how to update variable dynamically of currency rate WITH php/json/ajax - php

Question

I would like to know how to update variable dynamically of currency rate WITH php/AJAX/json that $CurrencyValue (the currency value from yahoo finance) will update only if the variable is different than it was before.
For example:
on 01/01/2016 10:00 USDINR gate was 67.454.
1/01/2016 10:01 USDINR gate was 67.104 (the variable $CurrencyValue be updated).
1/01/2016 10:02 gate of USDINR remains 67.104 (the variable $CurrencyValue not be updated).
1/01/2016 10:03 USDINR gate was 67.024 (so the variable $CurrencyValue be updated).
It is important the page will not refreshed, only the variable $CurrencyValue also if the variable changed I would like to get The exact date.
<?php
$from = 'USD'; $to = 'INR'; $url = 'http://finance.yahoo.com/d/quotes.csv?e=.csv&f=sl1d1t1&s='. $from . $to .'=X'; $currencyValue = 0; $handle = fopen($url, 'r'); if ($handle) {
while (($data = fgetcsv($handle, 1024, ',', '"')) !== FALSE)
{
$currencyValue = $data[1];
}
fclose($handle);
} $date = date('l jS \of F Y h:i:s A');
?>
Value of 1 USDINR is <?php echo $currencyValue. ' - ' .$date; ?>
Thank you
EDIT
I have a code of euro-dollar exchange via YAHOO FINANCE works with PHP / AJAX. My question is how to integrate the data released chart works with CHARTS.JS
labels: ["2016-06-02 12:41:06", "2016-06-02 12:41:08"],
datasets: [{
label: "My Third dataset - No bezier",
data: [1.1200,1.1205],
lineTension: 0,
fill: false,
}]
{"rate":"1.1200","time":"2016-06-02 12:41:06"}
{"rate":"1.1205","time":"2016-06-02 12:41:08"}
{"rate":"1.1199","time":"2016-06-02 12:41:10"}
{"rate":"1.1199","time":"2016-06-02 12:41:12"}
The Code:
<script src="Chart.bundle.min.js"></script>
<script src="http://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<style>
canvas {
-moz-user-select: none;
-webkit-user-select: none;
-ms-user-select: none;
}
</style>
<?php
if(isset($_GET['fetchOnly'])){
$from = 'eur';
$to = 'usd';
$url = 'http://finance.yahoo.com/d/quotes.csv?e=.csv&f=sl1d1t1&s='. $from . $to .'=X';
$response = array();
$handle = fopen($url, 'r');
if ($handle) {
while (($data = fgetcsv($handle, 1024, ',', '"')) !== FALSE)
{
$response['rate'] = $data[1];
$response['time'] = date("Y-m-d H:i:s");
}
fclose($handle);
}
echo json_encode($response);
die();
}
?>
<div id="responseText"></div>
<script>
// run the function, it will re-run itself
fetchRate();
function fetchRate() {
// create the new AJAX Object
xmlhttp = new XMLHttpRequest();
// this handles the request
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == XMLHttpRequest.DONE ) {
// if the request came back successfully
if(xmlhttp.status == 200){
// write the response to a div
div = document.getElementById("responseText")
div.innerHTML = div.innerHTML + '<br />'+ xmlhttp.responseText;
}else{
// if the request had an error
div.innerHTML = div.innerHTML + '<br />Error fetching rates error code : '+xmlhttp.status;
}
// rerun this function to fetch updates
setTimeout(fetchRate,1000);
}
};
// open the AJAX Object
xmlhttp.open("GET", "<?= basename(__FILE__) ?>?fetchOnly", true);
// send the AJAX request
xmlhttp.send();
}
</script>
<div style="width:100%;">
<canvas id="canvas"></canvas>
</div>
<script>
var MONTHS = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
var randomScalingFactor = function() {
return Math.round(Math.random() * 100 * (Math.random() > 0.5 ? -1 : 1));
};
var randomColorFactor = function() {
return Math.round(Math.random() * 255);
};
var randomColor = function(opacity) {
return 'rgba(' + randomColorFactor() + ',' + randomColorFactor() + ',' + randomColorFactor() + ',' + (opacity || '.3') + ')';
};
var config = {
type: 'line',
data: {
labels: ["2016-06-02 12:36:05", "2016-06-02 12:37:05"],
datasets: [{
label: "My Third dataset - No bezier",
data: [1,2],
lineTension: 0,
fill: false,
}]
},
options: {
responsive: true,
legend: {
position: 'bottom',
},
hover: {
mode: 'label'
},
scales: {
xAxes: [{
display: true,
scaleLabel: {
display: true,
labelString: 'Month'
}
}],
yAxes: [{
display: true,
scaleLabel: {
display: true,
labelString: 'Value'
}
}]
},
title: {
display: true,
text: 'Chart.js Line Chart - Legend'
}
}
};
$.each(config.data.datasets, function(i, dataset) {
var background = randomColor(0.5);
dataset.borderColor = background;
dataset.backgroundColor = background;
dataset.pointBorderColor = background;
dataset.pointBackgroundColor = background;
dataset.pointBorderWidth = 1;
});
window.onload = function() {
var ctx = document.getElementById("canvas").getContext("2d");
window.myLine = new Chart(ctx, config);
};
$('#randomizeData').click(function() {
$.each(config.data.datasets, function(i, dataset) {
dataset.data = dataset.data.map(function() {
return randomScalingFactor();
});
});
window.myLine.update();
});
$('#addDataset').click(function() {
var background = randomColor(0.5);
var newDataset = {
label: 'Dataset ' + config.data.datasets.length,
borderColor: background,
backgroundColor: background,
pointBorderColor: background,
pointBackgroundColor: background,
pointBorderWidth: 1,
fill: false,
data: [],
};
for (var index = 0; index < config.data.labels.length; ++index) {
newDataset.data.push(randomScalingFactor());
}
config.data.datasets.push(newDataset);
window.myLine.update();
});
$('#addData').click(function() {
if (config.data.datasets.length > 0) {
var month = MONTHS[config.data.labels.length % MONTHS.length];
config.data.labels.push(month);
$.each(config.data.datasets, function(i, dataset) {
dataset.data.push(randomScalingFactor());
});
window.myLine.update();
}
});
$('#removeDataset').click(function() {
config.data.datasets.splice(0, 1);
window.myLine.update();
});
$('#removeData').click(function() {
config.data.labels.splice(-1, 1); // remove the label first
config.data.datasets.forEach(function(dataset, datasetIndex) {
dataset.data.pop();
});
window.myLine.update();
});
</script>
Thank you.

Answer 1

<?php
if(isset($_GET['fetchOnly'])){
$from = 'USD';
$to = 'INR';
$url = 'http://finance.yahoo.com/d/quotes.csv?e=.csv&f=sl1d1t1&s='. $from . $to .'=X';
$response = array();
$handle = fopen($url, 'r');
if ($handle) {
while (($data = fgetcsv($handle, 1024, ',', '"')) !== FALSE)
{
$response['rate'] = $data[1];
$response['date'] = $data[2];
$response['time'] = $data[3];
}
fclose($handle);
fclose($handle);
}
echo json_encode($response);
die();
}
?>
<div id="responseText"></div>
<script>
// run the function, it will re-run itself
fetchRate();
function fetchRate() {
// create the new AJAX Object
xmlhttp = new XMLHttpRequest();
// this handles the request
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == XMLHttpRequest.DONE ) {
// if the request came back successfully
if(xmlhttp.status == 200){
// write the response to a div
div = document.getElementById("responseText")
div.innerHTML = div.innerHTML + '<br />'+ xmlhttp.responseText;
}else{
// if the request had an error
div.innerHTML = div.innerHTML + '<br />Error fetching rates error code : '+xmlhttp.status;
}
// rerun this function to fetch updates
setTimeout(fetchRate,3000);
}
};
// open the AJAX Object
xmlhttp.open("GET", "<?= basename(__FILE__) ?>?fetchOnly", true);
// send the AJAX request
xmlhttp.send();
}