Ember.js:在模板中呈现谷歌图表(仅当存在时才称为目标DOM元素)
Ember.js: rendering google chart in template (AKA target DOM element only when present)
我正在尝试将一个正在运行的谷歌图表示例集成到我的ember.js应用程序中。问题是,我不确定把drawChart()
函数放在哪里,这样只有当它的目标DOM元素在页面上时才能运行它。
- Ember应用程序示例:http://jsbin.com/oqeSabI/4/edit
- 工作谷歌图表示例:http://jsfiddle.net/doub1ejack/h7mSQ/96/
我认为加载函数的正确位置在视图中(我看不出有任何理由将其放在模型/控制器/路线中)。但我需要确保drawChart()
在模板完成渲染并且<div id='chart'>
元素存在之后才会被调用。
显然View.init()
太早了我应该在哪里调用构建函数
它甚至属于一个视图吗(也许我应该使用控制或把手助手?)
App.DashboardView = Ember.View.extend({
name: "",
init: function(){
// this breaks the app...
//google.load("visualization", "1", {packages:["corechart"]});
//google.setOnLoadCallback(drawBarGraph);
this.set('name', 'ted');
return this._super();
}
});
最好将与ui和布局相关的逻辑放在views
中。因此,对于这个任务,我建议使用view
或component
。正如您已经意识到的那样,didInsertElement
事件是调用这种逻辑的合适位置,因为您需要确保视图已插入到DOM中,并且所有必需的元素(如div#chart
)都可用。
我提供的解决方案有点粗糙,但给出了一个起点。
其想法是创建一个可重用视图GoogleChartView
,该视图具有可包含在任何其他视图中的相关模板google-chart
。我假设仪表板视图最终也会包括其他图表,这些图表将使用其模型在图表、表格等中显示数据。此图表相关视图是在视图助手{{view "googleChart"}}
的帮助下包含的。另一个重要的点是google.load
需要在头中调用。
http://jsbin.com/oCIcexOB/1/edit
JS
App = Ember.Application.create();
/******** VIEWS ********/
App.DashboardView = Ember.View.extend({
name: "",
init: function(){
//google.load("visualization", "1", {packages:["corechart"]});
//google.setOnLoadCallback(drawBarGraph);
this.set('name', 'ted');
return this._super();
}
});
App.GoogleChartView = Ember.View.extend({
templateName:"google-chart",
drawChart:function(){
drawChart();
}.on("didInsertElement")
});
/******** ROUTES ********/
App.Router.map(function() {
this.resource('items');
this.resource('dashboard');
});
App.IndexRoute = Ember.Route.extend({
redirect: function() {
this.transitionTo('items');
}
});
App.ItemsRoute = Ember.Route.extend({
model: function() {
var a = Em.A();
a.pushObject( App.Item.create({title: 'A', cost: '100', options: buildMockOptions('A')}));
a.pushObject( App.Item.create({title: 'B', cost: '200', options: buildMockOptions('B')}));
a.pushObject( App.Item.create({title: 'C', cost: '300', options: buildMockOptions('C')}));
return a;
}
});
buildMockOptions = function(someVar){
var arr = [];
for(var i = 0;i<3;i++){
var opt = App.Option.create({someOption: 'Option for ' + someVar + ': ' + i});
opt.cost = 5;
arr.pushObject(opt);
}
return arr;
};
/******** MODELS ********/
App.Item = Ember.Object.extend({
title: '',
cost: '',
quantity: '',
options: null,
totalOptionsCost: function(){
var j = this.get('options').reduce(
function(prevValue, currentValue, index, array){
return prevValue + parseInt(currentValue.get('cost'), 10); }, 0);
return j;
}.property('options.@each.cost')
});
App.Option = Ember.Object.extend({
someOption: '',
cost: ''
});
/******** CONTROLLERS ********/
App.ItemsController = Ember.ArrayController.extend({
len: function(){
return this.get('length');
}.property('length'),
totalCost: function() {
return this.reduce( function(prevCost, cost){
return parseInt(cost.get('cost'),10) + prevCost;
}, 0);
}.property('@each.cost'),
totalOptions: function(){
var opts = this.mapBy('options');
return [].concat.apply([], opts).length;
}.property(),
totalOptionCost: function(){
var sum = this.reduce(function(prev, curr){
return prev + curr.get('totalOptionsCost');},0);
return sum;
}.property('@each.totalOptionsCost')
});
App.DashboardController = Em.Controller.extend({
needs: ['items'],
itemsLength: Ember.computed.alias('controllers.items.len'),
itemsTotalCost: Ember.computed.alias('controllers.items.totalCost'),
optionsTotal: Ember.computed.alias('controllers.items.totalOptions'),
optionsCost: Ember.computed.alias('controllers.items.totalOptionCost')
});
// GOOGLE CHART FUNCTION
function drawChart() {
// Create and populate the data table.
var options = {
title:"Yearly Coffee Consumption",
width:600,
height:400,
animation: {duration: 1000, easing: 'out'},
vAxis: {title: "Cups", minValue:0, maxValue:500},
hAxis: {title: "Year"}
};
var data = new google.visualization.DataTable();
data.addColumn('string', 'N');
data.addColumn('number', 'Value');
data.addRow(['2003', 0]);
data.addRow(['2004', 0]);
data.addRow(['2005', 0]);
// Create and draw the visualization.
var chart = new google.visualization.ColumnChart(document.getElementById('chart'));
chart.draw(data, options);
data.setValue(0, 1, 400);
data.setValue(1, 1, 300);
data.setValue(2, 1, 400);
chart.draw(data, options);
var button = document.getElementById('b1');
button.onclick = function() {
if (data.getNumberOfRows() > 5) {
data.removeRow(Math.floor(Math.random() * data.getNumberOfRows()));
}
// Generating a random x, y pair and inserting it so rows are sorted.
var x = Math.floor(Math.random() * 10000);
var y = Math.floor(Math.random() * 1000);
var row = 0;
while (row < data.getNumberOfRows() && parseInt(data.getValue(row, 0),10) < x) {
row++;
}
data.insertRows(row, [[x.toString(), y]]);
chart.draw(data, options);
};
}
function drawChart() {
// Create and populate the data table.
var options = {
title:"Yearly Coffee Consumption",
width:600,
height:400,
animation: {duration: 1000, easing: 'out'},
vAxis: {title: "Cups", minValue:0, maxValue:500},
hAxis: {title: "Year"}
};
var data = new google.visualization.DataTable();
data.addColumn('string', 'N');
data.addColumn('number', 'Value');
data.addRow(['2003', 0]);
data.addRow(['2004', 0]);
data.addRow(['2005', 0]);
// Create and draw the visualization.
var chart = new google.visualization.ColumnChart(document.getElementById('chart'));
chart.draw(data, options);
data.setValue(0, 1, 400);
data.setValue(1, 1, 300);
data.setValue(2, 1, 400);
chart.draw(data, options);
var button = document.getElementById('b1');
button.onclick = function() {
if (data.getNumberOfRows() > 5) {
data.removeRow(Math.floor(Math.random() * data.getNumberOfRows()));
}
// Generating a random x, y pair and inserting it so rows are sorted.
var x = Math.floor(Math.random() * 10000);
var y = Math.floor(Math.random() * 1000);
var row = 0;
while (row < data.getNumberOfRows() && parseInt(data.getValue(row, 0),10) < x) {
row++;
}
data.insertRows(row, [[x.toString(), y]]);
chart.draw(data, options);
};
}
HTML
<!DOCTYPE html>
<html>
<head>
<meta name="description" content="Ember.js example: Trying to display a google chart in a template." />
<meta charset=utf-8 />
<title>JS Bin</title>
<script src="http://www.google.com/jsapi?ext.js"></script>
<script src="http://code.jquery.com/jquery-2.0.2.js"></script>
<script src="http://builds.emberjs.com/handlebars-1.0.0.js"></script>
<script src="http://builds.emberjs.com/ember-latest.js"></script>
<script src="http://www.google.com/jsapi?ext.js"></script>
<script>google.load("visualization", "1", {packages:["corechart"]});</script>
</head>
<body>
<script type="text/x-handlebars" data-template-name="application">
<p><strong>Ember.js example:</strong><br> Trying to display a google chart in a template.</p>
<p>This jsbin represents a dashboard that analyzes a hierarchy of items and child 'options' and visualizes that info in a 'dashboard' section'. Currently, I am trying to integrate a google chart into the dashboard right above the 'Change Value' button.</p>
<p>Google chart example: <a href='http://jsfiddle.net/doub1ejack/h7mSQ/96/'>http://jsfiddle.net/doub1ejack/h7mSQ/96/</a><br>
Stackoverflow post: <a href='http://stackoverflow.com/questions/20198317/ember-js-rendering-google-chart-in-template-aka-target-dom-element-only-when-p'>http://stackoverflow.com/questions/20198317/...</a></p>
{{render dashboard}}
{{outlet}}
</script>
<script type="text/x-handlebars" data-template-name="items">
<h2>Items:</h2>
<dl>
{{#each}}
<dt>Item: {{title}}</dt>
<dd>Cost: {{cost}}</dd>
<dd class='options'>{{render 'options' options}}</dd>
{{/each}}
</dl>
</script>
<script type="text/x-handlebars" data-template-name="options">
{{log controller}}
<dl>
{{#each option in controller }}
<dt>{{option.someOption}}</dt>
<dd>Option cost: {{option.cost}}</dd>
{{/each}}
</dl>
</script>
<script type="text/x-handlebars" data-template-name="dashboard">
<h2>Dashboard:</h2>
{{view "googleChart"}}
<div id="chart"></div>
{{! ITEM/OPTION ANALYSIS }}
{{#if controllers.items}}
<h3>Item Overview:</h3>
Total number of items (expect 3): {{itemsLength}}<br>
Total cost of items (expect 600): {{itemsTotalCost}}
<h3>Option Overview:</h3>
Total number of options (expect 30): {{optionsTotal}}<br>
Total cost of options (expect 45): {{optionsCost}}
{{/if}}
</script>
<script type="text/x-handlebars" data-template-name="google-chart">
<div id="chart"></div>
<form><input id="b1" type="button" value="Change Value"/></form>
</script>
</body>
</html>
编辑
这是另一个例子,其中具有与绘制图表相关的属性和数据的代码被容纳在GoogleChartView
类中,允许绑定属性、执行操作等。这也是一个示例草案,只是为了演示这个想法。change-value操作执行旧代码,但它肯定可以修改GoogleChartView的数据属性。GoogleChartView的数据属性当然可以更好地利用该模型。有趣的一点是通过this.$().find
检索视图的DOM,访问包含该视图的上下文的控制器(DashboardController),因为此时可以检索、解析和绘制任何数据。
http://jsbin.com/UHajoX/1/edit
App.GoogleChartView = Ember.View.extend({
templateName:"google-chart",
chart:null,
options:{
title:"Yearly Coffee Consumption",
width:600,
height:400,
animation: {duration: 1000, easing: 'out'},
vAxis: {title: "Cups", minValue:0, maxValue:500},
hAxis: {title: "Year"}
},
data:function(){
var items = this.get("controller").get("items");
var chartData = new google.visualization.DataTable();
chartData.addColumn('string', 'N');
chartData.addColumn('number', 'Value');
chartData.addRow(['2003', 0]);
chartData.addRow(['2004', 0]);
chartData.addRow(['2005', 0]);
items.forEach(function(item,index){
chartData.setValue(index,1,parseInt(item.get("cost"),10));
});
/*chartData.setValue(0, 1, 400);
chartData.setValue(1, 1, 300);
chartData.setValue(2, 1, 400);*/
return chartData;
}.property(),
drawChart:function(){
this.drawChart2();
}.on("didInsertElement"),
drawChart2:function(){
var data = this.get("data");
// Create and draw the visualization.
this.set("chart", new google.visualization.ColumnChart(this.$().find('#chart').get(0)));
this.get("chart").draw(data, this.get("options"));
},
actions:{
changeValue:function(){
var data = this.get("data");
if (data.getNumberOfRows() > 5) {
data.removeRow(Math.floor(Math.random() * data.getNumberOfRows()));
}
// Generating a random x, y pair and inserting it so rows are sorted.
var x = Math.floor(Math.random() * 10000);
var y = Math.floor(Math.random() * 1000);
var row = 0;
while (row < data.getNumberOfRows() && parseInt(data.getValue(row, 0),10) < x) {
row++;
}
data.insertRows(row, [[x.toString(), y]]);
this.set("data",data);
this.get("chart").draw(data, this.get("options"));
}
}
});
警告:我想未来数据可能来自ember应用程序本身,但现在调用谷歌加载时,视图可能会尝试调用drawChart,但数据还不可用。为了克服这个问题,您可能需要在调用drawChart之前检查数据是否已加载。
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