如何在 Angular 10 中修补动态表单数组的值？

Question

我有一个动态 formArray，保存数据并且一切正常，但是我在修补值时遇到问题，而且我在网上找不到任何确切的解决方案。

下面是代码，

    <form [formGroup]="educationAndExperienceForm">
        <div formArrayName="educationForm">
            <div *ngFor="let education of educationAndExperienceForm.controls.educationForm['controls'];let i = index;"
                [formGroupName]="i">
                <h6 class="text-left circularBold" *ngIf="i == 0"><b>Highest Qualification</b></h6>
                <input type="text" class="education-inputs w-100 mt-3" placeholder="School/College/University"
                    formControlName="school"
                    [ngClass]="{ 'input-error': submitted && educationAndExperienceForm.controls.educationForm.controls[i].invalid }">
                <input type="text" class="education-inputs w-100 mt-3" placeholder="Degree Ex: Master's"
                    formControlName="degree"
                    [ngClass]="{ 'input-error': submitted && educationAndExperienceForm.controls.educationForm.controls[i].invalid }">
                <input type="text" class="education-inputs w-100 mt-3"
                    placeholder="Field of Education Ex: Computer Science" formControlName="specialization"
                    [ngClass]="{ 'input-error': submitted && educationAndExperienceForm.controls.educationForm.controls[i].invalid }">
                <div class="text-left">
                    <input type="text" class="education-inputs w-100 mt-3" placeholder="Graduate Year"
                        formControlName="passed_year"
                        [ngClass]="{ 'input-error': submitted && educationAndExperienceForm.controls.educationForm.controls[i].invalid }">
                </div>
                <div class="row text-right">
                    <div class="col-10"></div>
                    <div class="col-1">
                        <button type="button" class="btn deleteBtn" (click)="removeEducationFormGroup()">
                            <i class="fa fa-remove" style="font-size: 24px;" aria-hidden="true"></i>
                        </button>
                    </div>
                </div>
                <div class="text-left" *ngIf="!showAddAfterEducationHeading">
                    <button type="button" class="btn btn-light circularMedium mb-3 transparentBtn"
                        (click)="addEducationFormGroup()">
                        Add Education
                    </button>
                </div>
            </div>
            <div class="text-left" *ngIf="showAddAfterEducationHeading">
                <button type="button" class="btn btn-light circularMedium mb-3 transparentBtn"
                    (click)="addEducationFormGroup()">
                    Add Education
                </button>
            </div>
        </div>
</form>

TS文件

this.educationAndExperienceForm = this.fb.group({
      'educationForm': this.fb.array([this.createEducationFormGroup()])
});

private createEducationFormGroup(): FormGroup {
    return this.educationForm = this.fb.group({
      'school': ['', Validators.required],
      'degree': ['', Validators.required],
      'specialization': ['', Validators.required],
      'passed_year': ['', Validators.required]
    })
  }

下面是我尝试修补值的代码，

1. One way

fetchQualificationById(){
    this.apiService.fetchQualificationById(this.expertId).subscribe(res => {
      console.log("Response Ed = "+JSON.stringify(res));
      this.qualificationData = res['expertsQualification'];
     });
    let school = this.qualificationData['school'];
    let degree = this.qualificationData['degree'];
    let specialization = this.qualificationData['specialization'];
    let passed_year = this.qualificationData['passed_year'];
    this.educationAndExperienceForm.controls.educationForm.patchValue({
      'school': school,
      'degree': degree,
      'specialization': specialization,
      'passed_year': passed_year
    })
    // console.log("Get Qualification = "+JSON.stringify(this.educationAndExperienceForm.controls.educationForm.value))
  }

2. Second way

 

fetchQualificationById(){
    this.apiService.fetchQualificationById(this.expertId).subscribe(res => {
      console.log("Response Ed = "+JSON.stringify(res));
      this.qualificationData = res['expertsQualification'];
      for (let education=0; education < res['expertsQualification'].length; education++){
        const educationFormArray = this.educationAndExperienceForm.get("educationForm") as FormArray;
     }
     });
}

对于我使用的第一种方式，我无法使用 forEach .. 错误

已编辑

这里只有一个数组，但我们可以有一个空数组，这是为什么呢？ 下面是我的ts代码

@Component({
  selector: 'app-expert-education',
  templateUrl: './expert-education.component.html',
  styleUrls: ['./expert-education.component.css']
})
export class ExpertEducationComponent implements OnInit {

  educationForm: FormGroup;
  educationAndExperienceForm: FormGroup;
  experienceForm: FormGroup;
  submitted: boolean;
  showAddAfterEducationHeading: boolean;
  showAddAfterExperienceHeading: boolean;
  expertId;
  qualificationData: QualificationModel[] = [];
  experienceData: ExperienceModel[] = [];

  constructor(
    private route: Router,
    private fb: FormBuilder,
    private apiService: ApiService
  ) {
    this.submitted = false;
  }

  ngOnInit(): void {
    // this.educationForm = this.fb.group({
    //   'school': ['', Validators.required],
    //   'degree': ['', Validators.required],
    //   'field': ['', Validators.required],
    //   'graduatedYear': ['', Validators.required],
    //   'experience': ['', Validators.required],
    //   'designation': ['', Validators.required],
    //   'company': ['', Validators.required]
    // })
    this.expertId = sessionStorage.getItem('id_expert');
    this.educationAndExperienceForm = this.fb.group({
      'educationForm': this.fb.array([this.createEducationFormGroup()]),
      'experienceForm': this.fb.array([this.createExperienceFormGroup()])
    });
    this.showAddAfterEducationHeading = false;
    this.showAddAfterExperienceHeading = true;
    this.fetchQualificationById();
    this.fetchExperienceById();
  }

  addEducationFormGroup() {
    this.showAddAfterEducationHeading = true;
    const education = this.educationAndExperienceForm.get('educationForm') as FormArray;
    education.push(this.createEducationFormGroup());
  }

  addExperienceFormGroup() {
    this.showAddAfterExperienceHeading = true;
    const experience = this.educationAndExperienceForm.get('experienceForm') as FormArray;
    experience.push(this.createExperienceFormGroup());
  }

  removeEducationFormGroup(index) {
    const education = this.educationAndExperienceForm.get('educationForm') as FormArray
    if (education.length > 1) {
      education.removeAt(index);
    } else {
      education.reset();
    }
  }

  removeExperienceFormGroup(index) {
    const experience = this.educationAndExperienceForm.get('experienceForm') as FormArray
    if (experience.length > 1) {
      experience.removeAt(index);
    } else {
      experience.reset();
    }
  }

  private createEducationFormGroup(): FormGroup {
    return this.educationForm = this.fb.group({
      'school': ['', Validators.required],
      'degree': ['', Validators.required],
      'specialization': ['', Validators.required],
      'passed_year': ['', Validators.required]
    })
  }

  private createExperienceFormGroup(): FormGroup {
    return this.experienceForm = this.fb.group({
      'duration': ['', Validators.required],
      'designation': ['', Validators.required],
      'company_name': ['', Validators.required]
    })
  }

  onSubmit() {
    this.submitted = true;
    console.log("Form = " + JSON.stringify(this.educationAndExperienceForm.controls.educationForm.value) + "\nValid = " + this.educationAndExperienceForm.valid)
    if (this.educationAndExperienceForm.valid) {
      this.apiService.saveExpertEducationAndExperience(this.educationAndExperienceForm.controls.educationForm.value, this.educationAndExperienceForm.controls.experienceForm.value, this.expertId).subscribe(res => {
        console.log("Expert education & exp res = " + JSON.stringify(res));
        this.route.navigate(['/expert-welcome/expert-services']);
      })
    }
  }

  back() {
    this.route.navigate(['/expert-welcome/expert-profile']);
  }

  fetchQualificationById() {
    this.apiService.fetchQualificationById(this.expertId).subscribe(res => {
      this.qualificationData = res['expertsQualification'];
      const control = <FormArray>this.educationAndExperienceForm.controls['educationForm'];
      this.qualificationData.forEach(x => {
        control.push(this.fb.group({
          school: [x.school, Validators.required],
          degree: [x.degree, Validators.required],
          specialization: [x.specialization, Validators.required],
          passed_year: [x.passed_year, Validators.required]
        }));
      });
    });
  }

  fetchExperienceById() {
    this.apiService.fetchExperienceById(this.expertId).subscribe(res => {
      this.experienceData = res['expertExperience'];
      const control = <FormArray>this.educationAndExperienceForm.controls['experienceForm'];
      this.experienceData.forEach(x => {
        control.push(this.fb.group({
          duration: [x.duration, Validators.required],
          designation: [x.designation, Validators.required],
          company_name: [x.company_name, Validators.required],
        }));
      });
    });
  }

}

任何帮助表示赞赏。

Answer 1

问题似乎是 patchValue 无法填充表单数组。 您可以使用 push() 像常规数组一样填充表单数组。

假设您的 this.qualificationData 是一个包含许多“expertsQualification”（数组类型）的数组，并且类/接口 ExpertsQualification 具有属性“school”、“degree”、“specialization”和“passed_year”，您可以执行以下操作：

(this.educationAndExperienceForm.controls.educationForm as FormArray).reset(); //reset the FormArray

this.qualificationData.forEach(x => {
    (this.educationAndExperienceForm.controls.educationForm as FormArray)
    .push(this.fb.group({
        school: [x.school, Validators.required],
        degree: [x.degree, Validators.required],
        specialization: [x.specialization, Validators.required],
        passed_year: [x.passed_year, Validators.required]
    });
};

.. 以便您遍历数组，并为每个元素将表单组推送到表单数组。 请注意，将其转换为 FormArray 非常重要，例如

(this.educationAndExperienceForm.controls.educationForm as FormArray)

如果你不这样做，它将保持一个 AbstractControl 并且你将无法使用诸如 push、pull 等数组函数。