How to get output of eventhandler function to main function

I have written a code that is linked to Outlook via actxserver in order to get data from the latest mail i got. I wish to process the event function and then pass the output of it back to the main function, where i want to further process the data (parse it). But i get this error:

Error using registerevent
Too many output arguments.

My main function is:

outlook = actxserver('Outlook.Application');
[subject, body] = registerevent(outlook,{'NewMail', 'MailEvent'})
% some more code where i need subjct and body data
%...

and the MailEvent function is:

function [subject, body] = MailEvent(varargin)
outlook = varargin{1};
% Retrieving last email
mapi=outlook.GetNamespace('mapi');
INBOX=mapi.GetDefaultFolder(6);
count = INBOX.Items.Count; %index of the most recent email.
firstemail=INBOX.Items.Item(count); %imports the most recent email
INBOX.Items.Item(count).Unread=0;
subject = firstemail.get('Subject');
body = firstemail.get('Body');
end

If i leave the output away and use it this way it works, but the subject and body data is "captured" in the Mailevent workspace

outlook = actxserver('Outlook.Application');
registerevent(outlook,{'NewMail', 'MailEvent'})

How can i solve this ?

Answer 1

[Vatsal]

Hi,

The issue you are facing is due to the fact that the "registerevent" function in MATLAB does not support output arguments. It is designed to register a callback function (in given case, MailEvent) that gets executed when a specific event occurs. However, it does not return any values from the callback function.

A potential solution involves the use of global variables to transfer data from the MailEvent function to the main function.

The code could be adjusted in the following manner:

% Declare global variables
global subject body

% Your main function
outlook = actxserver('Outlook.Application');
registerevent(outlook,{'NewMail', 'MailEvent'})

% Now subject and body can be accessed here
% some more code where you need subject and body data
%...

% MailEvent function
function MailEvent(varargin)
    % Make sure to declare the variables as global in this function as well
    global subject body

    outlook = varargin{1};
    % Retrieving last email
    mapi=outlook.GetNamespace('mapi');
    INBOX=mapi.GetDefaultFolder(6);
    count = INBOX.Items.Count; %index of the most recent email.
    firstemail=INBOX.Items.Item(count); %imports the most recent email
    INBOX.Items.Item(count).Unread=0;
    subject = firstemail.get('Subject');
    body = firstemail.get('Body');
end

I hope this helps!