Response from http post request gets cut in the middle - http

Question

I'm trying to connect to a webservice that provides some customer data through a POST request but the response gets cut in the middle (or it might be that the trigger function doesn't await the response to complete).
This is done in a flutter environment and the initState() triggers the request.
I have a data service for the customer stuff, CustomerDataService which extends DataService that contain some common stuff such as sending the request and so on.
So in short initState() invoke CustomerDataService.getCustomers(request) which in turn invokes and await DataService.post(endpoint, request).
Http-package: import 'package:http/http.dart' as http;
initState() which is the starting point:
final CustomerDataService _dataService =
new CustomerDataServiceProvider().getCustomerDataService();
#override
void initState() {
_getCustomers();
super.initState();
}
void _getActors() async {
_dataService.getCustomers(
request: new GetCustomersRequest(
navigations: _dataService.suggestedNavigations
),
).then((response) {
_customersResponse = response;
/// Set the state
refresh();
});
}
And then we have the CustomerDataService:
class _CustomerDataService extends DataService implements CustomerDataService
#override
Future<GetCustomersResponse> getCustomers(
{#required GetCustomersRequest request}) async {
String endpoint = createEndpoint(<String>[
App.appContext.identityInstance.rootUrl,
_CUSTOMERS_CONTROLLER,
_GET_CUSTOMERS_ENDPOINT
]);
http.Response res = await post(endpoint: endpoint, request: request.toJson());
if (res.body == null) {
return null;
}
try {
/// This prints an invalid JSON that is cut in the middle
print(res.body);
/// This one naturally throws an exception since res.body isn't valid.
dynamic json = jsonDecode(res.body);
return new GetCustomersResponse.fromJson(json);
} catch (e) {
print("Exception caught when trying to get customers");
print(e);
}
return null;
}
The exception from jsonDecode is
Bad state: No element
And then we have the DataService:
Future<http.Response> post(
{#required String endpoint,
Map<String, String> header,
Map<String, dynamic> request}) async {
if (header == null) {
header = _getHeader();
} else {
header.putIfAbsent(_AUTHORIZATION_KEY, () => _headerAuthorizationValue());
}
http.Response res = await http.post(Uri.parse(endpoint), headers: header);
_validateReponse(res);
return res;
}
I'm clearly doing something wrong but I just can't see it...
The request in DataService.post doesn't add the body (request parameter) in this code and that is another ticket i will file after I've looked more into it, the workaround for now is to change the service to not expect a body.
I've verified that the service behaves as expected with postman.
I hope someone can see where my error(s) is.
Thanks!
Edit 1:
I changed the code a bit so that initState() doesn't use the DataServices created by me but used the http-package directly.
http.post('http://localhost:50140/api/customer/getcustomers').then((res) {
if(res == null) {
print('Response is empty');
}
print('Status code ${res.statusCode}');
print(res.body);
});
super.initState();
}
And the exact same thing happens so I don't think this is due to the dataservices at least.
Edit 2:
Before someone digs to deep into this I just want to say that it doesn't seem to be the response from the service, the http package or the dataservices.
This blog will be updated as soon as I find the cause of the Bad state: no element exception.

Answer 1

Okay, I don't know how to do this but it turns out the question title is incorrect.
It's the terminal that cuts the text when it's too big...
There were no errors in the dataservices or the http package but rather in the conversion from the response body to my strongly typed model, deep down the model tree.
An associative property to the Customer model have an enum, both server- and client side.
The service serialize the enum with the index, the library I use for mapping tries to get the enum by name (case sensitive).
The entity with the problem
#JsonSerializable()
class Item extends Object with _$ItemSerializerMixin
The auto-generated mapping
json['itemType'] == null
? null
: /// I could probably just remove the singleWhere and add [(int)json['itemType']] instead but that would cause some hassle when I run build_runner again.
ItemType.values
.singleWhere((x) => x.toString() == "ItemType.${json['itemType']}")
So, as soon as I did some changes server side (ignored the serialization of the enum and added another property which returned the enum string value instead, to lower case) it started working. I want to look into this further so that I can serialize the enum index instead of the string value and have it mapped that way instead but unfortunately I don't have the time to do it now.
The packages used for the auto-mapping is build_runner and json_serializable.
I'm glad I found a solution, and I'm sorry that the solution turned out to be completely unrelated to the actual post. I hope this can help someone at least.