Angular，如何初始化和访问类实例的子对象数组

Question

我正在尝试从作为另一个父对象的子对象的对象数组传递对象，作为子组件的输入。

Data object 
export class CallauditHeaderClass {
   //more fields here..

    CallAuditDetails: CallauditDetailClass[];
}

Component Class:

constructor(){
   this.currentcallaudit = new CallauditHeaderClass();
}

ngOnInit() {

this.getCallAuditTypes();
 this.currentcallaudit.CallAuditDetails = [];
for (let callaudittype of this.callaudittypes) {

  let tmpcallauditdetail: CallauditDetailClass;
  tmpcallauditdetail = new CallauditDetailClass();       
  tmpcallauditdetail.CallAuditTypeId = callaudittype.CallAuditTypeId;
  tmpcallauditdetail.CallAuditTypeCode = callaudittype.CallAuditTypeCode;
  console.log(tmpcallauditdetail);
  this.currentcallaudit.CallAuditDetails.push(tmpcallauditdetail);
 }   

}

getCallAuditDetailForAuditType(CallAuditTypeCode: string)
 {
    return this.currentcallaudit.CallAuditDetails.find(calldetail => 
     calldetail.CallAuditTypeCode==CallAuditTypeCode);
  }  

 HTML:

 <app-callaudit-detail   
    [callauditdetail]= "getCallAuditDetailForAuditType 
     (callaudittype.CallAuditTypeCode)">
</app-callaudit-detail>  

我试图在UI上以JSON格式显示currentcallaudit对象，但该对象未初始化。请告知如何使其正常工作。