New Typescript 1.8.4 build error: " Build: Property 'result' does not exist on type 'EventTarget'. "

Question

I am New to typescript. In my Durandal application I migrated to VS-2012 to VS-2015 means typescript 0.9 to typescript 1.8.4. After migrated I got so many build errors. I resolved all those except one. I am getting below build error on types of Events.

ERROR: " Build: Property 'result' does not exist on type 'EventTarget' "

And the code was exactly like this below:

var reader:any,
target:EventTarget;

reader= new FileReader();
reader.onload = function (imgsrc){
    var fileUrl = imgsrc.target.result;
}

"Imgsrc" is taking type event.

It's working fine with typescript 0.9 but with 1.8.4 it's throwing error as 'result' does not exist on type 'EventTarget'. Can any one help on this to resolve.

Note: "target:EventTarget" is getting from lib.d.ts

Answer 1

Instead of using event.target.result, you can just use FileReader.result.

For example,

const fileReader: FileReader = new FileReader();

fileReader.onload = (event: Event) => {
   event.target.result; // This is invalid
   fileReader.result; // This is valid
};