如何知道请求已经下载完成？

Question

Is there a way to know or a report about completed request or download? currently i only can get if a url can be request and in progress by return object json status response 200. but it not accurates to do action after that response. algorithm is client request a file to server. server response with json object with property size request file. then in client browser get response status and compare in local currently size download in local byte by byte with json object size property that return by server. if byte match than do something.

fetch('http://127.0.0.1/images/tileset.png')
  .then(function(myJson) {
    console.log(myJson);
  }); 

Answer 1

If you want to make sure that the two files -on internet and the local file- are the same, hashing will be better!

You should first return the response then console it.

 fetch('http://127.0.0.1/images/tileset.png') .then(function(myJson) { return myJson.blob(); }).then((myJson)=>console.log(myJson.size));