Error encountered: Parsing error with Angular $HTTP response due to an unexpected token "E

Question

Error encountered: Parsing error with Angular $HTTP response due to an unexpected token "E

Here is an example of how to make a simple POST call using the Angular $HTTP service: authService.login = function(username, password){ var credentials = 'username=' + username + '&' + 'password=' + password;

        return $http({
            method: 'POST',
            url: href,
            headers: {'accept': acceptValue, 'content-type': contentType},
            data: credentials
        }).then(onSuccess, onError);
    };

I am encountering an issue where I can't retrieve the error status. Instead, I am getting a SyntaxError: Unexpected token E. The console initially shows the status 401 and then immediately displays the parse error. I'm curious about what is causing this issue behind the scenes, what it is attempting to parse, and why I am unable to access error.status.

javascript angularjs rest syntax error-handling

Answer 1

Answer №1

The issue may lie in the way you are handling your data serialization. Instead of manually constructing the string, consider passing the data directly into the data property as an object:

data: {username: username, password: password}

Angular is capable of automatically serializing the information within the data object.

If this approach does not work, Angular offers an alternative serializer that emulates the one found in jQuery. You can find documentation on this feature here. To make a request using this method, it would look something like the following:

            $http({
                url: "/auth/login",
                method: "POST",
                headers: {"Content-Type": "application/x-www-form-urlencoded"},
                data: $httpParamSerializerJQLike({
                    email: email,
                    password: password
                })
            })

If you opt for this solution, remember to inject $httpParamSerializerJQLike as a dependency.

Answer 2

The issue may lie in the way you are handling your data serialization. Instead of manually constructing the string, consider passing the data directly into the data property as an object:

data: {username: username, password: password}

Angular is capable of automatically serializing the information within the data object.

If this approach does not work, Angular offers an alternative serializer that emulates the one found in jQuery. You can find documentation on this feature here. To make a request using this method, it would look something like the following:

            $http({
                url: "/auth/login",
                method: "POST",
                headers: {"Content-Type": "application/x-www-form-urlencoded"},
                data: $httpParamSerializerJQLike({
                    email: email,
                    password: password
                })
            })

If you opt for this solution, remember to inject $httpParamSerializerJQLike as a dependency.

Answer 3

Answer №2

It appears that your request has been successfully sent and you have received a response.

I experimented with a RESTful service that returned a status code of 401. Below is the JavaScript code I used:

var href = 'https://contactsapi.apispark.net/v1/contacts/';
var acceptValue = 'application/json';
var contentType = 'application/json';
var credentials = {}; //'something';

function onSuccess(data, status, headers, config) {

}

function onError(data, status, headers, config) {
  console.log('data = '+JSON.stringify(response, null, 2));
}

$http({
    method: 'POST',
    url: href,
    headers: {'accept': acceptValue, 'content-type': contentType},
    data: credentials
    }).then(onSuccess, onError);

In my case, the response object contained the following information:

{
  "data": {
    "code": 401,
    "contactEmail": null,
    "description": "The request requires user authentication",
    "homeRef": "/",
    "reasonPhrase": "Unauthorized",
    "uri": "http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.2"
  },
  "status": 401,
  "config": {
    "method": "POST",
    "transformRequest": [
      null
    ],
    "transformResponse": [
      null
    ],
    "url": "http://localhost:8182/contacts/",
    "headers": {
      "accept": "application/json",
      "content-type": "application/json"
    },
    "data": {}
  },
  "statusText": "Unauthorized"
}

To troubleshoot, it may be helpful to examine the response content (headers / payload). Check if there is consistency between the actual content and the specified Content-Type header. For instance, receiving plain text content with a application/json content type could indicate a discrepancy.

I conducted a test to replicate such a scenario (XML content with an application/json content type) and encountered this error:

SyntaxError: Unexpected token <
  at Object.parse (native)
  at vc (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:15:480)
  at Zb (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:82:229)
  at https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:83:143
  at m (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:7:322)
  at dd (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:83:125)
  at d (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:84:380)
  at https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:119:113
  at n.$eval (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:133:221)
  at n.$digest (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:130:233)

Angular attempts to parse malformed JSON content, resulting in an error.

This issue seems similar to what you are experiencing. It suggests that the problem lies within the server rather than your Angular application.

Hoping this provides insight, Thierry

Answer 4

It appears that your request has been successfully sent and you have received a response.

I experimented with a RESTful service that returned a status code of 401. Below is the JavaScript code I used:

var href = 'https://contactsapi.apispark.net/v1/contacts/';
var acceptValue = 'application/json';
var contentType = 'application/json';
var credentials = {}; //'something';

function onSuccess(data, status, headers, config) {

}

function onError(data, status, headers, config) {
  console.log('data = '+JSON.stringify(response, null, 2));
}

$http({
    method: 'POST',
    url: href,
    headers: {'accept': acceptValue, 'content-type': contentType},
    data: credentials
    }).then(onSuccess, onError);

In my case, the response object contained the following information:

{
  "data": {
    "code": 401,
    "contactEmail": null,
    "description": "The request requires user authentication",
    "homeRef": "/",
    "reasonPhrase": "Unauthorized",
    "uri": "http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.2"
  },
  "status": 401,
  "config": {
    "method": "POST",
    "transformRequest": [
      null
    ],
    "transformResponse": [
      null
    ],
    "url": "http://localhost:8182/contacts/",
    "headers": {
      "accept": "application/json",
      "content-type": "application/json"
    },
    "data": {}
  },
  "statusText": "Unauthorized"
}

To troubleshoot, it may be helpful to examine the response content (headers / payload). Check if there is consistency between the actual content and the specified Content-Type header. For instance, receiving plain text content with a application/json content type could indicate a discrepancy.

I conducted a test to replicate such a scenario (XML content with an application/json content type) and encountered this error:

SyntaxError: Unexpected token <
  at Object.parse (native)
  at vc (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:15:480)
  at Zb (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:82:229)
  at https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:83:143
  at m (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:7:322)
  at dd (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:83:125)
  at d (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:84:380)
  at https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:119:113
  at n.$eval (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:133:221)
  at n.$digest (https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js:130:233)

Angular attempts to parse malformed JSON content, resulting in an error.

This issue seems similar to what you are experiencing. It suggests that the problem lies within the server rather than your Angular application.

Hoping this provides insight, Thierry

Error encountered: Parsing error with Angular $HTTP response due to an unexpected token "E

Answer №1

Answer №2

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