OPTIONS preflight request
BACKGROUND: transmitting a background like a post request, an error, an error code 403 (not through the verification authority), the method becomes a viewing request OPTIONS. Check the request header learned not to bring the current request token, the question of why post request into a request options?
What are the options request? When the browser sends a preflight request
options is a preflight request, before the actual request is sent, the browser will first send a request to ask the service options allow me to access the interface
browser requests in the current real simple and will request a non-pre-launch options under cross-domain situation inspection request
What is a simple request
1. The request method GET, POST, head
2.Content the Type-limited (file application / X-WWW-form-urlencoded, mutipart / form-Data, text / Plain)
3. not have a custom request header as xxx-token Wait
What is complex requests
A simple request that is non-complex request
1. Common Delete request method PUT
2.Content of the Type-file application / JSON
3. Add custom http header