Our organization has a data collection on their servers. A soap API has been implemented and the data can be accessed using the WSDL on SOAP UI. I am a front-end developer and when I make a POST request using XMLHttpRequest to get the query result, it throws CORS error: "Response to the preflight request doesn't pass access control". It is NOT possible to enable CORS on the data collection servers. I am using Liferay for the website front end and the back end.
Any suggestions how I can get the query results from the front end without enabling CORS on database servers(this is different than the Liferay backend server)? Or I can use a website backend to interact with the database? Or use third-party services like Kinvey?
I have had similar issues in the past. Like you, I wanted to create a basic webpage on my machine and that contained some Javascript to call an API. With this approach, I got the CORS issue you are seeing.
I then hosted my page on a web-server and I still got the CORS issue.
To resolve, I had to create a web app, which I wrote in Java. This back-end contained its own API. One of the resources in 'my' API was a simple wrapper to call the API of interest. I then modified the webpage I wrote (now all hosted in the same web app), to call my API, which in turn calls the API of interest.