I'm creating a web appliacation that will run on a server that I can not manage nor modify in any case.
Within that application, I need to exceute a AJAX call to a different server.
This will always be blocked by the 'Same Origin Policy'.
Where server01.test.net is the webserver and mail.test.net is the second server.
Is there a way to enable CORS by any means in the client side, as I'm not able to add the 'Access-Control-Allow-Origin "*"' on the server. Or any other workaournd?
Thanks
CORS is an option with the SERVER. In no way client can by themselves enable CORS.
If client would have been allowed to do that, the whole purpose of CORS would be defeated.
If the server you are calling does not support CORS, you will not be able to make the request to the third-party server using AJAX.
You will have to resort to setting up a pass-through AJAX route in your application. The client (browser) makes a request to your AJAX route which proxies the call to the third-party server and returns the result. Because the third-party request is happening on the server rather than the browser, Same Origin Policy doesn't apply.
This approach means there will be an additional request that wouldn't be necessary if you could use CORS, but there really isn't another option.
Related
I am using Postal PIN Code API for getting Post Office(s) details search by Postal PIN Code in angular 5 application. Below is the url of the external API :
http://postalpincode.in/api/pincode/{**PINCODE}**
I am issuing a GET request from the application but it is giving me below error :
No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:4200' is therefore not allowed access
Although this request is working perfectly fine from browser and postman. I understand that we need to configure our server with cross-domain policies for accepting cross-domain request but this is an external API and I don't have control over it. How can I resolve this issue?
Thanks in Advance !!
Best: CORS header (requires server changes) CORS (Cross-Origin Resource Sharing) is a way for the server to say “I will accept your request, even though you came from a different origin.” This requires cooperation from the server – so if you can’t modify the server (e.g. if you’re using an external API), this approach won’t work.
Modify the server to add the header Access-Control-Allow-Origin: * to enable cross-origin requests from anywhere (or specify a domain instead of *). This should solve your problem.
2nd choice: Proxy Server If you can’t modify the server, you can run your own proxy. And this proxy can return the Access-Control-Allow-Origin header if it’s not at the Same Origin as your page.
Instead of sending API requests to some remote server, you’ll make requests to your proxy, which will forward them to the remote server.
Here are a few proxy options.
Ref: https://daveceddia.com/access-control-allow-origin-cors-errors-in-angular/
I want to call REST-services from my Angular-app. However, these REST-services are hosted on WLP and are part of a WAR-file developed by some company a while ago, ie. we have no source code.
I can call GET-methods without any issues from Postman, I just need to set authentication and accept headers. However, calling these GET-methods from Angular via web browsers will trigger preflight request (OPTIONS) without Authentication header prop. Seems to me that OPTIONS requests are triggered by the browsers and Angular cannot set headers for them. I confirmed OPTIONS requests need authentication by running requests via Postman with and without auth header prop.
Similar problems were discussed in other posts on stackoverflow but in such cases people had control over their server side code and could alter it to avoid authentication headers for OPTIONS request. Clearly in my case, I cannot do it.
My question is if there is a possibility to configure WLP to not ask for authentication header prop in case of OPTIONS-requests (seems to be configurable for Apache web servers and Tomcat)?
Kind regards
A.H.
Even without source, you should be able to edit web.xml and modify the security-constraints to punch a hole for OPTIONS.
I've a server named, foo.com where my application is running and accessing a service available on a different domain bar.foo.com.
With the simple XHR request to bar.foo.com/getUsers, I'm getting an error saying, No 'Access-Control-Allow-Origin' header is present. I do not want to use JSONP as a fallback to cross-domain issue.
Is there any easy fix I can do on server level to enable cross subdomain requests while XHRing?
It appears that I need to set allow-cross-domain headers on server when a response is returned as suggested by #Blender above.
Or I can use xdomain library which uses PostMessage API to enable cors. With this I can even read iframe's content served by different domain.
I plan to use https to build a website. After the user logs in, s/he is directed to a dashboard. The dashboard will be developed using javascript and html5. What are the thing I need to keep in mind when I make ajax calls using SOAP to a web service while using https?
The most important things:
always use the same domain name, otherwise browser will throw cross domain errors,
always use https protocol for every ajax request, so browser won't get same origin errors.
On the server side check for X-Requested-With: XMLHttpRequest HTTP header, to be sure that the request came as AJAX, not standalone GET/POST request. This is only difference.
With AJAX request browser will send the same cookies value as in the any other request, so you can surely check user session with it.
Assuming a single page application accessed initially via HTTP that uses AJAX for all server interaction, is it possible to use HTTP for regular data transfers and then switch to AJAXian HTTPS requests for secure data transfers?
If so, how would the browser handle the certificate and locking notification when a HTTPS AJAX request was made?
If this is not possible, then are there any workarounds to mixing AJAX HTTP and AJAX HTTPS within the same page such as loading an iFrame for HTTPS?
Thanks!
Attempting to switch protocols will violate the same origin policy.
I am not sure how a workaround using iFrames would behave, but I think the browser may block access to the frame that was loaded as HTTPS, again due to the same origin policy.
I know this is old post but since i arrived here by search engine it would be a worth to spill what I've learn.
It is possible to use something called CORS but as usual old MSIE has problem implementing it.
It should be simple as sending additional HTTP headers:
Access-Control-Allow-Origin: http://example.com:8080 http://foo.example.com