Starting a new project with a angularjs client app and a flask app providing the api. I'm using mongodb as the database. I had to immediately rule out jsonp since I would need the ability to POST across different ports. So we have localhost:9000 for the angular app and localhost:9001 for the flask app.

I went through and made the changed needed for CORS in my API as well as my angular files. See source below. First issue I ran in to was that there is a bug that CORS allow header does not recognize localhost in Chrome. I updated my hosts file so I could use moneybooks.dev and this worked for my GET requests without using JSONP.

Now, to the issues I'm facing. When submitting a POST request, its stating `Origin http://moneybooks.dev:9000 is not allowed by Access-Control-Allow-Origin` What? GET can go through but POST is declined. I see the request come through to flask but it returns HTTP 400. I need help making POST requests work.

Another issue, which may be related, is that on my GET requests, sometimes the GET request doesn't fire at all. Like in `BudgetCtrl` the loadBudget function. On #/budgets/budgetID the name of the budget will sometimes not load at all. I check the flask log and don't see a request coming through. Then I click refresh, I see the request, the budget name appears on the page however in the flask log I see an error. `[Errno 10053] An established connection was aborted by the software in your host machine.` Its a connection error that only appears in the flask log when the GET request succeeds.

Are these issues related? Can anyone see what I'm doing wrong?

**app.js**

```
'use strict';

angular.module('MoneybooksApp', ['ui.bootstrap', 'ngResource'])
  .config(['$routeProvider', '$httpProvider', function ($routeProvider, $httpProvider) {
    $httpProvider.defaults.useXDomain = true;
    delete $httpProvider.defaults.headers.common['X-Requested-With'];
    $routeProvider
      .when('/', {
        templateUrl: 'views/main.html',
        controller: 'MainCtrl'
      })
      .otherwise({
        redirectTo: '/'
      });
  }]);

```

**budgets.js**

```
'use strict';

angular.module('MoneybooksApp')
  .config(['$routeProvider', function ($routeProvider) {
    $routeProvider
      .when('/budgets', {
        templateUrl: 'views/budgets-list.html',
        controller: 'BudgetListCtrl'
      })
      .when('/budgets/:budgetID', {
        templateUrl: 'views/budget.html',
        controller: 'BudgetCtrl'
      });
  }])
  .controller('BudgetListCtrl', function ($scope, $http, $resource) {
    $scope.budgets = [];

    var init = function () {
      $scope.loadBudgets();
    }

    $scope.loadBudgets = function() {
      $http.get('http://moneybooks.dev:9001/api/budgets')
        .success(function (data) {
          $scope.budgets = data;
        })
        .error(function (data) {
          console.error(data);
        });
    };

    init();
  })
  .controller('BudgetCtrl', function ($scope, $http, $routeParams, $resource) {
    $scope.budget = {};

    var init = function () {
      $scope.loadBudget();
    };

    $scope.loadBudget = function() {
      $http.get('http://moneybooks.dev:9001/api/budgets/'+$routeParams['budgetID'])
        .success(function (data) {
          $scope.budget = data;
        })
        .error(function (data) {
          console.error(data);
        });
    };

    init();
  })
  .controller('TransactionCtrl', function ($scope, $http, $routeParams, $resource) {
    $scope.transactions = [];
    $scope.editing = false;
    $scope.editingID;

    var init = function () {};

    $scope.syncUp = function () {
      $http.post('http://moneybooks.dev:9001/api/budgets/'+$routeParams['budgetID']+'/transactions', {transactions: $scope.transactions});
    };

    $scope.syncDown = function () {
      $http.get('http://moneybooks.dev:9001/api/budgets/'+$$routeParams['budgetID']+'/transactions')
        .success(function (transactions) {
          $scope.transactions = transactions;
        });
    };

    $scope.add = function() {
      $scope.transactions.push({
        amount: $scope.amount,
        description: $scope.description,
        datetime: $scope.datetime
      });

      reset();
      $scope.defaultSort();
    };

    $scope.edit = function(index) {
      var transaction = $scope.transactions[index];

      $scope.amount = transaction.amount;
      $scope.description = transaction.description;
      $scope.datetime = transaction.datetime;

      $scope.inserting = false;
      $scope.editing = true;
      $scope.editingID = index;
    };

    $scope.save = function() {
      $scope.transactions[$scope.editingID].amount = $scope.amount;
      $scope.transactions[$scope.editingID].description = $scope.description;
      $scope.transactions[$scope.editingID].datetime = $scope.datetime;

      reset();
      $scope.defaultSort();
    };

    var reset = function() {
      $scope.editing = false;
      $scope.editingID = undefined;

      $scope.amount = '';
      $scope.description = '';
      $scope.datetime = '';
    };

    $scope.cancel = function() {
      reset();
    };

    $scope.remove = function(index) {
      $scope.transactions.splice(index, 1);
      if ($scope.editing) {
        reset();
      }
    };

    $scope.defaultSort = function() {
      var sortFunction = function(a, b) {
        var a_date = new Date(a['datetime']);
        var b_date = new Date(b['datetime']);

        if (a['datetime'] === b['datetime']) {
          var x = a['amount'], y = b['amount'];
          return x > y ? -1 : x < y ? 1 : 0;
        } else {
          return a_date - b_date
        }
      };

      $scope.transactions.sort(sortFunction);
    };

    $scope.descriptionSuggestions = function() {
      var suggestions = [];

      return $.map($scope.transactions, function(transaction) {
        if ($.inArray(transaction.description, suggestions) === -1){
          suggestions.push(transaction.description);
          return transaction.description;
        }
      });
    };

    $scope.dateSuggestions = function () {
      var suggestions = [];

      return $.map($scope.transactions, function(transaction) {
        if ($.inArray(transaction.datetime, suggestions) === -1){
          suggestions.push(transaction.datetime);
          return transaction.datetime;
        }
      });
    }

    $scope.getRunningTotal = function(index) {
      var runningTotal = 0;
      var selectedTransactions = $scope.transactions.slice(0, index+1);
      angular.forEach(selectedTransactions, function(transaction, index){
        runningTotal += transaction.amount;
      });
      return runningTotal;
    };

    init();

    $(function(){
      (function($){
        var header = $('#budget-header');
        var budget = $('#budget');
        var pos = header.offset();

        $(window).scroll(function(){
          if ($(this).scrollTop() > pos.top && header.css('position') == 'static') {
            header.css({
              position: 'fixed',
              width: header.width(),
              top: 0
            }).addClass('pinned');
            budget.css({
              'margin-top': '+='+header.height()
            });
          } else if ($(this).scrollTop() < pos.top && header.css('position') == 'fixed') {
            header.css({
              position: 'static'
            }).removeClass('pinned');
            budget.css({
              'margin-top': '-='+header.height()
            });
          }
        });
      })(jQuery);
    });
  });

```

**API.py**

```
from flask import Flask, Response, Blueprint, request
from pymongo import MongoClient
from bson.json_util import dumps
from decorators import crossdomain
from bson.objectid import ObjectId

try:
    import json
except ImportError:
    import simplejson as json

class APIEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, objectid.ObjectID):
            return str(obj)

app = Flask(__name__)

client = MongoClient()
db = client['moneybooks']

api = Blueprint('api', __name__, url_prefix="/api")

@api.route('/budgets', methods=['GET', 'POST', 'OPTIONS'])
@crossdomain(origin='*', methods=['GET', 'POST', 'OPTIONS'], headers=['X-Requested-With', 'Content-Type', 'Origin'])
def budgets():
    if request.method == "POST":
        budget_id = db.budgets.insert({
            'name': request.form['name']
        })
        budget_json = dumps(db.budgets.find_one({'_id': budget_id}), cls=APIEncoder)

    if request.method == "GET":
        budget_json = dumps(db.budgets.find(), cls=APIEncoder)

    return Response(budget_json, mimetype='application/json')

@api.route('/budgets/<budget_id>', methods=['GET', 'OPTIONS'])
@crossdomain(origin='*', methods=['GET', 'OPTIONS'], headers=['X-Requested-With', 'Content-Type', 'Origin'])
def budget(budget_id):
  budget_json = dumps(db.budgets.find_one({'_id': ObjectId(budget_id)}), cls=APIEncoder)
  return Response(budget_json, mimetype='application/json')

@api.route('/budgets/<budget_id>/transactions', methods=['GET', 'POST', 'OPTIONS'])
@crossdomain(origin='*', methods=['GET', 'POST', 'OPTIONS'], headers=['X-Requested-With', 'Content-Type', 'Origin'])
def transactions(budget_id):
    if request.method == "POST":
        db.budgets.update({
            '_id': ObjectId(budget_id)
        }, {
            '$set': {
                'transactions': request.form['transactions']
            }
        });
        budget_json = dumps(db.budgets.find_one({'_id': ObjectId(budget_id)}), cls=APIEncoder)

    if request.method == "GET":
        budget_json = dumps(db.budgets.find_one({'_id': ObjectId(budget_id)}).transactions, cls=APIEncoder)

    return Response(budget_json, mimetype='application/json')

app.register_blueprint(api)

if __name__ == '__main__':
    app.config['debug'] = True
    app.config['PROPAGATE_EXCEPTIONS'] = True
    app.run()

```

**decorators.py**

```
from datetime import timedelta
from flask import make_response, request, current_app
from functools import update_wrapper

def crossdomain(origin=None, methods=None, headers=None, max_age=21600, attach_to_all=True, automatic_options=True):
    if methods is not None:
        methods = ', '.join(sorted(x.upper() for x in methods))
    if headers is not None and not isinstance(headers, basestring):
        headers = ', '.join(x.upper() for x in headers)
    if isinstance(max_age, timedelta):
        max_age = max_age.total_seconds()

    def get_methods():
        if methods is not None:
            return methods

        options_resp = current_app.make_default_options_response()
        return options_resp.headers['allow']

    def decorator(f):
        def wrapped_function(*args, **kwargs):
            if automatic_options and request.method == 'OPTIONS':
                resp = current_app.make_default_options_response()
            else:
                resp = make_response(f(*args, **kwargs))
            if not attach_to_all and request.method != 'OPTIONS':
                return resp

            h = resp.headers
            h['Access-Control-Allow-Origin'] = origin
            h['Access-Control-Allow-Methods'] = get_methods()
            h['Access-Control-Max-Age'] = str(max_age)

            if headers is not None:
                h['Access-Control-Allow-Headers'] = headers
            return resp

        f.provide_automatic_options = False
        f.required_methods = ['OPTIONS']
        return update_wrapper(wrapped_function, f)
    return decorator

```

**Edit**

Output from chrome dev console.

Console:

`XMLHttpRequest cannot load http://moneybooks.dev:9001/api/budgets/5223e780f58e4d20509b4b8b/transactions. Origin http://moneybooks.dev:9000 is not allowed by Access-Control-Allow-Origin.`

Network

```
Name: transactions /api/budgets/5223e780f58e4d20509b4b8b
Method: POST
Status: (canceled)
Type: Pending
Initiator: angular.js:9499
Size: 13 B / 0 B
Latency: 21 ms

```