Документация

% Data contains one or more CRLF-separated JSON structures.  
% Each structure is one of the format:
%   {"heartbeat"="timestamp"}
%   {"tick"="timestamp", "bid"=bid, "ask"=ask}
% where timestamp is a GMT time and bid and ask are numbers.

classdef PricesStreamer < matlab.net.http.io.StringConsumer
    % PricesStreamer accepts streamed JSON 
    % and displays the result in a uitable in a figure window.
    
    % Copyright 2016-2017 The MathWorks, Inc.
    properties
        Figure
        Table
        Endit logical
        HaveTick logical
    end
    
    methods (Access=protected)
        function length = start(obj)
            if obj.Response.StatusCode ~= matlab.net.http.StatusCode.OK
                length = 0;
            else
                length = obj.start@matlab.net.http.io.StringConsumer;
                obj.Figure = figure('CloseRequestFcn',@obj.endit);
                obj.Figure.Position(4) = 550;
                obj.Figure.Position(2) = 50;
                obj.Table = uitable(obj.Figure,...
                    'ColumnName',{'Time','Bid','Ask'},...
                    'ColumnWidth',{130,'auto','auto'});
                obj.Table.Position(4) = 500;
                obj.Table.Data = cell(0,3);
                obj.Endit = false;
                obj.HaveTick = false;
            end
        end
    end
    
    methods
        function [len,stop] = putData(obj, data)
            % Data contains one or more CRLF-separated JSON structures.  
            % Each structure is one of the format:
            %   {"heartbeat"="timestamp"}
            %   {"tick"="timestamp", "bid"=bid, "ask"=ask}
            % where timestamp is a GMT time and bid and ask are numbers.
            if obj.Endit
                data = [];
                delete(obj.Figure);
            end
            first = obj.CurrentLength + 1;
            [len,stop] = obj.putData@matlab.net.http.io.StringConsumer(data);
            if isempty(data) || stop
                if ischar(data)       % data == '' means user ctrl/c'ed, so set to
                    obj.Endit = true; % delete figure on next close
                end
                stop = true;
            else
                stop = false;
                last = obj.CurrentLength;
                newData = obj.Response.Body.Data.extractBetween(first,last);
                % split at CRLFs
                strings = strsplit(newData, '\r\n');
                try
                    cellfun(@obj.displayJSON, strings);
                catch e
                    fprintf('Error on JSON:\n%s<EOF>\n',data);
                    obj.Endit = true;
                    rethrow(e);
                end
            end
        end
        
        function displayJSON(obj, str)
            if ~isempty(str)
                try
                    val = jsondecode(str);
                catch e
                    fprintf('Error "%s" on JSON:\n%s<EOF>\n',e.message,str);
                    rethrow(e);
                end
                if isfield(val,'tick')
                    tick = val.tick;
                    newdata = {cvtime(val.tick.time),tick.bid,tick.ask};
                    setExtent = ~obj.HaveTick;
                    obj.HaveTick = true;
                elseif isfield(val, 'heartbeat')
                    newdata = {cvtime(val.heartbeat.time),'',''};
                    setExtent = false;
                end
                obj.Table.Data = [newdata;obj.Table.Data];
                if setExtent || ~mod(log10(length(obj.Table.Data)),1)
                    % set extent on first tick and every power of 10
                    % add 15 for width of scroll bar
                    obj.Table.Position(3) = obj.Table.Extent(3) + 15;
                end
                drawnow
            end
        end
        
        function endit(obj,~,~)
            % endit callback from close(obj.Figure)
            if exist('obj','var') && isvalid(obj)
                if obj.Endit
                    if isvalid(obj.Figure)
                        delete(obj.Figure);
                    end
                else
                    obj.Endit = true;
                end
            end
        end
        
        function delete(obj)
            if ~isempty(obj.Figure) && isvalid(obj.Figure)
                delete(obj.Figure);
            end
        end
    end
end

function time = cvtime(time)
% Format time data for display
time = datetime(time,'InputFormat','yyyy-MM-dd''T''HH:mm:ss.S''Z''','TimeZone','GMT');
time.TimeZone = 'local';
time = char(time, 'dd-MMM-yyyy HH:mm:ss.S');
end

first = obj.CurrentLength + 1;
[len,stop] = obj.putData@matlab.net.http.io.StringConsumer(data);
last = obj.CurrentLength;
newData = obj.Response.Body.Data.extractBetween(first,last);
% split at CRLFs
strings = strsplit(newData, '\r\n');

function displayJSON(obj, str)
...
val = jsondecode(str);
if isfield(val,'tick')
    tick = val.tick;
    newdata = {cvtime(val.tick.time),tick.bid,tick.ask};
    ...
elseif isfield(val, 'heartbeat')
    newdata = {cvtime(val.heartbeat.time),'',''};
    ...
end
obj.Table.Data = [newdata;obj.Table.Data];
...
end

url = matlab.net.URI('<URL>','accountId',<YOUR_ACCOUNT_ID>,'<NAME>','<VALUE>');
authInfo = matlab.net.http.AuthInfo(matlab.net.http.AuthenticationScheme.Bearer,...
    'Encoded','<YOUR_CREDENTIALS>');
af = matlab.net.http.field.AuthorizationField('Authorization',authInfo);
r = matlab.net.http.RequestMessage('get',af);
consumer = PricesStreamer;
% SavePayload set to retain all results - useful for debugging
[resp,req,hist] = r.send(url,matlab.net.http.HTTPOptions('SavePayload',true),consumer);
% Show the results for debugging
show(resp)