Difference between revisions of "Display stock quotes from Yahoo!"

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Line 6: Line 6:
  
 
<html>
 
<html>
   <script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/prototype.js"></script>
+
   <script type="text/javascript" src="https://jsxgraph.uni-bayreuth.de/distrib/prototype.js"></script>
 
   <form>
 
   <form>
 
     <input type="button" value="Start" onClick="Start()">  
 
     <input type="button" value="Start" onClick="Start()">  
Line 140: Line 140:
 
<source lang="php">
 
<source lang="php">
 
<?php
 
<?php
$fp = fopen ("http://finance.yahoo.com/d/quotes.csv?s=^gdaxi&f=sl1d1t1c1ohgv&e=.csv","r");
+
$fp = fopen ("https://finance.yahoo.com/d/quotes.csv?s=^gdaxi&f=sl1d1t1c1ohgv&e=.csv","r");
 
echo fgets ($fp, 1024);
 
echo fgets ($fp, 1024);
 
fclose ($fp);
 
fclose ($fp);

Revision as of 15:43, 10 March 2017

This JSXGraph application fetches the live stock quotes of the German DAX Index (gdaxi) from Yahoo!. The curve is updated only once a second, so initially it needs a little patience until the curve is visible.

Beware that in order to simplify the handling of AJAX we use the additional library prototype.js in this example.

The underlying JavaScript code

var hi, lo, brd, periodical, 
    brd, g, txt, val,
    x = [],
    y = [];


fetchData = function() {
    new Ajax.Request('/ajax/stockquotes.php', {
        onComplete: function(transport) {
            var t, a;
            if (200 == transport.status) {
                t = transport.responseText;
                a = t.split(',');
                x.push(x.length+1);
                y.push(a[1]);
                val = a[1];  // set the text
                if (!g) { 
                    g = brd.createElement('curve', [x,y],{strokeWidth:3, strokeColor:'green',shadow:true}); 
                    txt = brd.createElement('text', [3,(hi+lo)*0.5,function(){return 'GDAXI = '+val;}],{fontSize:14}); 
                    brd.createElement('functiongraph',[JXG.Math.Numerics.regressionPolynomial(1,g.dataX,g.dataY)],{strokecolor:'red',dash:3});
                } else {
                    g.dataX = x;                    
                    g.dataY = y;
                }
                brd.update();
            };
    }});
};

// Fetch max and min, and start the periodical update.
new Ajax.Request('/ajax/stockquotes.php', {
        onComplete: function(transport) {
            var a, t;
            if (200 == transport.status) {
                t = transport.responseText;
                a = t.split(',');
                hi = a[6]*1.00002;
                lo = a[7]*0.99998;
                brd = JXG.JSXGraph.initBoard('jxgbox', {axis:true, boundingbox:[0,hi,200,lo]});
                brd.createElement('axis',[[0,lo],[1,lo]]);
                Start();
            };
    }});


Start = function() {
   if (periodical==null) {
      periodical = setInterval(fetchData,1000);  // Start the periodical update
   }
};

Stop = function() {
   if (periodical!=null) {
       clearInterval(periodical);
       periodical = null;
   }
};

The PHP code

<?php
$fp = fopen ("https://finance.yahoo.com/d/quotes.csv?s=^gdaxi&f=sl1d1t1c1ohgv&e=.csv","r");
echo fgets ($fp, 1024);
fclose ($fp);
?>