zoukankan      html  css  js  c++  java
  • anagularJs指令的controller,link,compile有什么不同

    /directives.js增加exampleDirective  
    phonecatDirectives.directive('exampleDirective', function() {  
        return {  
            restrict: 'E',  
            template: '<p>Hello {{number}}!</p>',  
            controller: function($scope, $element){  
                $scope.number = $scope.number + "22222 ";  
            },  
            link: function(scope, el, attr) {  
                scope.number = scope.number + "33333 ";  
            },  
            compile: function(element, attributes) {  
                return {  
                    pre: function preLink(scope, element, attributes) {  
                        scope.number = scope.number + "44444 ";  
                    },  
                    post: function postLink(scope, element, attributes) {  
                        scope.number = scope.number + "55555 ";  
                    }  
                };  
            }  
        }  
    });  
      
    //controller.js添加  
    dtControllers.controller('directive2',['$scope',  
        function($scope) {  
            $scope.number = '1111 ';  
        }  
    ]);  
      
    //html  
    <body ng-app="phonecatApp">  
        <div ng-controller="directive2">  
            <example-directive></example-directive>  
        </div>  
    </body>  

    运行结果:

     Hello 1111 22222 44444 55555 ! 

    由结果可以看出来,controller先运行,compile后运行,link不运行 (link就是compile中的postLink)

    将上例中的compile注释掉

    //        compile: function(element, attributes) {  
    //            return {  
    //                pre: function preLink(scope, element, attributes) {  
    //                    scope.number = scope.number + "44444 ";  
    //                },  
    //                post: function postLink(scope, element, attributes) {  
    //                    scope.number = scope.number + "55555 ";  
    //                }  
    //            };  
    //        }  

    运行结果:

    Hello 1111 22222 33333 ! 

    由结果可以看出来,controller先运行,link后运行,link和compile不兼容。

    <div ng-controller="ctrl1">
        <superman weight length speed>superman</superman>
        <superman weight >weight</superman>
    </div>
     
    <script type="text/javascript">
        angular.module('myMoudle',[])
                .controller('ctrl1', ['$scope', function($scope){
     
                }])
                .directive("superman", function(){
                    return {
                        restrict : "E",
                        scope : {},
                        controller : function($scope){
                            $scope.abilities = [];
     
                            this.addWeight = function(){
                                $scope.abilities.push("Weight");
                            }
     
                            this.addSpeed = function(){
                                $scope.abilities.push("Speed");
                            }
     
                            this.addLength = function(){
                                $scope.abilities.push("Length");
                            }
                        },
                        link : function(scope, element){
                            element.bind("mouseenter", function(){
                                console.log(scope.abilities);
                            })
                        }
                    }
                })
                .directive("weight", function(){
                    return {
                        restrict : "A",
                        require : "superman",
                        link : function(scope, element, attrs, superman){
                            superman.addWeight();
                        }
                    }
                })
                .directive("speed", function(){
                    return {
                        restrict : "A",
                        require : "superman",
                        link : function(scope, element, attrs, superman){
                            superman.addWeight();
                        }
                    }
                })
                .directive("length", function(){
                    return {
                        restrict : "A",
                        require : "superman",
                        link : function(scope, element, attrs, superman){
                            superman.addLength();
                        }
                    }
                })
     
    </script>

    controller : 指令的controller中放一些公共部分,通过require让多个指令共享controller中的数据。

    require : ^ 允许从父类开始查找 require:"^superman"; ? 如果找不到不抛出异常。

    scope : {} 创建独立作用域,没有原型继承。= or =attr “Isolate”作用域的属性与父作用域的属性进行双向绑定,任何一方的修改均影响到对方,这是最常用的方式;@ or @attr “Isolate”作用域的属性与父作用域的属性进行单向绑定,即“Isolate”作用域只能读取父作用域的值,并且该值永远的String类型; & or &attr “Isolate”作用域把父作用域的属性包装成一个函数,从而以函数的方式读写父作用域的属性,包装方法是$parse;

    link : 主要做一些dom操作;

    link和controller的相同点在于里面都可包含数据源和操作。不同点在于:link能控制渲染html元素的过程,而controller不能,controller的模版写死的,仅侧重于提供数据源和操作。

    使用link函数的Directive:

    (function(){
        var withoutController = function(){
            var tempalte = '<button id="addItem">Add Item</button><div></div>';
     
            var link = function(scope, element, attrs){
     
                //从scope中的datasource拿到数据源
                var items = angular.copy(scope.datasource),
                button = angular.element(document.getElementById('addItem'));
     
                button.on('click', addItem);
     
                render();
     
                function addItem(){
                    var name = 'new customer';
     
                    //执行Directive中传入的方法,带参数
                    scope.$apply(function(){
                        scope.add()(name);
                    });
     
                    items.push({
                        name: name
                    });
     
                    render();
                }
     
                function render(){
                    var html = '<ul>';
                    for(var i=0, len=item.length;i<len;i++){
                        html += '<li>' + items[i].name + '</li>'
                    }
                    html += '</ul>';
     
                    element.find('div').html(html);
                }
            };
     
            reutrn {
                restrict: 'EA',
                scope: {
                    datasource: '=',
                    add: '&'
                },
                link: link,
                template: template
            }
        };
     
        angular.module('directiveModule')
            .directive('withoutController', withoutController);
    }());

    使用controller的Directive:

    (function(){
        var withController = function(){
            var template = '<button ng-click="addItem()">Add Item</button><ul>' + '<li ng-repeat="item in items">{{::item.name}}</li></ul>',
     
            controller = ['$scope', function($scope){
                init();
     
                function init(){
                    $scope.items = angular.copy($scope.datasource);
                }
     
                $scope.addItem = function(){
                    var name = "customer new";
                    $scope.add()(name);
                    $scope.items.push({
                        name: name
                    });
                }
            }];
     
            return {
                restrict: 'EA',
                scope: {
                    datasource: '=',
                    add:'&'
                },
                controller: controller,
                template:template
            }
        };
     
        angular.module('directiveModule')
            .direcitve('withController', withController);
    }());
  • 相关阅读:
    Python3爬虫之爬取某一路径的所有html文件
    python获取数据网页数据并创建文件夹保存(基于python3.6)
    Python 爬取单个网页所需要加载的地址和CSS、JS文件地址
    java的关闭钩子(Shutdown Hook)
    如何形象的解释 webhook 这个词
    Webhook
    什么是webhook
    瞎折腾之Webhooks
    Java-马士兵设计模式学习笔记-观察者模式-读取properties文件,动态增加观察者
    怎么解决重装系统后“我的文档”拒绝访问(更改权限就可以了)
  • 原文地址:https://www.cnblogs.com/xuepei/p/5970477.html
Copyright © 2011-2022 走看看