[英]Losing context in knockout component
在以下示例中,我使用requirejs將組件打包為單個AMD模塊: https : //github.com/sumitkm/BuildingSpaUsingKO/tree/Part2
問題是,當它在viewmodel中調用該函數時添加click事件時,self屬性不包含viewmodel並將其指向窗口。 是什么導致此問題? 順便說一句,如果它們加載時沒有requirejs並且它們是內聯的,則不會發生此問題。
index.html的:
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Dipping your feet into KnockoutJS Components</title>
<link href="Content/bootstrap.css" rel="stylesheet" />
<link href="Content/bootstrap-theme.css" rel="stylesheet" />
</head>
<body>
<div class="navbar navbar-inverse navbar-fixed-top">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="/">KO Components</a>
</div>
</div>
</div>
<div class="container body-content" style="padding-top:50px">
<h2>Dipping your feet into KnockoutJS Components</h2>
<hr />
<greeter params='name: " Sumit!"'></greeter>
<greeter params='name: " Optimus!"'></greeter>
<greeter params='name: " Bumblebee!"'></greeter>
</div>
<footer class="navbar navbar-fixed-bottom">
<div class="container-fluid">
<p> © 2014 - Still Learning</p>
</div>
</footer>
<script src="App/boot/require.config.js"></script>
<script data-main="App/boot/startup" src="Scripts/require/require.js"></script>
</body>
</html>
require.config.js
var require = {
baseUrl: "/",
paths: {
"bootstrap": "Scripts/bootstrap/bootstrap",
"jquery": "Scripts/jquery/jquery-1.9.0",
"knockout": "Scripts/knockout/knockout-3.2.0beta.debug",
"text": "Scripts/require/text"
},
shim: {
"bootstrap": {
deps: ["jquery"]
}
}
}
startup.js
define(['jquery','knockout','bootstrap'],function($,ko){
ko.components.register('greeter', { require: 'App/components/greeter/greeting' });
ko.applyBindings();
});
greeting.html-組件模板
<div class='container-fluid'>
<div> Hello <span data-bind='text: greeting'></span></div>
<div> It is <span data-bind='text: date'></span></div>
<input type="button" value="test" data-bind="click: testClick" />
</div>
greeting.js-組件視圖模型
define([[“ nockout”,“ text!./ greeting.html”],函數(ko,greeterTemplate){
function greeterViewModel(params) {
var self = this;
self.greeting = ko.observable(params.name);
self.date = ko.observable(new Date());
self.testClick = function () {
//self is pointing to window instead of greeterViewModel
debugger;
};
}
return { viewModel: greeterViewModel, template: greeterTemplate };
});
JavaScript編譯器嘗試對閉包保持精明。 因為您的函數不使用閉包中的任何變量,所以該函數根本不包括閉包。 將代碼更改為此,您將看到它起作用:
self.testClick = function () {
console.log(self);
debugger;
};
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