获取 Angular JS 中的 JSON 对象节点数答案

【问题标题】：Get the JSON Object Node Count in Angular JS获取 Angular JS 中的 JSON 对象节点数
【发布时间】：2017-08-13 05:01:04
【问题描述】：

我在获取参数名称具有特定值的 JSON 对象的计数时遇到问题

在下面的 JSON 中，我想获得名称为 2 的计数：IN PROGRESS。请您帮我告诉我这里出了什么问题。

name参数出现在issues>fields>status下

Plunker

JSON 数据

 {
  "expand": "schema,names",
  "startAt": 0,
  "maxResults": 50,
  "total": 257,
  "issues": [
    {
      "expand": "operations,versionedRepresentations,editmeta,changelog,renderedFields",
      "id": "1579217",
      "fields": {
        "created": "2017-08-11T13:03:52.000+0000",
        "resolutiondate": null,
        "status": {
          "name": "IN PROGRESS",
          "id": "3"
        }
      }
    },
    {
      "expand": "operations,versionedRepresentations,editmeta,changelog,renderedFields",
      "id": "1578077",
      "fields": {
        "created": "2017-08-10T13:14:53.000+0000",
        "resolutiondate": null,
        "status": {
          "name": "IN PROGRESS",
          "id": "10548"
        }
      }
    },
    {
      "expand": "operations,versionedRepresentations,editmeta,changelog,renderedFields",
      "id": "1562078",
      "fields": {
        "created": "2017-07-27T03:42:24.000+0000",
        "resolutiondate": null,
        "status": {
          "name": "To Do",
          "id": "10548"
        }
      }
    }
  ]
}

角度 JS

var app = angular.module('myApp', ['angular-loading-bar']);

app.controller("Controller", ["$scope", "$http", "$filter", "$window",
  function($scope, $http, $window, $filter) {

    $scope.findTheValue = function() {

      $http({
        method: 'POST',
        url: 'issues.json'
      }).then(function(response) {

        $scope.selectedCount = $filter('filter')(response.issues, {
          name: 'IN PROGRESS'
        }).length;

        console.log($scope.selectedCount);

      })
    }

  }
]);

【问题讨论】：

标签： angularjs json angularjs-filter

【解决方案1】：

你上面的代码有几个错误

首先，依赖注入的顺序不正确。

app.controller("Controller", ["$scope", "$http","$filter", "$window",
  function($scope, $http, $filter, $window) {

其次，由于您使用的是 POST，因此您必须将一些数据传递给 API 调用。将空数据{} 传递给您的POST 或使用GET

第三，您必须访问您的回复的数据属性，例如response.data.issues

var app = angular.module('myApp', []);
app.controller("Controller", ["$scope", "$http", "$filter", "$window",
    function($scope, $http, $filter, $window) {
        $scope.findTheValue = function() {
            $http({
                method: 'GET',
                url: 'issues.json'
            }).then(function(response) {
                $scope.selectedCount = $filter('filter')(response.data.issues, function(
                    inputs) {
                    if (inputs.fields.status.name == 'IN PROGRESS') return inputs;
                });
                console.log($scope.selectedCount.length);
            })
        }
    }
]);

打工者：https://plnkr.co/edit/ZOEN3X7Nt1onNeaHMp0H?p=preview

【讨论】：

【解决方案2】：

要获得count，您可以简单地通过数组iterate 并检查特定值出现了多少次。我使用reduce 来获取计数并在值为IN PROGRESS 时返回总和。

var data = {
  "expand": "schema,names",
  "startAt": 0,
  "maxResults": 50,
  "total": 257,
  "issues": [{
      "expand": "operations,versionedRepresentations,editmeta,changelog,renderedFields",
      "id": "1579217",
      "fields": {
        "created": "2017-08-11T13:03:52.000+0000",
        "resolutiondate": null,
        "status": {
          "name": "IN PROGRESS",
          "id": "3"
        }
      }
    },
    {
      "expand": "operations,versionedRepresentations,editmeta,changelog,renderedFields",
      "id": "1578077",
      "fields": {
        "created": "2017-08-10T13:14:53.000+0000",
        "resolutiondate": null,
        "status": {
          "name": "IN PROGRESS",
          "id": "10548"
        }
      }
    },
    {
      "expand": "operations,versionedRepresentations,editmeta,changelog,renderedFields",
      "id": "1562078",
      "fields": {
        "created": "2017-07-27T03:42:24.000+0000",
        "resolutiondate": null,
        "status": {
          "name": "To Do",
          "id": "10548"
        }
      }
    }
  ]
};

function getCount() {
  return data.issues.reduce((acc, curr) => {
    if(curr.fields.status.name === 'IN PROGRESS') {
      return acc + 1;
    }
    return acc;
  },0);
}

console.log(getCount());

【讨论】：