灰燼計算屬性上的hasMany關係不更新和雙打上保存

Question

我有兩種型號，一種用的hasMany關係其他：

裝運：

import DS from 'ember-data'; 

export default DS.Model.extend({ 
    pickup_address: DS.belongsTo('address', { inverse: null }), 
    delivery_address: DS.belongsTo('address', { inverse: null }), 
    shipment_lines: DS.hasMany('shipment-line', { inverse: null }), 
    shipmentPrice: Ember.computed('shipment_lines.@each.package_price', function() { 
    let price = 0; 
    this.get('shipment_lines').forEach(function(shipment_line) { 
     price += Number(shipment_line.get('package_price')); 
    }); 
    return price; 
    }), 
}); 

而且貨物線模型：

import DS from 'ember-data'; 

export default DS.Model.extend({ 
    description: DS.attr('string'), 
    package_weight: DS.attr('number'), 
    package_length: DS.attr('number'), 
    package_width: DS.attr('number'), 
    package_height: DS.attr('number'), 
    package_price: DS.attr('number'), 
}); 

在控制器中，當我向發貨添加新的裝運行時，我從API獲取包裝的價格並將其添加到裝運行：

addShipmentLine(shipmentLine) { 
    // Get price for shipment line 
    this.getShipmentLinePrice(shipmentLine); 

    // Add shipment line to shipment 
    let shipment = this.get('shipment'); 
    shipment.get('shipment_lines').addObject(shipmentLine); 
}, 

的getShipmentLinePrice功能（簡體）：

getShipmentLinePrice(shipmentLine) { 
    ... 
    // Get weight and type 
    let weight = shipmentLine.get('package_weight'); 
    let length = shipmentLine.get('package_length'); 
    let height = shipmentLine.get('package_height'); 
    let width = shipmentLine.get('package_width'); 

    // Fetch price from API 
    this.get('price').getPackagePrice(weight, length, height, width).then(
     (price) => { 
      shipmentLine.set('package_price', price['price']); 
     } 
    ); 
} 

最後，當我嘗試打印shipmentPrice模板，它不會更新。即使價格從服務器返回，並且設置了shipment_line s package_price。

此外，當我使用shipment.save();保存貨件並將路線重定向到展示頁面時，價格翻倍，直到我刷新頁面。刷新頁面後，所有內容都能正確顯示。

所以第一個問題是，如何在添加新的裝運行對象時獲得裝運計算屬性shipmentPrice以更新？還是不可能？

第二個問題是，爲什麼保存後價格翻了一番？

Answer 1

我終於想通這一個。那麼，至少我找到了解決辦法。保存模型後，我手動復位shipmentPrice到0：

freight_order.save().then(
    (new_freight_order) => { 
     shipment.set('shipmentPrice', 0); 
     this.transitionToRoute('shipments.show', new_freight_order.id); 
    } 
); 

我猜服務器respons得到了加入某種原因的計算值。

Answer 2

嘗試：

shipmentPrice: Ember.computed('shipment_lines.[]', function() { 
    let price = 0; 
    this.get('shipment_lines').forEach(function(shipment_line) { 
     price += Number(shipment_line.get('package_price')); 
    }); 
    return price; 
}),