“Cross-Origin Request Blocked” - how to bypass for REST queries

Question

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource"

I'm trying to use REST api to query a library to find all the file names in it so that I can populate a dropdown on another site. This apparently violates the CORS policy. How do I get around this since I can't modify the code that SharePoint is using?

I'm using this endpoint: "https:/xxx/sites/xxx/_api/Web/GetFolderByServerRelativeUrl('/sites/yyyy/Database%20documents/" + folderName + "')/files?$select=Name")

Answer 1

I had your same problem.

SP.RequestExecutor() needs a SharePoint App environment to work.

the ONLY path that solved my problem was to use URL Rewrite on IIS, editing also the jQuery ajax call.

Answer 2

Thats a security Feature of modern Browsers. You can´t do a Request to another Domain using Javascript. The only Thing you could to is to add a "Access-Control-Allow-Origin" Header to the Webservers (SharePoint) Response. However, if you do not have this possibility, there is no way.

Answer 3

Assuming you are using JSOM

First you need to create object of SP.RequestExecutor() Than you can call cross domain url by using executor.executeAsync()

For more info follow this

For example:

$.getScript(scriptbase + "/_layouts/15/SP.RequestExecutor.js", myFunction);
}); //scriptbase -- > your host web url, which can be fetch from query string

function myFunction(){
 var executor=new SP.RequestExecutor(appWebUrl); //pass app web url

       executor.executeAsync(
            {
                url: myUrl,
                type: "GET",
                headers: { "Accept": "application/json; odata=verbose" },
                success: function (data) {
                    //success handler
                    },
                error: function (xhr) {
                   // error handler
                }
            });
}