EmberJS - 建立和刪除記錄

你可以在模型的例項上建立和刪除記錄。

語法

import Ember from 'ember';

export default Ember.Route.extend ({
   model() {
      //code here
   },
   actions:{
      addNewCategory(id, name) {
         this.controller.get('model').pushObject({ var1,va2});
      },
      deleteCategory(category) {
         this.controller.get('model').removeObject(model_name);
      }
   }
});

示例

下面給出的示例展示了記錄的建立和刪除。使用名稱 *record_demo* 建立新的路由，並在該路由中建立另一個路由，並將其命名為 *categories*。現在開啟 *router.js* 檔案，用於定義 URL 對映 -

import Ember from 'ember';                   
//Access to Ember.js library as variable Ember
import config from './config/environment';
//It provides access to app's configuration data as variable config 

//The const declares read only variable
const Router = Ember.Router.extend ({
   location: config.locationType,
   rootURL: config.rootURL
});

//Defines URL mappings that takes parameter as an object to create the routes
Router.map(function() {
   this.route('record_demo', function() {
      this.route('categories');
   });
});

//It specifies Router variable available to other parts of the app
export default Router;

使用以下程式碼開啟創建於 *app/templates/* 中的 *application.hbs* 檔案 -

{{#link-to 'record_demo'}}Go to Records demo page{{/link-to}}
{{outlet}}

當你單擊上面的連結時，它將開啟創建於 *app/templates/* 下的 *record_demo* 模板頁面。*record_demo.hbs* 檔案包含下列程式碼 -

<h2>Welcome...Click the below link for Categories page</h2>
{{#link-to 'record_demo.categories'}}Go to Categories page{{/link-to}}
{{outlet}}

上述模板頁面將開啟創建於 *app/templates/record_demo* 下的 *categories.hbs* 檔案，其中包含以下程式碼 -

<h2>Categories Page</h2>
<form>
   <label>ID:</label>
   {{input value=newCategoryId}}
   <label>NAME:</label>
   {{input value = newCategoryName}}
   //when user adds records, the 'addNewCategory' function fires and adds 
      the records to model
   <button type = "submit" {{action 'addNewCategory' newCategoryId newCategoryName}}>
      Add to list
   </button>
</form>

<ul>
   {{#each model as |category|}}
      <li>
         Id: {{category.id}}, Name: {{category.name}} 
         //when user delete records, the ‘deleteCategory’ function fires and remove 
            the records from model
         <button {{action 'deleteCategory' category}}>Delete</button>
      </li>
   {{/each}}
</ul>

//it counts the number of added records and removed records from the model
<strong>Category Counter: {{model.length}}</strong>
{{outlet}}

現在開啟創建於 app/routes/record_demo 中的 categories.js 檔案，其中包含以下程式碼 -

import Ember from 'ember';

export default Ember.Route.extend ({
   model() {
      //model will display these records when you execute the code 
      return [{
         id: 1,
         name: 'Category One'
      }, {
         id: 2,
         name: 'Category Two'
      }];
   },

   actions: {
      //it adds records to model
      addNewCategory(id, name) {
         this.controller.get('model').pushObject({id,name});
      },
      
      //it removes the records from model
      deleteCategory(category) {
         this.controller.get('model').removeObject(category);
      }
   }
});