How am I supposed to append a Blob/File array to formData in typescript?

Question

This would work fine if I didn't have an ARRAY of files. But it needs to be an Array.

  let file1 = new File([""], "filename");
  let file2 = new File([""], "filename");
  let files = [file1, file2];
  let formData = new FormData();
  formData.append('files', files);

This works just fine in javascript. In typescript I get this error.

TS2345: Argument of type 'Blob[]' is not assignable to parameter of type 'string | Blob'. Type 'Blob[]' is not assignable to type 'string'.

Is there anything I can do besides // @ts-ignore?

Also the rest api I am working with requires the formData to be a Blob/File Array so I can't change anything there.

@KunalMukherjee No, this example only has one file but my problem is that FormData wants a Blob or String but not an Array of Blobs. — tanner burton, Jul 21 '20 at 17:16

score 2 · Accepted Answer · edited Jul 22 '20 at 16:36

2

You might have to do something like this:

let file1 = new File([""], "filename");
let file2 = new File([""], "filename");
let files = [file1, file2];
let formData = new FormData();
for (let file of files){
    formData.append('files', file);
}

Will you let me know if that works?

The reason i think that is based on the discussion here: How use formData.append for a array in typescript

edited Jul 22 '20 at 16:36

tanner burton

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answered Jul 21 '20 at 17:08

TKoL

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How am I supposed to append a Blob/File array to formData in typescript?

1 Answers1