Функция обратного вызова загрузки файла AWS запускается после выхода из родительской функции?

Question

У меня нет четкого представления о том, как работает функция обратного вызова aws, хотя при ее реализации я сталкиваюсь с проблемой, что она загружает файл после выхода из родительской функции:

uploadfile(file) {
    const params = {
        Bucket: 'test',
        Key: 'test/' + this.id,
        Body: file,
        ContentDisposition: 'attachment;filename="' + file.name + '"',
        ContentType: file.type
    };

    const bucket = new S3({ 
        accessKeyId: '****',
        secretAccessKey: '******'
    }); 

    bucket.upload(params, function(err, data) {
        if (err) {
            console.log('There was an error uploading your file: ', err);
            return false;
        }

        console.log('Successfully uploaded file.', data);
        localStorage.setItem('fileUpload', 'true');
        return true;
    });
}

Answer 1

I have also uploaded images through aws cognito. Refer below code this will help you :


import * as aws from 'aws-sdk';

    /**
     * function to initialize AWS
     **/
    initializeAWS() {
        this.bucket = new aws.S3({params: {Bucket: 'bucketName'} });  
    }


    /**
     * function to upload image through cognito
     **/
   public uploadFileAWSCognito(file: any, referenceId : any, callBack: any){  

      //get cognito credentials 
      this.userService.getCognitoId().subscribe(
              res => {
                  this.cognitoCredentials = res.data;
                  this.amazonCognitoId = this.cognitoCredentials.IdentityId;  
                  this.amazonCognitoToken = this.cognitoCredentials.Token;

                  //upload image to cognito
                  return new Promise((resolve, reject) => {
                      aws.config.update({ 
                        region: 'us-east-1',
                        credentials: new aws.CognitoIdentityCredentials({
                           IdentityPoolId: 'pool_Id',
                           IdentityId : this.amazonCognitoId,  
                           Logins: {
                              'cognito-identity.amazonaws.com': this.amazonCognitoToken
                           }  

                        })
                      });

                      let keyString;
                      if(referenceId=='Panel') {
                          keyString = 'panel/'+referenceId +"_"+ new Date().getTime() +'.jpeg'
                      } else {
                          keyString = 'profile/user/'+referenceId +'.jpeg?' + new Date().getTime()
                      } 

                      this.s3 = new AWS.S3({ apiVersion: '2006-03-01', params: { Bucket: 'bucketName ' } });
                      this.s3.upload({
                          Key: keyString,
                          Body: file,
                          StorageClass: 'STANDARD',
                          ACL: 'public-read'
                      }, (err: any, data: any) => {
                          if (err) {
                              console.log('err', err);
                              //return;
                              reject({ errorMSG: 'errorm message' });
                          }

                          //return uploaded image data
                          callBack(data);
                      });

                  });
              },
              error => {
                  this.commonService.hideLoading();
                  console.log(error);
              });

    }
}