This article implements cross-domain by setting up Access-control-allow-origin .
For example: The domain name of the client is client.runoob.com, and the requested domain name is server.runoob.com.
If you use AJAX access directly, you will get the following error:
XMLHttpRequest cannot load http://server.runoob.com/server.php. No ' Access-control-allow-origin ' header is present on the requested resource. Origin ' http://client.runoob.com ' is therefore not allowed access.
1. Allow single domain access
To specify a domain name (http://client.runoob.com) for cross-domain access, simply add the following code to the http://server.runoob.com/server.php file header:
Header (' access-control-allow-origin:http://client.runoob.com ');
2. Allow multiple domain names to be accessed
To specify multiple domain names (http://client1.runoob.com, http://client2.runoob.com, and so on) for cross-domain access, simply add the following code to the http://server.runoob.com/server.php file header:
$origin isset ($_server$_server[' Http_origin ']: '; $allow _origin Array ( ' http://client1.runoob.com ', ' http://client2.runoob.com ' ); if (in_array($origin$allow _origin)) { header(' Access-control-allow-origin: '. $origin );
3. Allow all domain names to access
To allow all domain access, simply add the following code to the http://server.runoob.com/server.php file header:
Header
PHP Ajax the best solution for cross-domain problems