I'm working on an app using Visual Studio 2015 Cordova tools on Windows 8.1. Target is also Windows 8.1.
The app is caching HTTP GET request. So the second GET request to the same resource returns a cached response. I have tested after disabling the network adapter and I still get a response with the cached results.
I am using jsforce libray to connect to salesforce.com. I know I can add a timestamp on the url but I would like to find fix not a work around.
Any ideas?
[UPDATE]
Issue is not related to jsforce as it works well on Android. The error is specific to Windows 8.1 and cordova.
As suggested in the question, timestamping the url helps: I used:
var url = "https://api.myurl.com/" + param1 + "?" + new Date().getTime()
I wrote a simple library to add caching to REST requests for Cordova: https://github.com/glauber-md/mobile-simple-web-call#using-this-library .
The library will use a local database (sqlite) to fetch server data and cache it locally where applicable (e.g. HTTP GET requests with cache-related headers).
Once it receives a 304 Response, it will use the cached data.
To send a GET request, you'd use:
wscall.get(
'http://myserver.org/users/1234',
// (Optional) query strings
null,
function(responseData) {
// Do something when the response is successful
},
function(error) {
// Do something when an error happens
}
);
Then the data would come from remote server or local cache depending of the HTTP server response.
Maybe it will help you.
Related
I'm trying to read metadata from shoutcast stream using ASP.net WebAPI, .net core 2.1. All I need is the headers and not the audio data.
I found out that Shoutcast servers 2+ give stats xml page, but for compatibility reasons, I need to work this out so I can support v1 too. The /7.html does not give the title and genre.
Following is piece of relevant code:
HttpWebRequest request = null;
HttpWebResponse response = null;
request = (HttpWebRequest)WebRequest.Create(server);
request.Headers.Clear();
request.Headers.Add("GET", "/ HTTP/1.0");
// needed to receive metadata information
request.Headers.Add("Icy-MetaData", "1");
request.UserAgent = "WinampMPEG/5.09";
response = (HttpWebResponse)request.GetResponse();
info.Title=response.Headers["icy-name"];
info.Genre=response.Headers["icy-genre"];
When I run this code on IIS Express, or publish and run on IIS, I get this error:
An unhandled exception occurred while processing the request.
HttpRequestException: The server returned an invalid or unrecognized response.
System.Net.Http.HttpConnection.ThrowInvalidHttpResponse()
WebException: The server returned an invalid or unrecognized response.
System.Net.HttpWebRequest.GetResponse()
I have tried WebClient and StreamReader as well but the issue seems to be consistent.
However I tried the same code in Console Application and it seems to work just fine.
How can I get this to work through a WebAPI on IIS?
I had same issue. I used HttpClient and PostAsync to fix the issue.
It is to note that I initially tried my code with dot net framework rather than dot net core and it was working fine, so I think HttpWebResponse is not compatible with dot net core in some cases.
Have a look on below links, if using HttpClient still does not fix your issue. I hope it helps.
https://github.com/dotnet/corefx/issues/14897
https://github.com/dotnet/corefx/issues/30040
So I have been getting the infamous 404.3 error when trying to use AXAJ to access a .json file launching the site (or more of a test app hehe) through WebMatrix on localhost.
Yes, I am aware of the IIS configuration. I am on Windows 8.1(x64), so I had to even turn on MIME types functionality separately. I configured a MIME type for .json with application/javascript. Then I went and added a handler to *.json, pointed it to C:\WINDOWS\system32\inetsrv\asp.dll. I set the verbs to GET and POST (those are what I use in my ajax function). I also tried unchecking the "Invoke the handler only if request is mapped to..." to no avail.
I am using one function to send data to PHP file which writes it to the JSON file and then another to fetch data from the JSON file directly. Writing through PHP works. Fetching doesn't. I am completely at a loss, does anyone have any ideas? The code I am using to fetch the data is your bog-standard ajax:
function getDate(path, callback) {
var httpRequest = new XMLHttpRequest();
httpRequest.onreadystatechange = function() {
if (httpRequest.readyState === 4) {
if (httpRequest.status === 200) {
var data = JSON.parse(httpRequest.responseText);
if (callback) callback(data);
}
}
};
httpRequest.open('GET', path);
httpRequest.send();
}
When I host this on my server space, it works totally fine. But I want to get it to work locally for testing purposes as well.
If writing to the file works but fetching doesn't work. Then you should check for the link of the file.
The error 404 as the name refers to, is an error for the file name. There isn't any other sort of error, even the Ajax request is working fine and giving the error 404 (file not found). So the only thing that you can do is, to make sure that while fetching the data, you use the correct link.
Here can be a help, when you send the Request through Ajax, there is a Network tab in your Browser's console. Open it, and look for the request. It would in red color denoting an error and click it. You'll see that the link you're providing isn't valid.
Look for the errors in the File Link then and update it.
The lengths I go to, to clean up my profile...
When you require a JSON format, or any file for that matter you have to specify in your request what data type you need, IIS will not make any assumptions. So
xhr.setRequestProperty('Content-Type', 'application/json');
is something one must not forget. I set also the X-Requested-With header. Note that to reproduce this issue I used IIS that is installed on Windows 10 Pro, so not exactly the same system (3 years later - holy crap!).
The main problem about Access-Control-Allow-Origin I think. But when I configure the Web API project as defined in the given documentation, it still not working in chrome and firefox but working in IE well (it is about IE thinks localhost is not cross domain, AFAIK). I tried different ways to make it work but no result.
I put the example project to github repository. Project is very simple. There are two applications working on cross domains. It is very simple chat application like in signalr examples.
You must change the value of api host in client javascript file:
https://github.com/yusufuzun/WebApiSignalR/blob/master/ChatApp/Scripts/app/chat.js#L2
When you open the Chat page in mvc project, there will be two requests to api application
1- Regular ajax request (which is working fine)
2- Signalr negotiate request (cancelled)
And also I don't think browser disables the CORS because of if it disables there would not be an hit to server. So I think it is about browser but not about browser disables (something else).
Details are in repository
Readme: https://github.com/yusufuzun/WebApiSignalR/blob/master/README.md
Fiddler Results: https://github.com/yusufuzun/WebApiSignalR/blob/master/FiddlerResults
The bad part about it also is server returning 500 with this error:
System.InvalidOperationException: 'chat' Hub could not be resolved.
Which hub name is chat also.
https://github.com/yusufuzun/WebApiSignalR/blob/master/ChatApi/Hubs/ChatHub.cs#L10
You can enable CORS for Web Api in project with different ways for test purposes. Each one is giving different errors all about XMLHttpRequest Access-Control-Allow-Origin.
I commented them, so you can uncomment and make test for each one:
https://github.com/yusufuzun/WebApiSignalR/blob/master/ChatApi/Global.asax.cs#L24
https://github.com/yusufuzun/WebApiSignalR/blob/master/ChatApi/App_Start/WebApiConfig.cs#L14
https://github.com/yusufuzun/WebApiSignalR/blob/master/ChatApi/App_Start/WebApiConfig.cs#L16
https://github.com/yusufuzun/WebApiSignalR/blob/master/ChatApi/Controllers/ChatController.cs#L17
So what is going on here?
After I talked with David Fowler in JabbR, he mentioned the thing about using CORS with SignalR. My signalr startup code was wrong. So after changing the startup code like in his advice it worked well.
He also mentioned SignalR and Web API are working with different CORS definitions. So enabling or disabling one doesn't affect other.
Here is the new startup code:
app.Map("/signalr", map =>
{
map.UseCors(CorsOptions.AllowAll);
map.RunSignalR(new HubConfiguration()
{
EnableDetailedErrors = true,
EnableJavaScriptProxies = true
});
});
The old one:
app.MapSignalR(new HubConfiguration()
{
EnableDetailedErrors = true,
EnableJavaScriptProxies = true
}).UseCors(CorsOptions.AllowAll);
Hope it helps to somebody out there.
I'm having issues with using $http on ie8. The request does not reach the server, until I hit a refresh. Coming back to the same link still has the same problem until I hit refresh again.
The weird thing is if the web server is on LAN and the request is made to a server in LAN, it works fine. But if the webserver is hosted remotely, it does not work!
Here is the code:
Index.html
{{test}}
Controller
app.controller(
"TestController",
function( $scope, $http) {
var url = '/test/get_data';
$http.get(url).success(function(data) {
$scope.test = data;
});
}
);
I got this error: TypeError: Object doesn't support this property or methodundefined
I prepared a JSFiddle earlier but JSFiddle is broken in ie8 so I don't provide it here.
Unfortunately I don't have a remote server that I can share with you.
Edit
Previously I used an external url which gave me 'Access Denied' error in ie because of Same Origin Policy as mentioned by one answer below. But this was not my original problem. I still have the issue above when request is from the same origin
This is a cross domain request, which is not allowed in ajax because of Same Origin Policy.
There are two solutions for this
1. JSONP: It is a cross browser way to handle cross domain ajax requests using javascript callback mechanism
2. CORS: It is a HTML5 standard, it is implemented by most of the modern browsers except IE
Mongodb lab is not supporting jsonp since it has support for CORS, that is why your request is failing in IE and works in Chrome and other browsers.
As per this post they do not have any plan to support jsonp, so I don't thick there is a way to make this work in IE.
So I found the fix... Hope this helps anyone out there that experience this problem
Angular script needs to be loaded after jQuery. I didn't have this because Yii framework that I use autoloads jQuery and the angular was not included after the jQuery.
All the controller functions need to be at the end of body section (just before the closing )
Updating to angular 1.0.5 seems to fix the problem. The problem occurred in 1.0.4 with all the above tricks. I think is related to fix 791804bd
I am getting this Error
NETWORK_ERROR: XMLHttpRequest Exception 101
when trying to get XML content from one site.
Here is my code:
var xmlhttp;
if(window.XMLHttpRequest) {
xmlhttp = new XMLHttpRequest();
}
if (xmlhttp==null) {
alert ("Your browser does not support XMLHTTP!");
return;
}
xmlhttp.onReadyStateChange=function() {
if(xmlhttp.readyState==4) {
var value =xmlhttp.responseXML;
alert(value);
}
}
xmlhttp.open("GET",url,false);
xmlhttp.send();
//alert(xmlhttp.responseXML);
}
xmlhttp.open("GET",url,false);
xmlhttp.send(null);
Does any one have a solution?
If the url you provide is located externally to your server, and the server has not allowed you to send requests, you have permission problems. You cannot access data from another server with a XMLHttpRequest, without the server explicitly allowing you to do so.
Update: Realizing this is now visible as an answer on Google, I tried to find some documentation on this error. That was surprisingly hard.
This article though, has some background info and steps to resolve. Specifically, it mentions this error here:
As long as the server is configured to allow requests from your web application's origin, XMLHttpRequest will work. Otherwise, an INVALID_ACCESS_ERR exception is thrown
An interpretation of INVALID_ACCESS_ERR seems to be what we're looking at here.
To solve this, the server that receives the request, must be configured to allow the origin. This is described in more details at Mozilla.
The restriction that you cannot access data from another server with a XMLHttpRequest can apply even if the url just implies a remote server.
So:
url = "http://www.myserver.com/webpage.html"
may fail,
but:
url = "/webpage.html"
succeed - even if the request is being made from www.myserver.com
Request aborted because it was cached or previously requested? It seems the XMLHttpRequest Exception 101 error can be thrown for several reasons. I've found that it occurs when I send an XMLHttpRequest with the same URL more than one time. (Changing the URL by appending a cache defeating nonsense string to the end of the URL allows the request to be repeated. -- I wasn't intending to repeat the request, but events in the program caused it to happen and resulted in this exception).
Not returning the correct responseText or responseXML in the event of a repeated request is a bug (probably webKit).
When this exception occurred, I did get an onload event with readyState==4 and the request object state=0 and responseText=="" and responseXML==null. This was a cross domain request, which the server permits.
This was on an Android 2.3.5 system which uses webKit/533.1
Anyone have documentation on what the exception is supposed to mean?
Something like this happened with me when I returned incorrect XML (I put an attribute in the root node). In case this helps anyone.
xmlhttp.open("GET",url, true);
set the async part to true
I found a very nice article with 2 diferent solutions.
The first one implementing jQuery and JSONP, explaining how simple it is.
The second approach, it's redirecting trough a PHP call. Very simple and very nice.
http://mayten.com.ar/blog/42-ajax-cross-domain
Another modern method of solving this problem is Cross Origin Ressource Sharing.
HTML5 offers this feature. You can "wrap" your XMLhttp request in this CORS_request and
if the target browser supports this feature, you can use it and wont have no problems.
EDIT:
Additionaly i have to add that there are many reasons which can cause this Issue.
Not only a Cross Domain Restriction but also simply wrong Settings in your WEB.CONFIG of your Webservice.
Example IIS(.NET):
To enable HTTP access from external sources ( in my case a compiled Phonegap app with CORS request ) you have to add this to your WEB.CONFIG
<webServices>
<protocols>
<add name="HttpGet"/>
<add name="HttpPost"/>
</protocols>
</webServices>
Another scenario:
I got two webservices running... One on Port 80 and one on Port 90. This also gave me an XML HTTP Request Error. I even dont know why :). Nevertheless i think this can help many not well experienced readers.