Custom web api calling through JQuery showing CORS error in sharePoint 2019 onpremise.

Question

Custom web api calling through JQuery showing CORS error in sharePoint 2019 onpremise.

Answer 1

Hi @Mohammad Javed ,

This is a CORS issue. Only when the protocol, host and port is the same, then it could be considered as the Same Origin Policy.

You may need to modify some settings on the Web config file or rewrite the IIS rules. Please check below similar thread:

• https://social.msdn.microsoft.com/Forums/office/en-US/cea8a653-f805-4ff7-8407-1b89dadbfed2/sharepoint-cross-domain-issue-edge-browser?forum=sharepointdevelopment

If you want to exactly math the specified url, you can change the catch url condition in inbound rule like below:

<rules>  
        <rule name="inboundrule" patternSyntax="ECMAScript" stopProcessing="true">  
          <match url=".*" />  
          <conditions logicalGrouping="MatchAll">  
                        <add input="{HTTP_ORIGIN}" pattern="(http(s)?://((.+\.)?andyweb2\.azurewebsites\.net|(.+\.)?ggg\.devchatline\.com))" />  
                        <add input="{REQUEST_METHOD}" pattern="^OPTIONS$" />  
          </conditions>  
          <action type="CustomResponse" statusCode="200" statusReason="Preflight" statusDescription="Preflights" />  
        </rule>  
</rules>  

*Note that not forgot to replace the pattern with your own value.

More reference:

• https://social.technet.microsoft.com/Forums/en-US/9ae5ea28-5e46-4192-953d-d6142b1d060a/cors-change-in-sharepoint-server-2016?forum=SP2016

Best Regards,
Baker Kong

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