[英]Google Line Chart - Refresh database automatically
我正在使用一個界面,該界面顯示了通過Google折線圖從數據庫中檢索到的數據。 但是,新數據每10秒存儲在我的數據庫中,並且我無法自動刷新圖表。
我需要一些非常基礎的東西,並且我已經在互聯網上看過。 我讀了一些有關Javascript / AJAX / JQuery的信息...但是我對Hardware:D更滿意
這是我的文件EDIT:Chart_get和主文件已根據@Michel的答案進行了修改。
fetch.php-獲取數據並回顯
<?php // Connection and Request stuff
$host = blablabla
(...)
$req = $bdd->query('SELECT id, battery FROM Station');
while ($data = $req->fetch()){
$id = addslashes($data['id']);
$charge_batt = intval($data['charge_batt']);
$result .= "['".$id."' , ".$charge_batt."],";
}
$result = substr($result, 0, -1); // Erase the last ","
echo $result;
?>
輸出:
['1' , 90],['2' , 89],['3' , 80],['4' , 100],['5' , 90],['6' , 50],['7' , 67]
chart_get.php-初始化圖表並使用“ echo $ result”數據進行繪制
<script type="text/javascript" src="//www.google.com/jsapi"></script>
<script type="text/javascript">
google.load("visualization", "1", {packages:["corechart"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable([
<?php
echo ("['Date', 'Battery'],");
include('fetch.php');
?>
]);
var options = {
title: 'Battery health',
animation:{
duration: 1000,
easing: 'out',
},
curveType: 'function'
};
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
為了刷新“ chart_div”,我嘗試了:
main.html-具有加載功能的jQuery腳本
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="fr" lang="fr">
<head>
<title>Project - Chart</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<script type="text/javascript" src="jQuery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
// first load it once, so it display's the chart
$('#tableHolder').load('chart_get.php');
// then execute the interval
setInterval(function(){$('#tableHolder').load('chart_get.php');}, 5000);
});
</script>
</head>
<body>
<p>Hello</p>
<div id="tableHolder"> </div>
</body>
</html>
但是該圖表根本不顯示。 我完全不知道我在做什么錯。 我正在快速閱讀有關javascript的一些教程,但是如果您知道如何解決我的問題,對您有所幫助將是非常棒的:) 謝謝!
OP的解決方案。
我找到了答案!
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="fr" lang="fr">
<head>
<title>Projet GreenFeed - Station de recharge a energie positive</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
<script type="text/javascript">
// Load the Visualization API and the piechart package.
google.load('visualization', '1', {'packages':['corechart']});
// Set a callback to run when the Google Visualization API is loaded.
google.setOnLoadCallback(drawChart);
function drawChart() {
//AJAX Call is compulsory !
var jsonData = $.ajax({
url: "chart_fetch.php",
dataType:"json",
async: false
}).responseText;
// Create our data table out of JSON data loaded from server.
var data = new google.visualization.DataTable(jsonData);
var options = {
title: 'Battery',
is3D: 'true',
width: 800,
height: 600
};
// Instantiate and draw our chart, passing in some options.
// Do not forget to check your div ID
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
<script type="text/javascript" src="jQuery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
// First load the chart once
drawChart();
// Set interval to call the drawChart again
setInterval(drawChart, 5000);
});
</script>
</head>
<body>
<div id="chart_div"> </div>
</body>
</html>
首先刪除chart_get.php中的<!DOCTYPE>
, <html>
, <head>
, <meta>
和<title>
標記。
如果您不希望刷新, chart_get.php
中的數據與<div id="tableHolder"></div>
的數據相同。
其次,將main.html
的腳本重寫為此:
<script type="text/javascript">
$(document).ready(function(){
// first load it once, so it display's the chart
// (otherwise you have to wait 5 seconds)
$('#tableHolder').load('chart_get.php');
// then execute the interval
setInterval(function(){$('#tableHolder').load('chart_get.php');}, 5000);
});
</script>
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