基于EmberJS中的路由模型的控制器中的计算属性 [英] Computed property in controller based on route's model in EmberJS

问题描述

我想在控制器中实现计算属性，该属性会在路由模型中的数据更改时更改.

路线:

 从'ember'导入Ember;导出默认的Ember.Route.extend({模型() {返回新的Ember.RSVP.hash({成分:this.store.findAll('ingredient')，食谱:this.store.peekAll('recipe')});}，setupController:function(controller，modelHash){controller.setProperties(modelHash);}}); 

控制器:

 从'ember'导入Ember;导出默认的Ember.Controller.extend({pageNumber:0，页面大小:16页数:function(){var pages = [];如果(this.model！= null){var content = this.model.recipes;而(content.length> 0){pages.push(content.splice(0，this.get("pageSize"))));}}返回页面；} .property('model.recipes.@ each'，'pageSize')，recipesOnPage:function(){返回this.get('pages')[this.get('pageNumber')];} .property('pages'，'pageNumber')}); 

此代码不会产生任何错误，但不起作用-页面"始终为空.而且，"pages"属性不会在模型更改时重新计算.我究竟做错了什么?以及如何达到预期的效果?

P.S.灰烬版本-1.13.

解决方案

由于您已经修改了 setupController 钩子，因此您的 controller 具有属性 ingredients 和 recipes ，但没有 model 属性.

因此您的计算属性应为:

 页面:function(){//避免在这里使用模型//使用this.get('recipes')代替this.model.recipes} .property('recipes.[]'，'pageSize') 

SetupController挂钩指南链接.

I want to implement computed property in controller that changes when data in route's model changed.

Route:

import Ember from 'ember';

export default Ember.Route.extend({
    model() {
        return new Ember.RSVP.hash({
            ingredients: this.store.findAll('ingredient'),
            recipes: this.store.peekAll('recipe')
        });
    },

    setupController: function(controller, modelHash) {
        controller.setProperties(modelHash);
    }
});

Controller:

import Ember from 'ember';

export default Ember.Controller.extend({
    pageNumber: 0,
    pageSize: 16,

    pages: function() {
        var pages = [];
        if (this.model != null) {
            var content = this.model.recipes;
            while (content.length > 0) {
                pages.push(content.splice(0, this.get("pageSize")));
            }
        }
        return pages;
    }.property('model.recipes.@each', 'pageSize'), 

    recipesOnPage: function() {
        return this.get('pages')[this.get('pageNumber')];
    }.property('pages', 'pageNumber')
});

This code produce no error, but doesn't work - "pages" always empty. And "pages" property doesn't recomputed on model changing. What am I doing wrong? And how to achieve desired result?

P.S. Ember version - 1.13.

解决方案

Since you have modified setupController hook, your controller has properties ingredients and recipes, but has no model property.

So your computed property should be:

pages: function() {
 // avoid using model here
 // use this.get('recipes') instead of this.model.recipes
}.property('recipes.[]', 'pageSize')

SetupController hook guides link.

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