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>
