我一直试图让this jsfiddle工作。到目前为止没有运气。
我编写（复制）的HTML
<!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">
<head>
<meta name="generator" content=
"HTML Tidy for Linux/x86 (vers 11 February 2007), see www.w3.org" />
<!-- add some head tags here -->
<title>Try</title>
<script src="http://code.jquery.com/jquery-1.7.2.min.js" type="text/javascript">
</script>
<script type="text/javascript" src=
"http://rniemeyer.github.com/KnockMeOut/Scripts/knockout-latest.debug.js">
</script>
<script type="text/javascript" src="static/js/knockout.mapping.js">
</script>
<style type="text/css">
/*<![CDATA[*/
body, a, p { font-size: .85em; }
input { width: 100px; }
table { border: 1px solid black; }
h3, p, td, th { padding: 3px; }
h3 { font-weight: bold; }
.matched { background-color: yellow; }
.n { text-align: right; }
/*]]>*/
</style>
</head>
<body>
<script type="text/javascript" src="static/js/array_mapping.js">
</script><script type="text/javascript" src=
"https://raw.github.com/jquery/jquery-tmpl/master/jquery.tmpl.min.js">
</script>
<h3>1- JSON string from server</h3>
<p data-bind="text: JSONdataFromServer"></p>
<h3>2- Converted to an object with ko.parseJSON</h3>
<p data-bind="text: ko.toJSON(dataFromServer)"></p>
<h3>3- Mapped to use observables and add a dependentObservable</h3>
<p data-bind="text: ko.toJSON(mappedData)"></p>
<hr />
<h3>4- Display in an editor</h3><script id="itemsTmpl" type="text/html">
<![CDATA[
<tr data-bind="css: { matched: $data === viewModel.firstMatch() }">
<td>
<input data-bind="value: name" />
</td>
<td>
<select data-bind="options: viewModel.categories, value: category"></select>
</td>
<td>
<input class="n" data-bind="value: price" />
</td>
<td class="n" data-bind="text: priceWithTax">
</td>
<td>
<a href="javascript: void(0);" data-bind="click: function() { viewModel.removeItem($data); }">Delete</a>
</td>
</tr>
]]>
</script>
<table id="mytable" data-bind="triggerUpdate: items">
<thead>
<tr>
<th>Name</th>
<th>Category</th>
<th>Price</th>
<th>w/Tax</th>
<th></th>
</tr>
</thead>
<tr>
<td><a href="javascript:%20void(0);" data-bind="click: addItem">Add Item</a></td>
<td></td>
<td class="n">Total:</td>
<td class="n" data-bind="text: total"></td>
<td></td>
</tr>
</table>
<h3>5- Filter display by name</h3>
<p>Filter: <input data-bind="value: filter, valueUpdate: 'afterkeydown'" /></p>
<h3>6- Find first match by name</h3>
<p>Search: <input data-bind="value: search, valueUpdate: 'afterkeydown'" /></p>
<hr />
<h3>7- Use ko.utils.arrayMap to build an array with just categories used</h3>
<p data-bind="text: ko.toJSON(viewModel.justCategories)"></p>
<h3>8- Use ko.utils.arrayGetDistinctValues to get just the unique categories used</h3>
<p data-bind="text: ko.toJSON(viewModel.uniqueCategories)"></p>
<h3>9- Use ko.utils.compareArrays to find available categories that haven't been
used</h3>
<p data-bind="text: ko.toJSON(viewModel.missingCategories)"></p>
<h3>10- Convert items to JSON</h3>
<p data-bind="text: ko.toJSON(viewModel.items)"></p>
<h3>11- Map items to send back to server and convert to JSON</h3>
<p data-bind="text: ko.toJSON(viewModel.mappedItems)"></p>
</body>
</html>
javascript位于一个名为array_mapping.js的文件中，看起来像这样
function Item(name, category, price) {
this.name = ko.observable(name);
this.category = ko.observable(category);
this.price = ko.observable(price);
this.priceWithTax = ko.dependentObservable(function() {
return (this.price() * 1.05).toFixed(2);
}, this);
}
var viewModel = {
categories: ["Bread", "Dairy", "Fruits", "Vegetables"],
items: ko.observableArray([]),
filter: ko.observable(""),
search: ko.observable(""),
addItem: function() {
this.items.push(new Item("New", "", 1));
},
removeItem: function(item) {
this.items.remove(item);
}
};
//ko.utils.arrayFilter - filter the items using the filter text
viewModel.filteredItems = ko.dependentObservable(function() {
var filter = this.filter().toLowerCase();
if (!filter) {
return this.items();
} else {
return ko.utils.arrayFilter(this.items(), function(item) {
return ko.utils.stringStartsWith(item.name().toLowerCase(), filter);
});
}
}, viewModel);
//ko.utils.arrayForEach - return a total by adding all prices
viewModel.total = ko.dependentObservable(function() {
var total = 0;
ko.utils.arrayForEach(this.filteredItems(), function(item) {
var value = parseFloat(item.priceWithTax());
if (!isNaN(value)) {
total += value;
}
});
return total.toFixed(2);
}, viewModel);
//ko.utils.arrayFirst - identify the first matching item by name
viewModel.firstMatch = ko.dependentObservable(function() {
var search = this.search().toLowerCase();
if (!search) {
return null;
} else {
return ko.utils.arrayFirst(this.filteredItems(), function(item) {
return ko.utils.stringStartsWith(item.name().toLowerCase(), search);
});
}
}, viewModel);
//ko.utils.arrayMap - get a list of used categories
viewModel.justCategories = ko.dependentObservable(function() {
var categories = ko.utils.arrayMap(this.items(), function(item) {
return item.category();
});
return categories.sort();
}, viewModel);
//ko.utils.arrayGetDistinctValues - get a unique list of used categories
viewModel.uniqueCategories = ko.dependentObservable(function() {
return ko.utils.arrayGetDistinctValues(viewModel.justCategories()).sort();
}, viewModel);
//ko.utils.compareArrays - find any unused categories
viewModel.missingCategories = ko.dependentObservable(function() {
//find out the categories that are missing from uniqueNames
var differences = ko.utils.compareArrays(viewModel.categories, viewModel.uniqueCategories());
//return a flat list of differences
var results = [];
ko.utils.arrayForEach(differences, function(difference) {
if (difference.status === "deleted") {
results.push(difference.value);
}
});
return results;
}, viewModel);
//ko.utils.arrayMap - prepare items to be sent back to server
viewModel.mappedItems = ko.dependentObservable(function() {
var items = ko.toJS(this.items);
return ko.utils.arrayMap(items, function(item) {
delete item.priceWithTax;
return item;
});
}, viewModel);
//a JSON string that we got from the server that wasn't automatically converted to an object
var JSONdataFromServer = '[{"name":"Peach","category":"Fruits","price":1},{"name":"Plum","category":"Fruits","price":0.75},{"name":"Donut","category":"Bread","price":1.5},{"name":"Milk","category":"Dairy","price":4.50}]';
//parse into an object
var dataFromServer = ko.utils.parseJson(JSONdataFromServer);
//do some basic mapping (without mapping plugin)
var mappedData = ko.utils.arrayMap(dataFromServer, function(item) {
return new Item(item.name, item.category, item.price);
});
viewModel.items(mappedData);
ko.applyBindings(viewModel);
脚本部分中的所有链接都正常工作。但我无法得到理想的结果。
我注意到如果我在框架菜单上尝试其他任何选项（例如onLoad），代码也不会在jsfiddle上运行。这可能是个原因吗？
答案 0 :(得分：0)
HTML中引用viewModel的任何绑定都将其用作全局变量。所以，当你做onLoad时，它不会是全局的。使用KO 2.0，您现在可以将viewModel替换为$root，而viewModel则不需要是全局的。我会从https://github.com/downloads/SteveSanderson/knockout/knockout-2.0.0.debug.js
此外，任何调用ko.applyBindings的代码都应放在页面底部或类似jQuery＆＃34; ready＆＃34;功能，因为它需要完整的DOM。因此，您可以将外部js文件放在页面底部。