AngularJs $http.post() does not send data

It's not angular's fault. Angular is designed to work in JSON world. So when $http service send AJAX request, it send all your data as a payload, not as form-data so that your backend application can handle it. But jQuery does some things internally. You instruct jQuery's $ajax module to bind form-data as JSON but before sending AJAX request, it serialized JSON and add application/x-www-form-urlencoded header. This way your backend application able to received form-data in form of post parameters and not JSON.

But you can modify angular $http service's default behavior by

1. Adding header
2. Serializing json

$httpParamSerializerJQLike is angular's in-built service which serializes json in the same way $.param does of jQuery.

$http({
    method: 'POST',
    url: 'request-url',
    data: $httpParamSerializerJQLike(json-form-data),
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8;'
    }
});

If you need a plugin to serialize form-data into JSON first, use this one https://github.com/marioizquierdo/jquery.serializeJSON

use this way. no need to write so much

 isAuth = $http.post("Yr URL", {username: username, password: password});

and in the nodejs back end

app.post("Yr URL",function(req,resp)
{

  var username = req.body.username||req.param('username');
  var password = req.body.password||req.param('password');
}

I hope this helps

I wrote a small PHP helper function that allows both types of input parameters :

function getArgs () {
    if ($input = file_get_contents('php://input') && $input_params = json_decode($input,true))
        return $input_params + $_POST + $_GET;
    return $_POST + $_GET;
}

Usage :

<?php
    include("util.php"); # above code
    $request = getArgs();

    $myVar = "";
    if (isset($request['myVar']))
        $myVar = $request['myVar'];
?>

Therefore no changes required to your JavaScript.

By using very simple method, we can follow this:

 $http({
        url : "submit_form_adv.php",
        method : 'POST',
        headers: {'Content-Type': 'application/x-www-form-urlencoded'},
        transformRequest: function(obj) {
            var str = [];
            for(var p in obj)
                str.push(encodeURIComponent(p)+' = '+encodeURIComponent(obj[p]));

            return str.join('&');
        },
        data : {sample_id : 100, sample_name: 'Abin John'},

    }).success(function(data, status, headers, config) {

    }).error(function(ata, status, headers, config) {

    });

Found the simple solution on

http://jasonwatmore.com/post/2014/04/18/post-a-simple-string-value-from-angularjs-to-net-web-api

return $http.post(Config.apiUrl + '/example/processfile', '"' + fileName + '"');

Just proposing a modernized version of @FelipeMiosso's answer:

.config(["$httpProvider", function ($httpProvider) {

  function buildKey(parentKey, subKey) {
    return parentKey + "[" + subKey + "]";
  }

  function buildObject(key, value) {
    var object = {};
    object[key] = value;
    return object;
  }

  function join(array) {
    return array.filter(function (entry) {
      return entry;
    }).join("&");
  }

  function arrayToQueryString(parentKey, array) {
    return join(array.map(function (value, subKey) {
      return toQueryString(buildObject(buildKey(parentKey, subKey), value));
    }));
  }

  function objectToQueryString(parentKey, object) {
    return join(Object.keys(object).map(function (subKey) {
      return toQueryString(buildObject(buildKey(parentKey, subKey), object[subKey]));
    }));
  }

  function toQueryString(input) {
    return join(Object.keys(input).map(function (key) {
      var value = input[key];
      if (value instanceof Array) {
        return arrayToQueryString(key, value);
      } else if (value instanceof Object) {
        return objectToQueryString(key, value);
      } else if (undefined !== value && null !== value) {
        return encodeURIComponent(key) + "=" + encodeURIComponent(value);
      } else {
        return "";
      }
    }));
  }

  function isQueryStringEligible(input) {
    return null !== input && "object" === typeof input && "[object File]" !== String(input);
  }

  var interceptor = [function () {
    return {
      request: function (config) {
        if (0 <= ["post", "put", "patch"].indexOf(config.method.toLowerCase()) && isQueryStringEligible(config.data)) {
          config.headers["Content-Type"] = "application/x-www-form-urlencoded;charset=utf-8";
          config.data = toQueryString(config.data);
        }
        return config;
      }
    };
  }];

  $httpProvider.interceptors.push(interceptor);

}])

ES6 version:

.config(["$httpProvider", function ($httpProvider) {

  "use strict";

  const buildKey = (parentKey, subKey) => `${parentKey}[${subKey}]`;

  const buildObject = (key, value) => ({ [key]: value });

  const join = (array) => array.filter((entry) => entry).join("&");

  const arrayToQueryString = (parentKey, array) =>
    join(array.map((value, subKey) =>
      toQueryString(buildObject(buildKey(parentKey, subKey), value))));

  const objectToQueryString = (parentKey, object) =>
    join(Object.keys(object).map((subKey) =>
      toQueryString(buildObject(buildKey(parentKey, subKey), object[subKey]))));

  const toQueryString = (input) => join(Object.keys(input).map((key) => {
    const value = input[key];
    if (value instanceof Array) {
      return arrayToQueryString(key, value);
    } else if (value instanceof Object) {
      return objectToQueryString(key, value);
    } else if (undefined !== value && null !== value) {
      return `${encodeURIComponent(key)}=${encodeURIComponent(value)}`;
    } else {
      return "";
    }
  }));

  const isQueryStringEligible = (input) =>
    null !== input && "object" === typeof input && "[object File]" !== String(input);

  const interceptor = [() => ({
    request(config) {
      if (0 <= ["post", "put", "patch"].indexOf(config.method.toLowerCase()) && isQueryStringEligible(config.data)) {
        config.headers["Content-Type"] = "application/x-www-form-urlencoded;charset=utf-8";
        config.data = toQueryString(config.data);
      }
      return config;
    }
  })];

  $httpProvider.interceptors.push(interceptor);

}])

I had this problem, the issue was i was not able to get the data while posting using above mentioned header i.e.

headers: {
    'Accept': 'application/json',
    'Content-Type': 'application/x-www-form-urlencoded'
}

While using jquery Ajax we were usually getting data in response.body at the backend server, but while implementing Angular ajax the data was not coming in response.body instead it was coming under

request.getParameterMap.keySet().iterator().next()