如何在自己的 class 中调用 new object 中的构造函数 function

Question

When I try to call this.logger.error() inside new Promise it won't work.How can I call this.logger.error() inside the new Promise . As of my knowledge this refers to the outside class, how to call the logger inside Promise object.

export class MyClass {
    constructor(@Inject(WINSTON_MODULE_PROVIDER) private readonly logger: Logger) {}


    async uploadfile(buffer, key: string): Promise<string> {
            const params = {
                Body: buffer,
                Bucket: 's3Bucket',
                Key: key,
                ContentType: 'application/pdf',
                ACL: 'public-read',
            };
            const path: string = await new Promise((resolve, reject) => {
                s3.upload(params, function(err, data) {
                    if (err) {
                        this.logger.error('Error',err)
                        reject('Error occurred');
                    }
                    return resolve(data.Location);
                });
            });

            return path;

    }
}

Answer 1

The keyword this will only bind the scope which it is called. Calling it directly in a function that is not a class member/instance will bind to the function scope. You can assign this to a variable and use the variable inside your Promise

class Example {

instanceFunction(){
  const thisReference = this
  return new Promise((accept)=>{
  accept(thisReference)
})

}

Above is example of how you would do it