$http post multipart/form-data boundary not set - angularjs

Question

I am setting the boundary for the below post call but on chrome the boundary looks different from the one I set. how do I get my custom boundary "--test" to show up on the request payload?
var url = '/site/apkUpload';
var deferred = $q.defer();
console.log(formdata);
$http.post(url, formdata, {
processData: false,
headers: {'Content-Type': "multipart/form-data; charset=utf-8; boundary='--test'",
'Accept': "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
'x-access-token': token,
'cache-control': 'max-age=0'}
})
.success(function (response) {
deferred.resolve(response);
})
.error(function (reject) {
deferred.reject(reject);
});
return deferred.promise;
Request payload on chrome:
------WebKitFormBoundaryB5LjM2a6Qly3Xruj
Content-Disposition: form-data; name="packageName"
helo1
------WebKitFormBoundaryB5LjM2a6Qly3Xruj
Content-Disposition: form-data; name="name"
......
Thanks a lot!

Answer 1

I can interpret your question in 2 ways:
You are talking about why you are not getting ------WebKitFormBoundaryB5LjM2a6Qly3Xruj in the POST request header, which you are getting in the request payload. I had the same issue while sending a multi-part formdata using $http.post (also I was using FormData).The solution to this is using $http(config).To my understanding $http.post underlying uses $http() itself to generate XMLHttpRequest object, which should run the multipart/form-data encoding algorithm to set the multipart boundary in payload and the header as well. In $http.post, it seems whenever you give a custom config object it overwrites the header generated by the algorithm. This answer is also helpful.
If you just want to add a custom multipart boundary in the content-header, then you can achieve that by add a tranformRequest function in the config object:
var url = '/site/apkUpload';
var deferred = $q.defer();
console.log(formdata);
$http.post(url, formdata, {
processData: false,
transformRequest: function (data, headers) {
var boundary = yourCustomLogic();
headers()['Content-Type'] = 'multipart/form-data;charset=utf-
8;boundary=' + boundary;
},
'Accept': ...,
'x-access-token': token,
'cache-control': 'max-age=0'
})
.success( function () {...});