使用AngularJS创建自定义的过滤器的方法

作者：bea

Angularjs过滤器是 angularjs非常棒的特性之一。有朝一日，你可能需要使用自定义过滤器，幸运的是，你找到了这篇博文。
下面显示的是自定义过滤器长什么样子(请注意myfilter):
我们的自定义过滤器叫做 "myfilter", 它有由 ':'隔开的4个参数.
这是一个将会用到的样本输入:

$scope.friends = [{name:'John', phone:'555-1276'},
{name:'Annie', phone:'800-BIG-MARY'},
{name:'Mike', phone:'555-4321'},
{name:'Adam', phone:'555-5678'},
{name:'David', phone:'555-8765'},
{name:'Mikay', phone:'555-5678'}];

过滤器只显示电话号码中含有 "555"的项，这是样本输出:

Name Phone
John 555-1276
Mike 555-4321
Adam 555-5678
David 555-8765
Mikay 555-5678

过滤"555"的处理流程由 "windowScopedFilter"执行, 它是过滤器 'myfilter'的第四个参数.
下面我们来实现这些功能 (把logging添加到每个输入参数):

var myapp = angular.module('MyFilterApp', []);
myapp.filter('myfilter', function() {
return function(input, param1) {
console.log("------------------------------------------------- begin dump of custom parameters");
console.log("input=",input);
console.log("param1(string)=", param1);
var args = Array.prototype.slice.call(arguments);
console.log("arguments=", args.length);
if (3<=args.length) {
console.log("param2(string)=", args[2]);
}
if (4<=args.length) {
console.log("param3(bool)=", args[3]);
}
console.log("------------------------------------------------- end dump of custom parameters");
// filter
if (5<=args.length) {
return window[args[4]](input);
}
return input;
};
});

上面的代码大多都log了(译者注：将信息显示到控制台). 实际完成过滤的最重要的一部分是:

// filter
if (5<=args.length) {
return window[args[4]](input);
}
return input;

"return window[args[4]](input)" 调用第四个参数, 它是 'windowScopedFilter'.
这是控制台输出:

"------------------------------------------------- begin dump of custom parameters" custom_filter_function.html:21
"input=" [object Array] custom_filter_function.html:22
"param1(string)=" "param1" custom_filter_function.html:23
"arguments=" 5 custom_filter_function.html:25
"param2(string)=" "param2" custom_filter_function.html:27
"param3(bool)=" true custom_filter_function.html:30
"------------------------------------------------- end dump of custom parameters" custom_filter_function.html:32
"------------------------------------------------- begin dump of custom parameters" custom_filter_function.html:21
"input=" [object Array] custom_filter_function.html:22
"param1(string)=" "param1" custom_filter_function.html:23
"arguments=" 5 custom_filter_function.html:25
"param2(string)=" "param2" custom_filter_function.html:27
"param3(bool)=" true custom_filter_function.html:30
"------------------------------------------------- end dump of custom parameters" custom_filter_function.html:32

完整代码:

<html>
<head>
<script src="angular.min.js"></script>
<script type="text/javascript">
function windowScopedFilter (input) {
var output = [];
angular.forEach(input, function(v,k){
if (v.phone.contains("555")) {
output.push(v);
}
});
return output;
}
var myapp = angular.module('MyFilterApp', []);
myapp.filter('myfilter', function() {
return function(input, param1) {
console.log("------------------------------------------------- begin dump of custom parameters");
console.log("input=",input);
console.log("param1(string)=", param1);
var args = Array.prototype.slice.call(arguments);
console.log("arguments=", args.length);
if (3<=args.length) {
console.log("param2(string)=", args[2]);
}
if (4<=args.length) {
console.log("param3(bool)=", args[3]);
}
console.log("------------------------------------------------- end dump of custom parameters");
// filter
if (5<=args.length) {
return window[args[4]](input);
}
return input;
};
});
myapp.controller('MyFilterController', ['$scope', function($scope) {
$scope.friends = [{name:'John', phone:'555-1276'},
{name:'Annie', phone:'800-BIG-MARY'},
{name:'Mike', phone:'555-4321'},
{name:'Adam', phone:'555-5678'},
{name:'David', phone:'555-8765'},
{name:'Mikay', phone:'555-5678'}];
}]);
</script>
</head>
<body ng-app="MyFilterApp">
<div ng-controller="MyFilterController">
<table id="searchTextResults">
<tr><th>Name</th><th>Phone</th></tr>
<tr ng-repeat="friend in friends |myfilter:'param1':'param2':true:'windowScopedFilter'">
<td>{{friend.name}}</td>
<td>{{friend.phone}}</td>
</tr>
</table>
</div>
<hr>
</body>
</html>

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使用AngularJS创建自定义的过滤器的方法

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