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How to create an empty edit field (numeric) in app designer

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John Cadigan
John Cadigan on 5 Apr 2019
Commented: frankenberry on 21 May 2020
I am writing an app that has a user enter a quantity in a numeric Edit Field. The field starts off with a default value of 0 so that the user has to delete the 0 and then enter the number. Is there a way to get the default to be empty rather than a 0?

  1 Comment

Marc Youcef
Marc Youcef on 13 Aug 2019
I was searching for same request but apprently there is no way to do that using uinumericeditfield as this edit field forces you to have at list a numeric value. Which is a pain when you do not want the user to necessarly enter something in, you get a 0 value instead of empty field...

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Answers (2)

Chris
Chris on 13 Aug 2019
Can you make the input a text field and reject anything that does not convert to a number?

  2 Comments

Marc Youcef
Marc Youcef on 13 Aug 2019
Yes, this is the only solution I thought about. Unfortunately in my case I was trying to take advantage of the 'uinumericeditfield' functionnality which is doing exactly this for you and wanted to simply add an 'empty by default' option.
frankenberry
frankenberry on 21 May 2020
I was able to use a blank text area to accept only numbers. I'm not sure how good it is or if it helps you at all. The only problem I have with this is that if the field is blank, it should also give an error. That is, I get an error if the value is not a number and the error box pops up or if it is blank, I should get an error. I need to code that part yet. I tested this and it works in my app. I don't get an error when numbers are entered.
% Value changed function: NEQO_A4_pistol
function NEQO_A4_pistolValueChanged(app, event)
value = app.NEQO_A4_pistol.Value;
string(value);
if isempty(str2num(value))
app.NEQO_A4_pistol.Value,value;'0';
uialert(app.UIFigure, {'You need to enter a number','Click OK and enter a number value'}, 'Error', 'Icon', 'Error');
app.NEQO_A4_pistol.Value = '';
elseif ~isempty(str2num(value))
app.NEQO_A4_pistol.Value,value;'0', '1', '2', '3', '4', '5', '6', '7', '8', '9';
%uialert(app.UIFigure, {'You entered a number! WOOHOO!'}, 'Info', 'Icon', 'info');
end
end

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Gonzalo Montero
Gonzalo Montero on 12 Dec 2019
I'm looking for the same feature, it's a pity that is not possible!

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