AngularJS：返回承诺的响应 - 即图像上传然后提交表单

I'm trying to understand promises and $q in AngularJS. I'd like to chain 2 functions, and execute them in order. The first is a file upload, and can take a while, so I need to wait for it to be executed before creating a DB record for it. I was originally using angular 1.3, hence the .success and .error methods. I'm trying to understand promises and $q in Ang