I have been searching for hours and can't put this to work...
This is my first website, I have a Google gauge that need to ask a database for the value that it should put on the gauge. I know how to ask the database and how to update the gauge, the problem is how should I pass the echo variable from the php file to the javascript file. (The php code need to be in a separate file or otherwise the google gauges won't display).
You can check a actual version of the website here (At the moment the gauges are static).
PHP code:
<?php
$DB_NAME = 'TSB';
$DB_HOST = 'db.tecnico.ulisboa.pt';
$DB_USER = 'xxxxxxxxx';
$DB_PASS = 'xxxxxxxxx';
$mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS);
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$mysqli->query('USE xxxxxxxxxxx;');
$result = $mysqli->query('SELECT SOC FROM TSB ORDER By time DESC LIMIT 1;');
$row = $result->fetch_array();
$soc = $row['SOC'];
echo $soc;
?>
The output of the echo is an int, or at least came as one from the database.
What I'm trying in the javascript file:
function SOC() {
var data = google.visualization.arrayToDataTable([
['Label', 'Value'],
['SOC', 0]
]);
var options = {
width: 250, height: 250,
redFrom: 0, redTo: 10,
yellowFrom: 10, yellowTo: 25,
minorTicks: 5,
majorTicks: ['0','25','50','75','100']
};
var formatter = new google.visualization.NumberFormat({
suffix: '%',
fractionDigits: 0
});
formatter.format(data, 1);
var chart = new google.visualization.Gauge(document.getElementById('SOC'));
chart.draw(data, options);
setInterval(function() {
var socPHP;
$.ajax({
url: 'soc.php',
type: 'get',
dataType:'text',
// I don't know how to properly put the $soc from php in a javascript variable
});
data.setValue(0, 1, 100); // 100 should be replaced by the value
//that came from the php file and the variable should be an INT
chart.draw( data, options);
}, 3000);
}
UPDATE After Tina Suggestion:
<?php
$DB_NAME = 'TSB';
$DB_HOST = 'db.tecnico.ulisboa.pt';
$DB_USER = 'xxxxx';
$DB_PASS = 'xxxxx';
$mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS);
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$mysqli->query('USE xxxxxx;');
$result = $mysqli->query('SELECT SOC FROM TSB ORDER By time DESC LIMIT 1;');
$row = $result->fetch_array();
$soc = $row['SOC'];
?>;
function SOC() {
var data = google.visualization.arrayToDataTable([
['Label', 'Value'],
['SOC', 0]
]);
var options = {
width: 250, height: 250,
redFrom: 0, redTo: 10,
yellowFrom: 10, yellowTo: 25,
minorTicks: 5,
majorTicks: ['0','25','50','75','100']
};
var formatter = new google.visualization.NumberFormat({
suffix: '%',
fractionDigits: 0
});
formatter.format(data, 1);
var chart = new google.visualization.Gauge(document.getElementById('SOC'));
chart.draw(data, options);
setInterval(function() {
data.setValue(0, 1, <?php echo $soc; ?>);
chart.draw( data, options);
}, 3000);
}
如果我正确理解了您的问题,请在您的javascript文件中添加所需的位置,例如,
['SOC', <?php echo $soc; ?>]
Take a look at the documentation that comes with the gauges, the data needs to be in the format: [label, value]
One way of achieving your goal is after you've sent your ajax request, you need to build an array in your php script and then use the json_encode function to output the data. You'll also need to add the parameter dataType: 'JSON'
to your ajax request.
EDIT: Its frustrating reading all the comments and seeing you not get anywhere so I wrote the following which you should be able to adapt.
You need 2 files: a HTML or PHP file containing your HTML and JS, the second needs to be a PHP file containing your database query.
File 1:
<html>
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script type="text/javascript">
google.charts.load('current', {'packages':['gauge']});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable([
['Label', 'Value'],
['Memory', 80],
['CPU', 55],
['Network', 68]
]);
var options = {
width: 400, height: 120,
redFrom: 90, redTo: 100,
yellowFrom:75, yellowTo: 90,
minorTicks: 5
};
var chart = new google.visualization.Gauge(document.getElementById('chart_div'));
chart.draw(data, options);
setInterval(function() {
$.ajax({
url: "g.php",
dataType: "JSON",
data:{},
success: function(x){
data.setValue(0, 1, x["key"]);
chart.draw(data, options);
}
});
}, 2000);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 400px; height: 120px;"></div>
</body>
</html>
File 2, g.php (This generates a random number and outputs JSON. You can put your database query here instead of the rand() function):
<?php
$data = array();
$data["key"] = rand(0,100);
print(json_encode($data));
?>
The AJAX query in the first file sends a request to file 2, g.php every 2 seconds and fetches a simple JSON object.
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