AngularJS 过滤器
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过滤器定义
可以在 AngularJS 中添加过滤器以格式化数据。AngularJS 提供了过滤器来转换数据:- currency 将数字格式化为货币格式。
- date 将日期格式化为指定的格式。
- filter 从数组中选择项的子集。
- json 将对象格式化为JSON字符串。
- limitTo 将数组/字符串限制为指定数量的元素/字符。
- lowercase 将字符串格式化为小写
- uppercase 将字符串格式设置为大写。
- number 将数字格式化为字符串
- orderBy 通过表达式对数组进行排序。
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向表达式添加过滤器
可以使用竖线字符 | 将过滤器添加到表达式中,然后使用过滤器。uppercase 过滤器将字符串格式转换为大写:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <div ng-app="myApp" ng-controller="personCtrl"> <p>姓名: {{ lastName | uppercase }}</p> </div> <script> angular.module('myApp', []).controller('personCtrl', function($scope) { $scope.firstName = "John", $scope.lastName = "Doe" }); </script> </body> </html>
lowercase 过滤器将字符串格式转换为小写:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <div ng-app="myApp" ng-controller="personCtrl"> <p>姓名: {{ lastName | lowercase }}</p> </div> <script> angular.module('myApp', []).controller('personCtrl', function($scope) { $scope.firstName = "John", $scope.lastName = "Doe" }); </script> </body> </html>
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将过滤器添加到指令
通过使用竖线字符 |,将过滤器添加到指令(例如ng-repeat),然后加上过滤器:orderBy 过滤器对数组进行排序:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <p>与对象循环:</p> <div ng-app="myApp" ng-controller="namesCtrl"> <ul> <li ng-repeat="x in names | orderBy:'country'"> {{ x.name + ', ' + x.country }} </li> </ul> </div> <script> angular.module('myApp', []).controller('namesCtrl', function($scope) { $scope.names = [ {name:'Jani',country:'Norway'}, {name:'Carl',country:'Sweden'}, {name:'Margareth',country:'England'}, {name:'Hege',country:'Norway'}, {name:'Joe',country:'Denmark'}, {name:'Gustav',country:'Sweden'}, {name:'Birgit',country:'Denmark'}, {name:'Mary',country:'England'}, {name:'Kai',country:'Norway'} ]; }); </script> </body> </html>
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currency 过滤器
currency 过滤器将数字格式化为货币:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <div ng-app="myApp" ng-controller="costCtrl"> <h1>价格: {{ price | currency }}</h1> </div> <script> var app = angular.module('myApp', []); app.controller('costCtrl', function($scope) { $scope.price = 58; }); </script> <p>currency 过滤器将数字格式化为货币格式。</p> </body> </html>
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filter 过滤器
filter 过滤器选择数组的子集。filter 过滤器只能在数组上使用,它返回仅包含匹配项的数组。下面示例返回包含字母 "i" 的名称:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <div ng-app="myApp" ng-controller="namesCtrl"> <ul> <li ng-repeat="x in names | filter : 'i'"> {{ x }} </li> <ul> </div> <script> angular.module('myApp', []).controller('namesCtrl', function($scope) { $scope.names = [ 'Jani', 'Carl', 'Margareth', 'Hege', 'Joe', 'Gustav', 'Birgit', 'Mary', 'Kai' ]; }); </script> </body> </html>
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根据用户输入过滤数组
通过在输入字段上设置ng-model
指令,我们可以将输入字段的值用作过滤器中的表达式。下面示例返回在input中输入字母,列表将根据匹配项来返回包含字母的名称:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <div ng-app="myApp" ng-controller="namesCtrl"> <p>在input框中输入字母:</p> <p><input type="text" ng-model="test"></p> <ul> <li ng-repeat="x in names | filter:test"> {{ x }} </li> <ul> </div> <script> angular.module('myApp', []).controller('namesCtrl', function($scope) { $scope.names = [ 'Jani', 'Carl', 'Margareth', 'Hege', 'Joe', 'Gustav', 'Birgit', 'Mary', 'Kai' ]; }); </script> </body> </html>
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根据用户输入对数组排序
单击表标题以更改排序顺序:名字 国家 {{x.name}} {{x.country}} 通过在表头上添加ng-click
指令,我们可以运行一个函数来更改数组的排序顺序:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <div ng-app="myApp" ng-controller="namesCtrl"> <table style="border:1px solid #333;"> <colgroup> <col width="50%"> <col width="50%"> </colgroup> <thead> <tr> <th ng-click="orderByMe('name')" style="cursor: pointer;">名字 </th> <th ng-click="orderByMe('country')" style="cursor: pointer;">国家 </th> </tr> </thead> <tbody> <tr ng-repeat="x in names | orderBy:myOrderBy"> <td>{{x.name}} </td> <td>{{x.country}} </td> </tr> </tbody> </table> </div> <script> angular.module('myApp', []).controller('namesCtrl', function($scope) { $scope.names = [ {name:'张三',country:'中国'}, {name:'Carl',country:'美国'}, {name:'Margareth',country:'英国'}, {name:'Hege',country:'澳大利亚'}, {name:'Joe',country:'西班牙'}, {name:'Gustav',country:'法国'}, {name:'Birgit',country:'日本'}, {name:'Mary',country:'英国'}, {name:'李四',country:'中国'} ]; $scope.orderByMe = function(x) { $scope.myOrderBy = x; } }); </script> </body> </html>
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自定义过滤器
您可以通过在 module(模块) 中注册新的过滤器工厂功能来制作自己的过滤器。创建一个名为 "myFormat" 的自定义过滤器:<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>菜鸟教程(cainiaoya.com)</title> <script src="//cdn.bootcss.com/angular.js/1.5.8/angular.min.js"></script> </head> <body> <ul ng-app="myApp" ng-controller="namesCtrl"> <li ng-repeat="x in names"> {{x | myFormat}} </li> <ul> <script> var app = angular.module('myApp', []); app.filter('myFormat', function() { return function(x) { var i, c, txt = ""; for (i = 0; i < x.length; i++) { c = x[i]; if (i % 2 == 0) { c = c.toUpperCase(); } txt += c; } return txt; }; }); app.controller('namesCtrl', function($scope) { $scope.names = ['Jani', 'Carl', 'Margareth', 'Hege', 'Joe', 'Gustav', 'Birgit', 'Mary', 'Kai']; }); </script> </body> </html>
myFormat 筛选器会将所有不是2的百分余数的字符格式化为大写。
有关过滤器的更多信息,请到我们的 AngularJS 参考手册 中阅读