I'm trying to get some json data from a "remote" website. I run my web service on the 99000 port then, I launch my website on the 99001 port (http://localhost:99001/index.html).
I get the following message:
XMLHttpRequest cannot load http://localhost:99000/Services.svc/ReturnPersons. Origin http://localhost:99001 is not allowed by Access-Control-Allow-Origin.
Even If I launch my web page as an HTML file, I get this:
XMLHttpRequest cannot load http://localhost:99000/Services.svc/ReturnPersons.Origin null is not allowed by Access-Control-Allow-Origin.
The web service returns data. I try to catch the data items like this:
var url = "http://localhost:99000/Services.svc/ReturnPersons";
$.getJSON(url, function (data) {
success: readData(data)
});
function readData(data) {
alert(data[0].FirstName);
}
And I'm trying to get this structure:
[{"FirstName":"Foo","LastName":"Bar"},{"Hello":"Foo","LastName":"World"}]
Do you know why I'm getting this error?
This question is related to
jquery
json
cross-domain
cors
In new jQuery 1.5 you can use:
$.ajax({
type: "GET",
url: "http://localhost:99000/Services.svc/ReturnPersons",
dataType: "jsonp",
success: readData(data),
error: function (xhr, ajaxOptions, thrownError) {
alert(xhr.status);
alert(thrownError);
}
})
I am using WebAPI 3 and was facing the same issue. The issue has resolve as @Rytis added his solution. And I think in WebAPI 3, we don't need to define method RegisterWebApi
.
My change was only in web.config file and is working.
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Methods" value="GET, POST" />
</customHeaders>
</httpProtocol>
Thanks for you solution @Rytis!
Fiddle with 3 working solutions in action.
Given an external JSON:
myurl = 'http://wikidata.org/w/api.php?action=wbgetentities&sites=frwiki&titles=France&languages=zh-hans|zh-hant|fr&props=sitelinks|labels|aliases|descriptions&format=json'
Solution 1: $.ajax() + jsonp:
$.ajax({
dataType: "jsonp",
url: myurl ,
}).done(function ( data ) {
// do my stuff
});
Solution 2: $.ajax()+json+&calback=?:
$.ajax({
dataType: "json",
url: myurl + '&callback=?',
}).done(function ( data ) {
// do my stuff
});
Solution 3: $.getJSON()+calback=?:
$.getJSON( myurl + '&callback=?', function(data) {
// do my stuff
});
Documentations: http://api.jquery.com/jQuery.ajax/ , http://api.jquery.com/jQuery.getJSON/
Found a possible workaround that I don't believe was mentioned.
Here is a good description of the problem: http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api
Basically as long as you use forms/url-encoded/plain text content types you are fine.
$.ajax({
type: "POST",
headers: {
'Accept': 'application/json',
'Content-Type': 'text/plain'
},
dataType: "json",
url: "http://localhost/endpoint",
data: JSON.stringify({'DataToPost': 123}),
success: function (data) {
alert(JSON.stringify(data));
}
});
I use it with ASP.NET WebAPI2. So on the other end:
public static void RegisterWebApi(HttpConfiguration config)
{
config.MapHttpAttributeRoutes();
config.Formatters.Clear();
config.Formatters.Add(new JsonMediaTypeFormatter());
config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/plain"));
}
This way Json formatter gets used when parsing plain text content type.
And don't forget in Web.config:
<system.webServer>
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Methods" value="GET, POST" />
</customHeaders>
</httpProtocol>
Hope this helps.
Source: Stackoverflow.com