Why isn't my AngularJS post receiving data from the server? - angularjs

I am posting to the server using the following in AngularJS:
$http.post('/myurl', {my: "data"}, function(data, status, headers, config) {
console.log("returned");
});
In Chrome Developer Tools, the server is sending back a 200 OK status message. However, my callback is never triggered (i.e. nothing printing to the console). Why is AngularJS not printing the message even though the server returns OK?

I've not seen request written like that, generally you want to do something like:
$http.post('/myurl', {my: "data"})
.success(function(data) {
console.log("returned");
});
or
$http.post('/myurl', {my: "data"})
.then(function(data) {
console.log("returned");
});

you can try
return $http({url: '/myurl' , method: "POST",data:my});
you can also click on F12 chrome console to see the exact error
in order to serr the results data you can add
$http({url: '/myurl' , method: "POST",data:my}).then(
function(result){
console.log(result);
}

Related

How to handle server down requests (AngularJS)

I'm making a POST request to a TOMCAT server using AngularJS. Below is a snippet of that code.
$http(<myRequest>).then(function(response) {
$scope.info = response.data;
}, function(response) {
$scope.error = response.data
});
This works fine as long as the server is up and running. In case of any error on the response, it populates the $scope.error variable with the error message. However, if the server is down, when I click the link that makes this request nothing is shown on the page, I can only see the error on the console of the browser.
How do I show this error on the page? I want to somehow notify the user that the server is down.
Regarding the docs:
A response status code between 200 and 299 is considered a success status and will result in the success callback being called.
That said, if your error handler gets called you may check for the status property of the response object. Values in the 400 or 500 range indicate problems that will prevent the server from processing your request. If you are configuring the server yourself, you are able to make up your own error codes and interpret them client side.
$http(<myRequest>).then(function success (response) {
$scope.info = response.data;
}, function error (response) {
if (response.status === <server is down http status>) {
//do something here
$scope.error = "server is down msg";
}
else {
$scope.error = response.data;
}
});
I tried to post data to a non-existent server which gave me the status code -1. If your server is really down, you may have to check for this value.
Edit: There's also a statusText property within your response that could be helpful :)

Angular REST returning Syntax error on JSON parse

I am getting an error "syntax error JSON parse unexpected end of data at line 1 column 1 of json data". The RESTful service is runnning, a straight test returns valid json data (verified at http://jsonlint.com/)
[{"id":2,"name":"Flourescent Penetrant Inspection","description":"The fluorescent penetrant inspection process.","abbreviation":"FPI","tempId":null,"processType":"INSPECTION","indicationTypes":[{"id":1,"name":"Crack","description":"An identified crack on the piece.","abbreviation":"","tempId":null,"groupName":"","markupType":"LINE","useSizeDescription":true,"sizeDescription":"<= 1 in.::> 1 in.","rejectReason":"Crack","defaultDisposition":"MRB"},{"id":2,"name":"Inclusion","description":"An identified inclusion on the piece.","abbreviation":"","tempId":null,"groupName":"","markupType":"DOT","useSizeDescription":false,"sizeDescription":"","rejectReason":"Inclusion","defaultDisposition":"REWORK"}]},{"id":4,"name":"CMM","description":"The CMM process.","abbreviation":"CMM","tempId":null,"processType":"INSPECTION","indicationTypes":[]}]
The error in the HTTP response, yet it is returning a 200 message. The angular app is seeing it as an empty array. Any ideas?
The applicable part of the Controller is:
indicationTypeController.constant("indicationTypeUrl", "http://localhost:8080/services/api/indication-types.json");
indicationTypeController.controller('indicationTypeController', function ($scope, $http, $resource, indicationTypeUrl) {
$scope.indicationTypeResource = $resource(indicationTypeUrl+":id", { id: "#id" },
{ 'create': {method: "POST"}, 'update': {method: "PUT"}
});
$scope.listIndicationTypes = function () {
$http.get(indicationTypeUrl)
.success(function(data){
$scope.indicationTypes = data;
});
//$scope.indicationTypes = $scope.indicationTypeResource.query();
}
. . . .
As you can see I am currently using a $http.get, I also tried a query().
Any
Usually, the $http promise returns an object that contains the headers and the data. In your success handler for the $http, you have
$http.get(indicationTypeUrl)
.success(function(data){
$scope.indicationTypes = data;
});
I'm pretty sure that data is the full response and you need to get the specific data by using the data property of this object. Therefore, this would become the following:
$http.get(indicationTypeUrl)
.success(function(data){
$scope.indicationTypes = data.data;
});
In other implementations, instead of the passed in parameter being called data, it's usually called result, so that you can reference the contained data like result.data instead of data.data
The other thing to make sure of is that the Content-Type is set appropriately between the server and client. If it's not application\json you'll probably run into issues.
This is an CORS issue, please add the following to the response header, before sending the result.
"Access-Control-Allow-Origin" : "*"
For instance, if you are using play server (Java code) to serve the request, the following statement should be added to the method where you are returning the data from
response().setHeader("Access-Control-Allow-Origin", "*");

Restservice call returns 404

I am making a http.get call in angular js which returns a json file hosted locally.
Scenario:1 -- Success
$http.get("/SuccessResponse.json").success(function(jsonDataa) {
//some code
}).error(function (data, status, headers, config) {
alert("error::"+status);
return status;
});
The above code works perfectly fine and my code inside success gets executed alright.
Scenario : 2 -- Failure
However, when I host the same json on a URI, the http.get call returns 404 and alerts "error::404".
$http.get("http://`10.23.67.43:8080/Api/util`").success(function(jsonDataa) {
//some code
}).error(function (data, status, headers, config) {
alert("error::"+status);
return status;
});
Pls note when I hit the above url on my browser, it displays the JSON perfectly alright. It is only when I try to access it through rest call, it returns 404.
Scenario : 3 -- Success
Also, if I use a public URI (e.g. http://rest-service.guides.spring.io/greeting) it again works alright.
$http.get("http://rest-service.guides.spring.io/greeting").success(..
Can someone pls help in pointing out what's the issue over here?
It's a bit difficult to distinguish how it looks when you are mixing text and markup in your codetags.
However could it be so simple that you use ` in your url?

angularjs custom REST action and error handling

I'm having some trouble with error handling in a little angularjs application. I'm interacting with a Flask backend and a Postgres DB.
I have a factory service
appointServices.factory('Appointments', ['$resource', function($resource){
return $resource(someUrl, {}, {
query: { ... }
,
create: {
method: 'POST'
,url: 'http://somedomain:port/new/:name/:start/:end/:treatment'
,params: { start: '#start', end: '#end', name: '#name', treatment: '#treatment' }
,isArray:false
}
});
}
]);
Inside a controller I'm making the following call
Appointments.create($scope.appointment, function(value, responseHeaders) {
// success handler
console.debug('success: ', JSON.stringify(value));
}, function(httpResponse) {
// error handler
console.debug('error: ', JSON.stringify(httpResponse));
});
Here $scope.appointment contains the relevant parameters for the create action.
Now, in the backend I'm able to catch DB errors involving constraints and I'm trying to return an error code with a 'meaningful' message. So I have a python method
def create(name, start, end, treatment):
try:
...
transaction_status = 'ok'
code = 200
except IntegrityError as e:
...
transaction_status = 'IntegrityError'
code = 500
finally:
...
return make_response(transaction_status, code)
Everything works fine, I'm able to talk to the backend, create new data and insert this in the DB. As I said, any violation of the constraints is detected and the backend responds
curl -X POST "http://somedomain:port/new/foo/bar/baz/qux" -v
...
< HTTP/1.0 500 INTERNAL SERVER ERROR
...
IntegrityError
So, the problem is, no matter whether the action create was successful or not, the intended error handler specified inside the controller is always fired. Moreover, I always end up with a status code 404 in the httpResponse. Firebug shows correctly the code 500 as above, though.
Anybody has any idea of why I'm getting this behavior?
Any suggestions on how to improve the error handling mechanism are also welcome.
Thx in advance.
P.S. Following the documentation on $resource I have also tried variations on the factory service call, e.g.
Appointments.create({}, $scope.appointment, successCallback, errorCallback);
Appointments.create($scope.appointment, {}, successCallback, errorCallback);
with the same results.
Update:
Forgot to mention the important fact that I'm interacting with the backend via CORS requests. The POST request in create above is having place with the OPTIONS method instead. As I mentioned everything is working correctly except for the error response.
Under further investigation, I tried to isolate the factory service, in case I did something wrong, and I also tried the approach shown in the credit card example ($resource docs), but with no positive result.
However, I came up with two workarounds. Firstly, I was able to create a plain JQuery POST request, as in the example shown in the docs. This time, the request is not replaced by OPTIONS and I got the error code correctly.
I also managed to connect to the backend with the low-level $http service as follows:
var urlBase = 'http://somedomain:port/new/:name/:start/:end/:treatment';
var url = urlBase.replace(/:name/g, $scope.appointment.name);
url = url.replace(/:start/g, $scope.appointment.start);
url = url.replace(/:end/g, $scope.appointment.end);
url = url.replace(/:treatment/g, $scope.appointment.treatment);
// force method to be POST
var futureResponse = $http({ method: 'POST', url: url });
futureResponse.success(function (data, status, headers, config) {
console.debug('success: ', JSON.stringify(data));
});
futureResponse.error(function (data, status, headers, config) {
console.group('Error');
console.debug(JSON.stringify(status));
console.debug(JSON.stringify(data));
console.groupEnd();
});
This time, as in the case of JQuery, the request is done effectively with POST and error codes are correctly received.
Notice also that I'm not calling $http.post but I set the method to POST as part of the object parameter to $http, otherwise the connection takes places with OPTIONS as before.
Still trying to figure out what is happening with $resource.

angularjs $http.jsonp goes to .error instead of .success even when 200 is received

I'm building an AngularJS app which calls a NodeJS server that gets data from a DB.
The NodeJS returns a JSON.stringify(someArrayWithData).
Here is the AngularJS code:
$scope.getMainGroups = function(){
$http.jsonp("http://127.0.0.1:3000/get/MainGroups?callback=JSON_CALLBACK").success(function(data, status, headers, config) {
$scope.MainGroups = data;
}).error(function(data, status, headers, config) {
$scope.MainGroups = status;
});
};
$scope.MainGroups is going to the .error instead to the success even when I can see in the chrome debugger that the result came back (200 ok).
What am I missing?
You must return a valid JSON response on the server side. The 200 OK is just the GET request that is injected into the DOM. I bet you are not returning a valid JSON response from the server with right response code.
Here is an example on how to construct the response on the server side (PHP):
Simple jQuery, PHP and JSONP example?
As answered here you need to change the NodeJS response. The JSONP answer needs to start with the exact text that AngularJS added in the URL (for example 'angular.callbacks._1').
// changes in your server script used by NodeJS
// Required for JSONP calls, 'callback' matches the '?callback=JSON_CALLBACK'
app.set('jsonp callback name', 'callback');
// ... in your response change json to jsonp
res.jsonp(votes);
After doing these changes, when the server detects a 'callback' in the parameters, answers like this:
/**/ typeof angular.callbacks._1 === 'function' &&
angular.callbacks._1([{"votes":3,"title":"new topic", etc...
Now yes, AngularJS correctly calls back the 'success' function.

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