Nested javascript promises

Question

I have an AJAX call that based on its result - I send another call.

uploadDocument = function (doc1, doc2) {
    $.ajax({
        type: "POST",
        url: "/API/UploadDocs/addDocument",
        data: doc1,
        contentType: "application/json"
    }).then(function (result) {
        console.log(result);
        doc2.id=result;
        return $.ajax({
            type: "POST",
            url: "/API/UploadDocs/addDocument",
            data: doc2,
            contentType: "application/json"
        }).then(function (result) {
        });
    });
}

But I'm getting an Illegal invocation error, what am I doing wrong?

Possible duplicate of [jQuery - Illegal invocation](https://stackoverflow.com/questions/10324594/jquery-illegal-invocation) — smarber, Aug 24 '17 at 16:14
@smarber It is not a duplicate, I saw this question but didn't find an answer there to my issue, thank you. — user3378165, Aug 24 '17 at 19:50

score 1 · Answer 1 · answered Aug 24 '17 at 19:55

1

Illegal Invocation error arises when there is some error in the data being passed through AJAX

Check the type of doc1 and doc2.. Also try passing processData:false to the ajax.

answered Aug 24 '17 at 19:55

rootkill

599
5
10

Thank you, when I called the `uploadDocument` function I sent an incorrect parameter, thanks! – user3378165 Aug 25 '17 at 05:50
Glad I could help – rootkill Aug 25 '17 at 14:34

Marco Talento · Accepted Answer · 2017-08-24T20:27:32.207

You are doing promise chaining wrongly! When you return a promise you have to continue with the then that called the promise you are resolving.

Read the chaining section: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/then

uploadDocument = function (doc1, doc2) {
    $.ajax({
        type: "POST",
        url: "/API/UploadDocs/addDocument",
        data: doc1,
        contentType: "application/json"
    }).then(function (result) {
        console.log(result);
        doc2.id=result;
        return $.ajax({
            type: "POST",
            url: "/API/UploadDocs/addDocument",
            data: doc2,
            contentType: "application/json"
        });
    }).then(function (result) {
      //Continue here
    });
}

Nested javascript promises

2 Answers2