angularjs component

Component

https://docs.angularjs.org/guide/component

component本质上就是directive。

This is a shorthand for registering a special type of directive, which represents a self-contained UI component in your application. Such components are always isolated (i.e. scope: {}) and are always restricted to elements (i.e. restrict: 'E').

Component definitions are very simple and do not require as much configuration as defining general directives. Component definitions usually consist only of a template and a controller backing it.

MVC的本质就是将controller和template关联起来，controller将数据显示到template中。component将这种关联做的更好。

When not to use Components:

1. for directives that need to perform actions in compile and pre-link functions, because they aren't available
2. when you need advanced directive definition options like priority, terminal, multi-element
3. when you want a directive that is triggered by an attribute or CSS class, rather than an element

component解决了什么问题：

1. app中的某个部分如何重用
2. app中各部分之间的scope不是隔离的
3. component可以自由的重复使用
4. index.html被简化了，细节的实现都分离出来了，提高了可维护性
5. component是隔离的，不受外界影响，同时也不会影响app中的其他部分
6. 可以独立的测试我们的component

Comparison between Directive definition and Component definition

component使用

1. 文件名建议：xxxComponent.component.js
2. component名字规则和directive一样，定义的时候使用驼峰样式(myAwesomeComponent)，模板中使用的时候使用-分割(my-awesome-component)
3. template中使用controller的实例$ctrl替代scope来访问数据，这个实例别名可以自定义 - 使用controllerAs属性
4. controller可以使用controller()注册的controller，也可以使用行内定义的方式

<html ng-app="phonecatApp">
<head>
  ...
  <script src="bower_components/angular/angular.js"></script>
  <script src="app.js"></script>
  <script src="phone-list.component.js"></script>
</head>
<body>

  <!-- Use a custom component to render a list of phones -->
  <phone-list></phone-list>

</body>
</html>

// Define the `phonecatApp` module
angular.module('phonecatApp', []);

// Register `phoneList` component, along with its associated controller and template
angular.
  module('phonecatApp').
  component('phoneList', {
    template:
        '<ul>' +
          '<li ng-repeat="phone in $ctrl.phones">' +
            '<span>{{phone.name}}</span>' +
            '<p>{{phone.snippet}}</p>' +
          '</li>' +
        '</ul>',
    controller: function PhoneListController() {
      this.phones = [
        {
          name: 'Nexus S',
          snippet: 'Fast just got faster with Nexus S.'
        }, {
          name: 'Motorola XOOM™ with Wi-Fi',
          snippet: 'The Next, Next Generation tablet.'
        }, {
          name: 'MOTOROLA XOOM™',
          snippet: 'The Next, Next Generation tablet.'
        }
      ];
    },
   controllerAs: 'ctrl'
  });

example

var myMod = angular.module(...);
myMod.component('myComp', {
  template: '<div>My name is {{$ctrl.name}}</div>',
  controller: function() {
    this.name = 'shahar';
  }
});

myMod.component('myComp', {
  template: '<div>My name is {{$ctrl.name}}</div>',
  bindings: {name: '@'}
});

myMod.component('myComp', {
  templateUrl: 'views/my-comp.html',
  controller: 'MyCtrl',
  controllerAs: 'ctrl',
  bindings: {name: '@'}
});

API

component(name, options) returns ng.$compileProvider

https://docs.angularjs.org/api/ng/service/$compile#directive-definition-object

bindings

这个就是类似于directive中的scope属性, 支持:

1. @ 字符值 - input
2. < 单向绑定 - input
3. & 回调传递 - 父组件的方法，用于向上的交互 - output
4. = 双向绑定 - 设计原则中不推荐使用

angular.module('docsIsolateScopeDirective', [])
.controller('Controller', ['$scope', function($scope) {
  $scope.naomi = { name: 'Naomi', address: '1600 Amphitheatre' };
  $scope.igor = { name: 'Igor', address: '123 Somewhere' };
}])
.directive('myCustomer', function() {
  return {
    restrict: 'E',
    scope: {
      customerInfo: '=info'
    },
    templateUrl: 'my-customer-iso.html'
  };
});

    .component('qqtrMenu',{
        templateUrl:'/secu/components/menu/menu.component.html',
        bindings: {
            menuitems: "<"
        },
        controller: 'menuCompCtrl',
    })

交互式组件实例

https://plnkr.co/edit/?p=preview

index.html

<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Example - example-component-tabs-pane-production</title>

  <script src="//code.angularjs.org/snapshot/angular.min.js"></script>
  <script src="script.js"></script>

</head>
<body ng-app="docsTabsExample">
  <my-tabs>
  <my-pane title="Hello">
    <h4>Hello</h4>
    <p>Lorem ipsum dolor sit amet</p>
  </my-pane>
  <my-pane title="World">
    <h4>World</h4>
    <em>Mauris elementum elementum enim at suscipit.</em>
    <p><a href ng-click="i = i + 1">counter: {{i || 0}}</a></p>
  </my-pane>
</my-tabs>
</body>
</html>

<!--
Copyright 2017 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
-->

script.js

(function(angular) {
  'use strict';
angular.module('docsTabsExample', [])
  .component('myTabs', {
    transclude: true,
    controller: function MyTabsController() {
      var panes = this.panes = [];
      this.select = function(pane) {
        angular.forEach(panes, function(pane) {
          pane.selected = false;
        });
        pane.selected = true;
      };
      this.addPane = function(pane) {
        if (panes.length === 0) {
          this.select(pane);
        }
        panes.push(pane);
      };
    },
    templateUrl: 'my-tabs.html'
  })
  .component('myPane', {
    transclude: true,
    require: {
      tabsCtrl: '^myTabs'
    },
    bindings: {
      title: '@'
    },
    controller: function() {
      this.$onInit = function() {
        this.tabsCtrl.addPane(this);
        console.log(this);
      };
    },
    templateUrl: 'my-pane.html'
  });
})(window.angular);

/*
Copyright 2017 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
*/

my-pane.html

<div class="tab-pane" ng-show="$ctrl.selected" ng-transclude></div>

<!--
Copyright 2017 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
-->

my-tabs.html

<div class="tabbable">
  <ul class="nav nav-tabs">
    <li ng-repeat="pane in $ctrl.panes" ng-class="{active:pane.selected}">
      <a href="" ng-click="$ctrl.select(pane)">{{pane.title}}</a>
    </li>
  </ul>
  <div class="tab-content" ng-transclude></div>
</div>

<!--
Copyright 2017 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
-->

基于组件的开发

https://docs.angularjs.org/guide/component

一个应用应该是一个组件数，每个组件只控制自己的视图和数据. bindings只用字符和单向绑定，数据单向流入; 使用&绑定父组件的方法，实现向上交互

推荐和参考：

https://docs.angularjs.org/tutorial/step_03

https://docs.angularjs.org/api/ng/provider/$compileProvider#component

In order to retrieve and instantiate a component's controller, AngularJS provides the $componentController service.