Jan 20, 2021 05:19 PM|jainpratham27@gmail.com|LINK
Hi All,
I have a standard C# WebAPI project whose operations are getting called from Angular client application. This C# WebAPI application has CORS enabled on it. I am receiving the below error on entering the client application URL in browser:
Access to XMLHttpRequest at 'https://applicationservice.abc.com/api/AppToken/AbcIndex' from origin 'https://smartstore.abc.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin'
header is present on the requested resource.
I have verified that URL 'https://smartstore.abc.com' is present in <outboundrules> in web.config of WebAPI application
The quickest method is basic troubleshooting using the standard tools to debug your code. Open the browser's dev tools and review the request that caused the issue. Often the problem is the OPTIONS HTTP request is not CORS enabled or there is an error
returned by Web API.
Should we assume this is ASP.NET Web API and not Core?
whose operations are getting called from Angular client application.
For Angular applications, you can enable CORS through
proxy configuration. You need to generate a src/proxy.conf.json file in the Angular root folder and put the following code in it.
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Jan 21, 2021 11:02 AM|jainpratham27@gmail.com|LINK
Hi All,
The exact CORS error I am receiving from C# WebAPI application is:
Access to XMLHttpRequest at 'https://applicationservice.abc.com/api/ApplicationToken/ABCIndex' from origin 'https://smartstore.abc.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check:
It does not have HTTP ok status.
Yeah, we know the error and see folks with the error often on the forums. You are not the first or the last. Again, two most common issues are bugs in the action that cause an exception or an OPTIONS response that is not CORS enabled. this assumes you
actually configure CORS on the Web API application.
I provided a link in my first post which covers configuration as well as how to handle the OPTIONS request. It is not clear if you read the link.
If your Web API design is throwing an exception then you must fix the bug in your code. Use dev tools to view the request/response. If there is an error the response will contain the error message.
Member
3 Points
22 Posts
CORS Issue
Jan 20, 2021 05:19 PM|jainpratham27@gmail.com|LINK
Hi All,
I have a standard C# WebAPI project whose operations are getting called from Angular client application. This C# WebAPI application has CORS enabled on it. I am receiving the below error on entering the client application URL in browser:
Access to XMLHttpRequest at 'https://applicationservice.abc.com/api/AppToken/AbcIndex' from origin 'https://smartstore.abc.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
I have verified that URL 'https://smartstore.abc.com' is present in <outboundrules> in web.config of WebAPI application
<outboundRules>
<clear />
<rule name="AddCrossDomainHeader">
<match serverVariable="RESPONSE_Access_Control_Allow_Origin" pattern=".*" />
<conditions logicalGrouping="MatchAll" trackAllCaptures="true">
</conditions></rule></outboundrules>
Please suggest how can I resolve this issue ASAP.
Regards,
Pratham
All-Star
53041 Points
23617 Posts
Re: CORS Issue
Jan 20, 2021 06:20 PM|mgebhard|LINK
The quickest method is basic troubleshooting using the standard tools to debug your code. Open the browser's dev tools and review the request that caused the issue. Often the problem is the OPTIONS HTTP request is not CORS enabled or there is an error returned by Web API.
Should we assume this is ASP.NET Web API and not Core?
Reference
https://docs.microsoft.com/en-us/aspnet/web-api/overview/security/enabling-cross-origin-requests-in-web-api
Contributor
2740 Points
779 Posts
Re: CORS Issue
Jan 21, 2021 06:30 AM|YihuiSun|LINK
Hi jainpratham27,
For Angular applications, you can enable CORS through proxy configuration. You need to generate a src/proxy.conf.json file in the Angular root folder and put the following code in it.
You can click this link to see the solution.
{ "/api/*": { "target": "http://localhost:xxxxx", "secure": false, "logLevel": "debug" } }Best Regards,
YihuiSun
Member
3 Points
22 Posts
Re: CORS Issue
Jan 21, 2021 09:26 AM|jainpratham27@gmail.com|LINK
Hi mgeBhard,
Thanks for your quick reply! Yes, this is ASP.NET Web API project and not Core application.
Regards,
Pratham
Member
3 Points
22 Posts
Re: CORS Issue
Jan 21, 2021 11:02 AM|jainpratham27@gmail.com|LINK
Hi All,
The exact CORS error I am receiving from C# WebAPI application is:
Access to XMLHttpRequest at 'https://applicationservice.abc.com/api/ApplicationToken/ABCIndex' from origin 'https://smartstore.abc.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: It does not have HTTP ok status.
Regards,
Pratham
All-Star
53041 Points
23617 Posts
Re: CORS Issue
Jan 21, 2021 12:25 PM|mgebhard|LINK
Yeah, we know the error and see folks with the error often on the forums. You are not the first or the last. Again, two most common issues are bugs in the action that cause an exception or an OPTIONS response that is not CORS enabled. this assumes you actually configure CORS on the Web API application.
I provided a link in my first post which covers configuration as well as how to handle the OPTIONS request. It is not clear if you read the link.
If your Web API design is throwing an exception then you must fix the bug in your code. Use dev tools to view the request/response. If there is an error the response will contain the error message.