Display a string output in a Edit Field Text box in App-Designer

Hello, I have am developing a matlab app, where the app user inputs a number to a numeric edit field, and I need to output a string from a if statement seperating the different values. I am unable to get the text to display in the area?

 function EntertheNumberofPeopleStayingEditFieldValueChanged(app, event)
            People = app.EntertheNumberofPeopleStayingEditField.Value;
           
            Liters = People * 150;
            
            scatter(app.UIAxes,People,Liters)
 end

        % Value changed function: EditField
        function EditFieldValueChanged(app, event)
 if People > 4
                text1 = sprintf('This is too many people for this shelter to accomodate.\n');
            elseif People <= 0
                text1 = sprintf('No water is needed.\n');
            else 
                text1 = sprintf('Water needs are displayed here >>>\n');
            end
            
            app.EditField.Value = text1;

[Adam Danz]

Is the edit field text or numeric?

Is the edit field large enough for these long lines?

Are you wrapping the text?

What do you mean "unable to get the text to display in the area"?

Lots of unknowns here....

[Alex Smith]

The edit field is text, it is long enough for the lines. I have another edit field that takes in a number and uses it of rsome calculations and runs through the if statement shown above which is meant to output the text to the other edit field depending on what number is input by the user.

[Adam Danz]

Is EditField the edit field that should be updated or is it the edit field that receives the numeric input?

Are there any error messages?

[Alex Smith]

EditField is the output area. A number is entered into the EntertheNumberofPeopleStayingEditField. No error messages are displayed.

[Adam Danz]

But I don't see where EditFieldValueChanged() is called.

If that function is supposed to be evoked by changes to EntertheNumberofPeopleStayingEditField, then shouldn't it be called from that function?

Answer 1

[Cris LaPierre]

You have split your code between two different callback functions. However, only one will execute when a user inputs a value.

For your case, it is better if you put all the code you want to have happen when someone enters a number in the EntertheNumberofPeopleStayingEditFieldValueChanged callback function. Only this function will execute when the user changes this edit field's value.

In addition, keep in mind variable scope for a function. The variable People is only available inside the function that creates it.

function EntertheNumberofPeopleStayingEditFieldValueChanged(app, event)
People = app.EntertheNumberofPeopleStayingEditField.Value;

Liters = People * 150;

scatter(app.UIAxes,People,Liters)

if People > 4
    text1 = sprintf('This is too many people for this shelter to accomodate.\n');
elseif People <= 0
    text1 = sprintf('No water is needed.\n');
else
    text1 = sprintf('Water needs are displayed here >>>\n');
end

app.EditField.Value = text1;
end