How to use formdata in JavaScript

Question

I want sending formdata including objects in objects

let submit_obj = { test : { kor : "korea" , eng : "usa"} }
let test_form = new FormData();
test_form.append(test, submit_obj );

    $.ajax({
        url : '/api/filesave',
        type : 'post',
        dataType : 'josn',
        data : test_form,
        contentType : false,
        processData : false,
        success: function(res){
            console.log('res',res);
        }                   
    });

and API response

req.body = Object { test : "[object Object]" }

How to extract the test value?? Thanks for your answer

Why are you using Form Data with an Object? Do you want to pass the object up to the server in one piece? jQuery handles it for you without FormData... — epascarello
– epascarello, Commented Oct 26, 2020 at 2:31
What data format does the backend code expect? How is it attempting to use the data from the request? — Phil
– Phil, Commented Oct 26, 2020 at 2:34
I would like to send this information along with the image file. — kudy
– kudy, Commented Oct 27, 2020 at 2:49

user3335966 · Accepted Answer · 2020-10-26 02:45:28Z

2

FormData.append() will convert value to string. In that case test : "[object Object]" is absolutly correct value;
So, You can try to use JSON.stringify:

test_form.append(test, JSON.stringify(submit_obj));

or Blob constructor:

test_form.append(test, new Blob([JSON.stringify(submit_obj)], {type:'application/json'}));

answered Oct 26, 2020 at 2:45

user3335966

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York Chen · Accepted Answer · 2020-10-26 02:35:29Z

-1

Please do not use dataType = JSON.

jQuery.ajax({
    url: '/api/filesave',
    data: test_form,
    cache: false,
    contentType: false,
    processData: false,
    type: 'POST',
    success: function(data){
        alert(data);
    }
});

answered Oct 26, 2020 at 2:35

York Chen

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