Ajax and Comet

1.Ajax core?

Xhr

>>1. New XMLHttpRequest

>>2.open (), accepts 3 parameters.

>>3.send (), accepts 1 parameters.

>>4. When a server response is received, the response data is automatically populated with the properties of the Xhr object.

ResponseText

Responsexml

Status

StatusText

>> Sync requests, receive responses, check the following in order: status attribute; responsetext;responsexml;

>> asynchronous request, receive response, check the following: Readystatus

2.HTTP Header Information

Setrequeseheader (); Sets the custom request header information, 2 parameters, Key,value.

Getrequeseheader (); 1 parameters, header field name

Getallrequeseheaders (); Get All header information

3.

　　　　

　　

Ajax and Comet