Whay not working saveChanges(DD) in mscript?

I opened DD in mscript, set the value of a particular field in the parameter item to a new value, and then updated DD with saveChanges() api

When you check the parameter values in the Matlab console window, it seems to be updated well

When I open the actual DD, the value doesn't change

Why is that?

I'll leave my mscript at the bottom. Need help

---

function updateParametervalue()

parameters = evalin('base','parameters');

DD = evalin('base','ParamDD');
if isempty(DD)
    disp('Parameter of DataDictionary is empty.');
else
    DataSecObj = getSection(DD, 'Design Data');
    DdVarList = find(DataSecObj);

    DdFile = evalin('base','DdFile');

    idx_DataSource = strcmp({DdVarList(:).DataSource}, DdFile);

    DdVarNameAll = {DdVarList(:).Name};

    DdVarName = DdVarNameAll(idx_DataSource);

    num_iter = length(DdVarName);
    
    paramName = parameters{1};
    param2 = parameters{2};
    param3 = parameters{3};
    param4 = parameters{4};

    for idx_var = 1:num_iter
        VarPropEntry = getEntry(DataSecObj, DdVarName{idx_var});
        value = getValue(VarPropEntry);
        if ~isa(value, 'Simulink.Parameter')
            continue;
        end

        if VarPropEntry.DataSource ~= DdFile
            continue;
        end

        if strcmp(paramName, VarPropEntry.Name)
           value.param2Property = param2;
           if(strcmp(param4, 'null'))
                value.param4Property = '';
           else
               value.param4Property = param4
           end

           if ~isempty(param3)
               dataType = value.DataType;
           end


	   saveChanges(DD);

           break;
        end
        
    end

end


end

[Yash]

Hi Sua,

Can you please provide the information regarding the Variable "ParamDD" ? Is it a Simulink.data.Dictionary object?

If yes, please share the SLDD file and the caller code here, so that we can reproduce and resolve the issue.

Answer 1

[Githin George]

Hi Sua,

I could find some issues in the script, and I have fixed it. I am making a few assumptions along the way (check the code comments).

Summary of the Changes Made:

• Within the for loop, I am extracting the value of the SLDD parameter with the name matching with “parameters{1}” and modifying with the values provided in the input value “parameters”.
• Use the “setValue” function to write the modified “Simulink.Parameter” value into the SLDD. Refer to the documentation below.

https://www.mathworks.com/help/simulink/slref/simulink.data.dictionary.entry.setvalue.html#bumgf8a-1-entryObj

• Saving the changes to the SLDD file using saveChanges.

function updateParametervalue()

% available in base workspace
parameters = evalin('base','parameters'); % Contains new data to modify the properties of data in the SLDD with name parameters{1} 
DD = evalin('base','ParamDD');

if isempty(DD)
    disp('Parameter of DataDictionary is empty.');
else
    DataSecObj = getSection(DD, 'Design Data');
    DdVarList = find(DataSecObj);
    DdFile = evalin('base','DdFile');
    idx_DataSource = strcmp({DdVarList(:).DataSource}, DdFile);
    DdVarNameAll = {DdVarList(:).Name};
    DdVarName = DdVarNameAll(idx_DataSource);
    num_iter = length(DdVarName);
    paramName = parameters{1}; % ParameterName?
    param2 = parameters{2}; % newValue?
    param3 = parameters{3}; % newDatatype?
    param4 = parameters{4}; % ??
    for idx_var = 1:num_iter
        VarPropEntry = getEntry(DataSecObj, DdVarName{idx_var});
        value = getValue(VarPropEntry); % value is of type Simulink.Parameter
        if ~isa(value, 'Simulink.Parameter')
            continue;
        end
        if VarPropEntry.DataSource ~= DdFile
            continue;
        end
        if strcmp(paramName, VarPropEntry.Name)
            value.Value = param2;
            % if(strcmp(param4, 'null'))
            %     value.param4Property = '';
            % else
            %     value.param4Property = param4
            % end
            if ~isempty(param3)
                value.DataType = param3;
            end
            % Use setValue to write the modified value back to SLDD
            setValue(VarPropEntry,value)
            % SaveChanges
            saveChanges(DD);
            break;
        end
    end
end
end

Additionally, I would suggest that you provide the SLDD object, and filenames as input arguments to the function instead of performing “evalin” on the base workspace. Ideally you can rework the code to break the entire for loop and query for only the SLDD data related to "parameters{1}".