[英]“Uncaught ReferenceError: chart is not defined”
所有,
我正在使用以下HTML / Javascript代碼:
<!doctype html>
<html>
<head>
<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<!-- google fonts from CDN -->
<link href='http://fonts.googleapis.com/css?family=Open+Sans:400,300,600' rel='stylesheet' type='text/css'>
<!-- highcharts -->
<script src="http://code.highcharts.com/highcharts.js"></script>
<style>
html, body {
width: 95%;
margin: auto;
font-family: 'Open Sans',sans-serif;
}
#chart_container {
width:100%;
height:500px;
}
</style>
</head>
<body>
<h1>Live Data</h1>
<div id="chart_container">
</div>
</body>
<script type="text/javascript">
$(document).ready(function() {
chart = new Highcharts.Chart({
chart: {
renderTo: 'chart_container',
defaultSeriesType: 'line',
events: {
load: getBirds
}
},
title: {
text: 'DRHW Live Data Stream'
},
xAxis: {
type: 'datetime',
tickPixelInterval: 150,
maxZoom: 20 * 1000
},
yAxis: {
title: {
text: 'Count Observed'
}
},
series: [
],
legend: {
layout: 'horiztonal',
align: 'center'
}
});
function getBirds() {
var now = new Date();
var et = now.getTime() / 1000; //PHP TS
var st = et - 10; //30 seconds prior in PHP
console.log(chart);
if (chart.series.length > 0) {
var series = chart.series[0];
var length = series.length + 1;
var shift = series.data.length > 20;
}
$.getJSON("https://path/to/json&callback=?", function(result) {
var data = result.data;if (data.length == 0) {
return;
} else {
additions = new Array();
for (i=0;i<data.length;i++) {
if (data[i].qstype != "1") {
species = data[i].answers[0]['answer'];
scode = species.substring(0,species.search(" - ")).trim()
count = (data[i].answers[1]['answer'] * 1);
newdata = new Object();
newdata['name'] = species;
newdata['count'] = count;
additions.push(newdata);
}
}
//now, for each addition, you need to loop through the existing data structures, and see if the thing exists. if it does, add the data; if not, add the thing, then add the data.
var existingdata = chart.series;
for (i=0;i<additions.length;i++) {
isnewpoint = true;
for (j=0;j<existingdata.length;j++) {
if (existingdata[j].name == additions[i].name) {
isnewpoint = false
count = additions[i].count;
point = [now.getTime(),count];
chart.series[j].addPoint(point, true, shift);
shift = false; //this way, only one shift occurs - the first time through adding a new point to an existing data set. this will control against future shifting, either from other datapoints having new points added,
}
}
if (isnewpoint) {
newseries = new Object();
count = additions[i].count;
newseries['name'] = additions[i].name;
for (j=0;j<length;j++) {
newseries['data'].push(0);
}
newseries['data'].push(count);
chart.series.push(newseries);
}
}
//we have now looped through and added a new data point to all species where new data was created in this pull. We still need to add a new point to those that were not affected.
existingdata = chart.series;
for (i=0;i<existingdata.length;i++) {
getname = existingdata[i].name;
getlength = existingdata[i].data.length;
if (getlength<length) { //which we established earlier as one MORE than existed previously, prior to the addition
point = [now.getTime(),0]
chart.series[i].addPoint(point, true, shift);
}
}
}
setTimeout(getBirds,10000);
});
}
});
</script>
</html>
我遇到的問題非常簡單(但讓我瘋了!),並且在js區塊的早期。 雖然我將變量'chart'定義為新的Highcharts圖表,並且我將'getBirds'設置為加載后加載的函數,但console.log行告訴我圖表未定義,並且下面的行它拋出一個錯誤( Uncaught TypeError: Cannot read property 'series' of undefined
)。
我檢查過以下內容:
chart
變量(當然為我的console.log定義了圖表,但沒有定義下一行所需的chart.series
); getBirds()
函數放在chart
定義之上。 我不知所措。 提供任何幫助非常感謝; 提前致謝!
原因很可能是您在聲明階段不能引用變量。 我猜測正在聲明加載函數被調用。 幸運的是,您可以在函數聲明期間引用該對象。 請嘗試以下代碼塊。
function getBirds(e) {
var now = new Date(),
et = now.getTime() / 1000, //PHP TS
st = et - 10, //30 seconds prior in PHP
chart = this;
if (chart.series.length > 0) {
...在var塊里面聲明chart
變量。
從高亮度頁面嘗試示例我發現變量chart
只有在$.json()
或$ajax()
調用之后才可用。 如果您在此之前嘗試使用chart
,則返回undefined
。 因為它是,它只在$ .json()之后設置。
他們使用json或ajax的示例是這樣設置的:
var chart;
function requestData() {...}
$(document).ready(function() {
chart = new Highcharts.Chart({
chart: {
renderTo: 'chart_container',
defaultSeriesType: 'spline',
events: {
load: requestData
}
...
});
我和你的例子做了類似的事情。 從getBirds()
我在json調用之前注釋掉了一些行:
console.log(chart);
if (chart.series.length > 0) {
var series = chart.series[0];
var length = series.length + 1;
var shift = series.data.length > 20;
}
並在json召喚之后移動它們。
並改變了這一行:
//newdata['name'] = species;
newdata['name'] = scode;
並停在這里:
for (j=0;j<length;j++) {
因為錯誤:
Uncaught TypeError: Cannot call method 'push' of undefined
在線
newseries['data'].push(count);
它失敗,因為沒有數組。 希望這有幫助。
在全局命名空間中存在圖表對象之前解釋函數聲明 。
如果您將語法更改為函數表達式
var getBirds=function() {
....
};
在你打電話之前不會對它進行評估。
但是,您可能希望將圖表添加為getBirds()的參數,它比從全局命名空間獲取變量要便宜一些。
編輯
這可能需要一些調試,但值得一試
var getBirds = function(chart) {
...
};
$(document).ready(function() {
chart = new Highcharts.Chart({
chart: {
renderTo: 'chart_container',
defaultSeriesType: 'line',
events: {
load: function() {
getBirds(this);
}
}
}
...
});
setTimeout(getBirds,10000);
});
}
});
你應該檢查兩個解決方案:
系列變量屬性不應該是空數組也許可以輸入系列:null;
用這段代碼替換你的腳本並再次檢查:
http://notepad.cc/share/3TwgCoEano
<script type="text/javascript">
$(function() {
$(document).ready(function() {
var chart = new Highcharts.Chart({
chart: {
renderTo: 'chart_container',
defaultSeriesType: 'line',
events: {
load: getBirds
}
},
title: {
text: 'DRHW Live Data Stream'
},
xAxis: {
type: 'datetime',
tickPixelInterval: 150,
maxZoom: 20 * 1000
},
yAxis: {
title: {
text: 'Count Observed'
}
},
series: null,
legend: {
layout: 'horiztonal',
align: 'center'
}
});
function getBirds() {
var now = new Date();
var et = now.getTime() / 1000; //PHP TS
var st = et - 10; //30 seconds prior in PHP
console.log(chart);
if (chart.series.length > 0) {
var series = chart.series[0];
var length = series.length + 1;
var shift = series.data.length > 20;
}
$.getJSON("https://path/to/json&callback=?", function(result) {
var data = result.data;if (data.length == 0) {
return;
} else {
additions = new Array();
for (i=0;i<data.length;i++) {
if (data[i].qstype != "1") {
species = data[i].answers[0]['answer'];
scode = species.substring(0,species.search(" - ")).trim()
count = (data[i].answers[1]['answer'] * 1);
newdata = new Object();
newdata['name'] = species;
newdata['count'] = count;
additions.push(newdata);
}
}
//now, for each addition, you need to loop through the existing data structures, and see if the thing exists. if it does, add the data; if not, add the thing, then add the data.
var existingdata = chart.series;
for (i=0;i<additions.length;i++) {
isnewpoint = true;
for (j=0;j<existingdata.length;j++) {
if (existingdata[j].name == additions[i].name) {
isnewpoint = false
count = additions[i].count;
point = [now.getTime(),count];
chart.series[j].addPoint(point, true, shift);
shift = false; //this way, only one shift occurs - the first time through adding a new point to an existing data set. this will control against future shifting, either from other datapoints having new points added,
}
}
if (isnewpoint) {
newseries = new Object();
count = additions[i].count;
newseries['name'] = additions[i].name;
for (j=0;j<length;j++) {
newseries['data'].push(0);
}
newseries['data'].push(count);
chart.series.push(newseries);
}
}
//we have now looped through and added a new data point to all species where new data was created in this pull. We still need to add a new point to those that were not affected.
existingdata = chart.series;
for (i=0;i<existingdata.length;i++) {
getname = existingdata[i].name;
getlength = existingdata[i].data.length;
if (getlength<length) { //which we established earlier as one MORE than existed previously, prior to the addition
point = [now.getTime(),0]
chart.series[i].addPoint(point, true, shift);
}
}
}
setTimeout(getBirds,10000);
});
}
});
});
</script>
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