Display Progress Monitor for HTTP Message - MATLAB & Simulink (original) (raw)

This example shows how to implement a progress monitor,MyProgressMonitor, that displays a progress bar for data transferred to and from a website. The monitor displays a progress bar in a window created by the MATLAB® waitbar function. It uses set.Direction andset.Value methods to monitor changes to theDirection and Value properties.

Each time MATLAB sets the Direction property,MyProgressMonitor creates a progress bar window and displays either a sending or a receiving message.

Create the following MyProgressMonitor class file.

The class initializes the Interval property to.001 seconds because the example sends only 1 MB of data. The small interval allows you to observe the progress bar.

classdef MyProgressMonitor < matlab.net.http.ProgressMonitor properties ProgHandle Direction matlab.net.http.MessageType Value uint64 NewDir matlab.net.http.MessageType = matlab.net.http.MessageType.Request end

methods
    function obj = MyProgressMonitor
        obj.Interval = .001;
    end
    
    function done(obj)
        obj.closeit();
    end
    
    function delete(obj)
        obj.closeit();
    end
    
    function set.Direction(obj, dir)
        obj.Direction = dir;
        obj.changeDir();
    end
    
    function set.Value(obj, value)
        obj.Value = value;
        obj.update();
    end
end

methods (Access = private)
    function update(obj,~)
        % called when Value is set
        import matlab.net.http.*
        if ~isempty(obj.Value)
            if isempty(obj.Max)
                % no maximum means we don't know length, so message 
                % changes on every call
                value = 0;
                if obj.Direction == MessageType.Request
                    msg = sprintf('Sent %d bytes...', obj.Value);
                else
                    msg = sprintf('Received %d bytes...', obj.Value);
                end
            else
                % maximum known, update proportional value
                value = double(obj.Value)/double(obj.Max);
                if obj.NewDir == MessageType.Request
                    % message changes only on change of direction
                    if obj.Direction == MessageType.Request
                        msg = 'Sending...';
                    else
                        msg = 'Receiving...';
                    end
                end
            end
            if isempty(obj.ProgHandle)
                % if we don't have a progress bar, display it for first time
                obj.ProgHandle = ...
                    waitbar(value, msg, 'CreateCancelBtn', ...
                        @(~,~)cancelAndClose(obj));
                obj.NewDir = MessageType.Response;
            elseif obj.NewDir == MessageType.Request || isempty(obj.Max)
                % on change of direction or if no maximum known, change message
                waitbar(value, obj.ProgHandle, msg);
                obj.NewDir = MessageType.Response;
            else
                % no direction change else just update proportional value
                waitbar(value, obj.ProgHandle);
            end
        end
        
        function cancelAndClose(obj)
            % Call the required CancelFcn and then close our progress bar. 
            % This is called when user clicks cancel or closes the window.
            obj.CancelFcn();
            obj.closeit();
        end
    end
    
    function changeDir(obj,~)
        % Called when Direction is set or changed.  Leave the progress 
        % bar displayed.
        obj.NewDir = matlab.net.http.MessageType.Request;
    end
end

methods (Access=private)
    function closeit(obj)
        % Close the progress bar by deleting the handle so 
        % CloseRequestFcn isn't called, because waitbar calls 
        % cancelAndClose(), which would cause recursion.
        if ~isempty(obj.ProgHandle)
            delete(obj.ProgHandle);
            obj.ProgHandle = [];
        end
    end
end

end

To start the operation, specify the progress monitor.

opt = matlab.net.http.HTTPOptions(... 'ProgressMonitorFcn',@MyProgressMonitor,... 'UseProgressMonitor',true);

Create the data.

x = ones(1000000,1,'uint8'); body = matlab.net.http.MessageBody(x);

Create the message. The httpbin.org/put service returns data received in a PUT message.

url = matlab.net.URI('http://httpbin.org/put'); method = matlab.net.http.RequestMethod.PUT; req = matlab.net.http.RequestMessage(method,[],body);

Send the message.

[resp,~,hist] = req.send(url,opt);

See Also

ProgressMonitor | waitfor