Ember.js 显示所属产品类别

我呈现了一个

产品

表，其中应包括每个产品的

类别

，但不包括

模板代码：

app/templates/products/index.hbs

[...]
<tbody>
  {{#each product in model}}
    <tr>
      <td>
        {{product.name}}
      </td>
      <td>
        {{product.category.name}}
      </td>
[...]

import DS from 'ember-data';

export default DS.RESTAdapter.extend({
  'namespace': 'api'
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  category: DS.belongsTo('category', { async: true })
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  products: DS.hasMany('product')
});

module.exports = function(app) {
  var express = require('express');
  var productsRouter = express.Router();

  productsRouter.get('/', function(req, res) {
    res.send({
      'products': [
          {"id":1,"name":"Orange","category":1},
          {"id":2,"name":"Banana","category":1},
          {"id":3,"name":"Potato","category":2}
        ]
      });
  });
  [...]

module.exports = function(app) {
  var express = require('express');
  var categoriesRouter = express.Router();

  categoriesRouter.get('/', function(req, res) {
    res.send({
      'categories': [
        {"id":1,"name":"Fruits","products:":[1,2]},
        {"id":2,"name":"Vegetables","products:":[3]}
        ]
      });
  });
  [...]

app/adapters/application.js

[...]
<tbody>
  {{#each product in model}}
    <tr>
      <td>
        {{product.name}}
      </td>
      <td>
        {{product.category.name}}
      </td>
[...]

import DS from 'ember-data';

export default DS.RESTAdapter.extend({
  'namespace': 'api'
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  category: DS.belongsTo('category', { async: true })
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  products: DS.hasMany('product')
});

module.exports = function(app) {
  var express = require('express');
  var productsRouter = express.Router();

  productsRouter.get('/', function(req, res) {
    res.send({
      'products': [
          {"id":1,"name":"Orange","category":1},
          {"id":2,"name":"Banana","category":1},
          {"id":3,"name":"Potato","category":2}
        ]
      });
  });
  [...]

module.exports = function(app) {
  var express = require('express');
  var categoriesRouter = express.Router();

  categoriesRouter.get('/', function(req, res) {
    res.send({
      'categories': [
        {"id":1,"name":"Fruits","products:":[1,2]},
        {"id":2,"name":"Vegetables","products:":[3]}
        ]
      });
  });
  [...]

app/models/product.js

[...]
<tbody>
  {{#each product in model}}
    <tr>
      <td>
        {{product.name}}
      </td>
      <td>
        {{product.category.name}}
      </td>
[...]

import DS from 'ember-data';

export default DS.RESTAdapter.extend({
  'namespace': 'api'
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  category: DS.belongsTo('category', { async: true })
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  products: DS.hasMany('product')
});

module.exports = function(app) {
  var express = require('express');
  var productsRouter = express.Router();

  productsRouter.get('/', function(req, res) {
    res.send({
      'products': [
          {"id":1,"name":"Orange","category":1},
          {"id":2,"name":"Banana","category":1},
          {"id":3,"name":"Potato","category":2}
        ]
      });
  });
  [...]

module.exports = function(app) {
  var express = require('express');
  var categoriesRouter = express.Router();

  categoriesRouter.get('/', function(req, res) {
    res.send({
      'categories': [
        {"id":1,"name":"Fruits","products:":[1,2]},
        {"id":2,"name":"Vegetables","products:":[3]}
        ]
      });
  });
  [...]

app/models/category.js

[...]
<tbody>
  {{#each product in model}}
    <tr>
      <td>
        {{product.name}}
      </td>
      <td>
        {{product.category.name}}
      </td>
[...]

import DS from 'ember-data';

export default DS.RESTAdapter.extend({
  'namespace': 'api'
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  category: DS.belongsTo('category', { async: true })
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  products: DS.hasMany('product')
});

module.exports = function(app) {
  var express = require('express');
  var productsRouter = express.Router();

  productsRouter.get('/', function(req, res) {
    res.send({
      'products': [
          {"id":1,"name":"Orange","category":1},
          {"id":2,"name":"Banana","category":1},
          {"id":3,"name":"Potato","category":2}
        ]
      });
  });
  [...]

module.exports = function(app) {
  var express = require('express');
  var categoriesRouter = express.Router();

  categoriesRouter.get('/', function(req, res) {
    res.send({
      'categories': [
        {"id":1,"name":"Fruits","products:":[1,2]},
        {"id":2,"name":"Vegetables","products:":[3]}
        ]
      });
  });
  [...]

server/mocks/products.js

[...]
<tbody>
  {{#each product in model}}
    <tr>
      <td>
        {{product.name}}
      </td>
      <td>
        {{product.category.name}}
      </td>
[...]

import DS from 'ember-data';

export default DS.RESTAdapter.extend({
  'namespace': 'api'
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  category: DS.belongsTo('category', { async: true })
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  products: DS.hasMany('product')
});

module.exports = function(app) {
  var express = require('express');
  var productsRouter = express.Router();

  productsRouter.get('/', function(req, res) {
    res.send({
      'products': [
          {"id":1,"name":"Orange","category":1},
          {"id":2,"name":"Banana","category":1},
          {"id":3,"name":"Potato","category":2}
        ]
      });
  });
  [...]

module.exports = function(app) {
  var express = require('express');
  var categoriesRouter = express.Router();

  categoriesRouter.get('/', function(req, res) {
    res.send({
      'categories': [
        {"id":1,"name":"Fruits","products:":[1,2]},
        {"id":2,"name":"Vegetables","products:":[3]}
        ]
      });
  });
  [...]

server/mocks/categories.js

[...]
<tbody>
  {{#each product in model}}
    <tr>
      <td>
        {{product.name}}
      </td>
      <td>
        {{product.category.name}}
      </td>
[...]

import DS from 'ember-data';

export default DS.RESTAdapter.extend({
  'namespace': 'api'
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  category: DS.belongsTo('category', { async: true })
});

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  products: DS.hasMany('product')
});

module.exports = function(app) {
  var express = require('express');
  var productsRouter = express.Router();

  productsRouter.get('/', function(req, res) {
    res.send({
      'products': [
          {"id":1,"name":"Orange","category":1},
          {"id":2,"name":"Banana","category":1},
          {"id":3,"name":"Potato","category":2}
        ]
      });
  });
  [...]

module.exports = function(app) {
  var express = require('express');
  var categoriesRouter = express.Router();

  categoriesRouter.get('/', function(req, res) {
    res.send({
      'categories': [
        {"id":1,"name":"Fruits","products:":[1,2]},
        {"id":2,"name":"Vegetables","products:":[3]}
        ]
      });
  });
  [...]

---

您应该将

belongsTo

定义为异步：

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  category: DS.belongsTo('category', { async: true })
});

这将对您访问的每个类别执行GET请求

或者你也可以把产品放在一边

看看这个，它表明它可以工作

如果查看模拟服务器，您将看到以下路径：

categoriesRouter.get('/:id', function(req, res) {
  res.send({
    'categories': {
      id: req.params.id
    }
  });
});

正如您所见，当您请求

category

1时，它将返回一个只有该id的对象

所以添加

{async:true}

会根据

类别

向

/category/1

发出请求（当然是类别1）。您必须确保返回正确的对象

例如：

var categoryList = [
  {"id":1,"name":"Fruits","products:":[1,2]},
  {"id":2,"name":"Vegetables","products:":[3]}
]

categoriesRouter.get('/:id', function(req, res) {
  res.send({
    'categories': categoryList.filter(function(c) { 
      return c.id == req.params.id; 
    })[0]
  });
});

---

我做了这个改变，但没用。我的代码中还有其他bug吗？我添加了一个jsbin，其中有一个延迟加载的

belongsTo

关系的工作示例。它确实有效。我需要更多的信息。控制台中有任何异常吗？我看不出你发布的代码有任何错误。我更新了代码并添加了显示数据的屏幕截图。类别的名称为“未定义”。我必须发送不同的JSON吗？是的，这是意料之中的。当获取类别的承诺解析时，

name

属性将被填充。