AngularJS最好Promise.all在Promise中只有return第一

Question

提前致谢。我是新手，坚持 AngularJs 诺言。原码为：

$scope.fillInRO = function (data){
  var defer = $q.defer();
  $scope.receive_order = data.receive_order;
  var orders = _.map(data.receive_order.purchase_orders,function (value) {
    return {purchase_order:value};
  });
  $scope.fillInPOInitial(orders).then(
    function (){
      defer.resolve();
    }
  )
  return defer.promise;
}

现在我需要添加另一个 Promise.all

let promises = ids.map((id,index) => {
        PurchaseOrderFactory.getPurchaseOrder(id,store_id).then(function(res){
        $scope.receive_order.receive_order_items[index].receive_order_item.display_unit = res.purchase_items[index].display_unit
      })
    })

通过console.log知道res是：

res = {
  purchase_items:[
    {display_unit: "kg"},
    {display_unit: "g"},
  ]
}

请求前，左值喜欢：

$scope.receive_order.receive_order_items = [
  {receive_order_item:{display_unit: null}},
  {receive_order_item:{display_unit: null}},
]

请求后，值喜欢：

$scope.receive_order.receive_order_items = [
  {receive_order_item:{display_unit: "kg"}},
  {receive_order_item:{display_unit: null}},
]

但我想要的是：

$scope.receive_order.receive_order_items = [
  {receive_order_item:{display_unit: "kg"}},
  {receive_order_item:{display_unit: "g"}},   // here the diff
]

我不知道如何在 promise 中正确嵌套 promise.all，我试过这样做：

  $q.all(promises).then(() =>{
    $scope.fillInPOInitial(orders).then(
      function (){
        defer.resolve()
      }
    )
  })

好像没什么区别，我还是得到第二个值为null:

$scope.receive_order.receive_order_items = [
  {receive_order_item:{display_unit: "kg"}},
  {receive_order_item:{display_unit: null}},
]

有什么想法吗？

Answer 1

promises 未在 promises 数组中返回，您在 promises 解析之前访问值，因此您没有获得正确的值。

let promises = ids.map((id,index) => {
         return PurchaseOrderFactory.getPurchaseOrder(id,store_id).then(function(res){
        $scope.receive_order.receive_order_items[index].receive_order_item.display_unit = res.purchase_items[index].display_unit
      })
    })

然后传给$q.all(promises )

Answer 2

感谢@mzulch，我发现 AngularJs Promise 没有任何问题。错误出在对 ids.map 的调用中再添加一个循环，问题解决：

  let promises = ids.map((id) => {
    PurchaseOrderFactory.getPurchaseOrder(id,store_id).then(function(res){
      res.purchase_items.map((purchase_item, index) => {
        data.receive_order.receive_order_items[index].receive_order_item.display_unit = purchase_item.display_unit
      })
    })
  })

AngularJS最好Promise.all在Promise中只有return第一

AngualrJS nest Promise.all in Promise only return the first

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promise

angularjs

angular-promise