Structures have fields. Your GUI's figure handle is one of the fields in the structure. Here's an example.

handles.MyGUI_Figure 
handles.MyAxes
handles.MyButton

In this example, handles.MYGUI_Figure is the handle to the figure.

mainGUIhandle = handles.MyGUI_Figure; 

***I don't know what your figure handle is named. You must look in the handles structure and identify which field contains your figure handle.

[Feri]

here is a screenshot of the handles, I did mainGUIhandle = handles.figure1 and got the same error.

I defined the table as handles.t = uitable(), and passed that to the deletefcn and got the same error.

I don't know what I'm doing wrong.

[Adam Danz]

Please attach the m-file and the fig-file or copy-paste the full error message the the relevant section of code that produced the error.

[Feri]

Attached please find the .m and .fig file, as well as a .csv file,

When loading the data you will be asked if you want to enter the data manually, thats where the error ocures.

I really appreciate your help.

[Adam Danz]

"I did mainGUIhandle = handles.figure1 and got the same error."

An important lesson here is attention to detail. handles.figure1 is the correct handle to use. After you made that change, you did get an error but it was not the same error nor was the error caused by the same line of code.

The problem is that your code doesn't follow the steps I explained in my anwer. In step1, the figure handle (handle.figure1) is merely passed to the delete function. This happens in LoadDataTag_Callback.

handles.t = uitable(f,. . . 'DeleteFcn', {@MyDeleteFcn, handles.figure1});

Remove the two dat lines that follow.

[Feri]

My God!!! I am sorry...

It works perfect. I really really appreciate your help :)

[Adam Danz]

No need to appologize :)

I enjoy helping others learn so please absorb the bigger lesson here: take time to understand the logic of the code even if you don't understand what each line is doing and pay close attention to error messages or unexpected results.

[Feri]

I really am grateful for your help and time.

One more thing (I don't know if I should open a new thread), the first time I run the GUI it gives an error:

Reference to non-existent field 'data'.

But the next time I run it, it shows the input values of the previous time.

I tried creating an empty cell in the openfcn but didn't help. How can I resolve that?

Regards,

Feri.

[Adam Danz]

handles.data isn't assigned until you delete the UITable. If there's a part of your code that tries to reference handles.data prior to creating and deleting the UI table, the data field will not exist in the handles structure.

There are two ways around that.

1) Create a default value for handles.data in your opening function. It could be something like,

handles.data = zeros(100,3);  % Or whatever size you expect; or maybe nan(100,3)
guidata(handles.figure1, handles)  

2) Only access handles.data when data is a field in handles. This condition below can be placed anywhere in your code that tries to access that field.

if isfield(handles,'data')
    % your code here
else
    % whatever your default action is.  
    % Example 1
    return  % leave the callback function
    % Example 2
    warning('No ''data'' field in handles')  % Throw a warning
    % etc....
end

BTW, you should rename variables so they make sense to you. I noticed your delete function was the same name I used: MyDeleteFcn. That's generic and not descriptive. A better name would be UITableDeleteFcn. Same goes with warning messages etc.

[Feri]

Adam, there isn't any line that wants to access handles.data before the execution of the MyDeleteFcn, the error occurs a few line after the table is created, filled in, and then deleted.

I defined an empty cell, handles.data = cell(30,2); but then for the first time after filling in the table it gives empty cells until the next run that produces the results of the previous one.

[Adam Danz]

Could you attach the updated m-file and share the full copy-pasted error message so I know what lines to look at?

[Feri]

Attached please find the files, and here is the error:

Reference to non-existent field 'Tdata'.

Error in Viewer>LoadDataTag_Callback (line 194)

Header = handles.Tdata(:,2)

Error in gui_mainfcn (line 95)

feval(varargin{:});

Error in Viewer (line 42)

gui_mainfcn(gui_State, varargin{:});

Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)Viewer('LoadDataTag_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback.

[Feri]

I found the issue, I didn't follow your step 3 completely. Slow learner.

Thanks a million.

[Adam Danz]

Good work!

Answer 2

[Walter Roberson]

When you use a quoted string to define a callback, the statement is evaluated inside the base workspace. It can only access functions that are defined as the first function inside of a .m file because it is not evaluated within the scope of your gui.

Adam has given you some good advice.

There is a hack, though: you can use

 assignin('base', 'MyDeleteFcn', @MyDeleteFcn)

Then when the callback executes within the base workspace, the MyDeleteFcn that is seen in the base workspace is the function handle to the internal function.

The variable assigned to in the callback string will go into the base workspace.

[Feri]

Thank you.

I should have everything inside the GUI, would you be able to help me with how to edit my code, so that the table information is saved in Swith Case 'Yes' when the user closes the table?

Thanks a million.

[Adam Danz]

I didn't know about this, Walter. Thanks! What advantage is there for using this syntax? It seems limited and even difficult to debug, unless I'm not understanding it correctly. I'll have to tinker with it some time.