Question

使用Angular，并尝试将数据推送到某些数据为null的表单。在尝试映射数据模型时，我遇到了在传入数据属性为null时抛出异常的问题。

这是我的输入数据类：

export class Inputdata {
  sweepId: string;
  IndivId: string;
  FirstName: string;
  PrefName: string;
  LastName: string;
  Suffix: string;
  Language: string;
  Addr1: string;
  Addr2: string;
  Addr3: string;
  City: string;
  State: string;
  Zip: string;
  CountryCode: string;
  Country: string;
  PrimaryPhoneType: string;
  PrimaryPhone: string;
  PrimaryEmailType: string;
  PrimaryEmail: string;
  Positioncode: string;
  TrackingNumber: string;
  PositionTitle: string;
  AreaServed: string;
  DistrictServed: string;
  TrackingID: string;
}

数据从数据库移动到角度服务，并作为名为data的对象到达组件，该对象是Inputdata类型的数组。在订阅调用中，我将数据从Inputdata分配到Person数据类型，如下所示：

 this.people.getPersonById(this.Id).subscribe(data=>{
     this.inputs = data;
     console.log(this.inputs[0]);
     this.person.email.priEmailType = this.inputs[0].PrimaryEmailType || 'Not Provided';
     this.person.email.emailAddress = this.inputs[0].PrimaryEmail;
     this.person.phone.priPhoneType = this.inputs[0].PrimaryPhoneType;
     this.person.phone.Phone = this.inputs[0].PrimaryPhone;
     this.person.name.firstName = this.inputs[0].FirstName;
     this.person.name.prefName = this.inputs[0].PrefName;
     this.person.name.lastName = this.inputs[0].LastName;
     this.person.name.suffix = this.inputs[0].Suffix;
     this.person.address.addr1 = this.inputs[0].Addr1;
     this.person.address.addr2 = this.inputs[0].Addr2;
     this.person.address.addr3 = this.inputs[0].Addr3;
     this.person.address.city = this.inputs[0].City;
     this.person.address.state = this.inputs[0].State;
     this.person.address.zip = this.inputs[0].Zip;
     this.person.address.country = this.inputs[0].Country;
     this.person.address.countryCode = this.inputs[0].CountryCode;
     if(this.inputs.length >1){
       for(var i=0;i<this.inputs.length;i++){
        this.position.positionCode = this.inputs[i].Positioncode;
        this.position.positionTitle = this.inputs[i].PositionTitle;
        this.person.positions.push(this.position);
       }
     }
}

以下是来自数据库的数据样本。

[ { SweepID: 1,
    IndivId: 404873,
    FirstName: 'Paul',
    PrefName: null,
    LastName: 'Person',
    Suffix: null,
    Language: 'EN',
    Addr1: '13120 Skidaway Place',
    Addr2: null,
    Addr3: null,
    City: 'Tarry Town',
    State: 'LOUISIANA           ',
    Zip: '70737',
    CountryCode: 'US',
    Country: 'United States',
    PrimaryPhoneType: 'Home',
    PrimaryPhone: '(225)572-2268',
    PrimaryEmailType: null,
    PrimaryEmail: null,
    PositionCode: 'GM',
    TrackingNumber: '000131960',
    PositionTitle: 'General Manager',
    AreaServed: '027',
    DistrictServed: null,
    TrackingID: null },
  { SweepID: 82257,
    IndivId: 404873,
    FirstName: 'Paul',
    PrefName: null,
    LastName: 'Person',
    Suffix: null,
    Language: 'EN',
    Addr1: '13120 Skidaway Place',
    Addr2: null,
    Addr3: null,
    City: 'Tarry Town',
    State: 'LOUISIANA',
    Zip: '11111',
    CountryCode: 'US',
    Country: 'United States',
    PrimaryPhoneType: 'Home',
    PrimaryPhone: '(555)555-5555',
    PrimaryEmailType: null,
    PrimaryEmail: null,
    PositionCode: 'PRCONT',
    TrackingNumber: '000131960',
    PositionTitle: 'Primary Contact',
    AreaServed: null,
    DistrictServed: null,
    TrackingID: null } ]

我如何解决这个问题，接受Null值呢？

Answer 1

我出去了......

我怀疑你的实际问题可能是person，这就是你的错误。具有null值的响应不应该抛出这样的错误。

因此，当您没有正确初始化它时，它会尝试读取不存在的属性路径，例如：

person.email.priEmailType

其中person可能是一个空对象，但email是undefined，所以当它尝试阅读priEmailType时，它就不能因为email是undefined。

快速解决方法是将对象初始化为：

person = {email:{}, phone:{}, name:{}, address:{}}

例如，现在我们可以尝试阅读priEmailType，因为email不再是undefined

您可能想要制作一些辅助方法或其他内容，至少将值映射到person，特别是如果您想在其他地方使用它。

Answer 2

你在这里：

this.person.email.priEmailType = this.inputs[0].PrimaryEmailType || 'Not Provided';

也为其他领域做同样的事情：

this.person.name.lastName = this.inputs[0].LastName || '';

如果LastName为null / undefined，则默认为空字符串

具有null值的Angular.io属性抛出未定义的错误

2 个答案: