-
- // Set the Accepts header for the server, depending on the dataType
- requestHeaders.accept = s.dataTypes[ 0 ] && s.accepts[ s.dataTypes[ 0 ] ] ?
- s.accepts[ s.dataTypes[ 0 ] ] + ( s.dataTypes[ 0 ] !== "*" ? ", */*; q=0.01" : "" ) :
- s.accepts[ "*" ];
-
- // Check for headers option
- for ( i in s.headers ) {
- requestHeaders[ i.toLowerCase() ] = s.headers[ i ];
+ if ( jQuery_etag[ s.url ] ) {
+ requestHeaders[ "if-none-match" ] = jQuery_etag[ s.url ];
+ }
+ }
+
+ // Set the Accepts header for the server, depending on the dataType
+ requestHeaders.accept = s.dataTypes[ 0 ] && s.accepts[ s.dataTypes[ 0 ] ] ?
+ s.accepts[ s.dataTypes[ 0 ] ] + ( s.dataTypes[ 0 ] !== "*" ? ", */*; q=0.01" : "" ) :
+ s.accepts[ "*" ];
+
+ // Check for headers option
+ for ( i in s.headers ) {
+ requestHeaders[ i.toLowerCase() ] = s.headers[ i ];
+ }
+
+ // Allow custom headers/mimetypes and early abort
+ if ( s.beforeSend && ( s.beforeSend.call( callbackContext , jXHR , s ) === false || state === 2 ) ) {
+
+ // Abort if not done already
+ done( 0 , "abort" );
+
+ // Return false
+ jXHR = false;
+
+ } else {
+
+ // Install callbacks on deferreds
+ for ( i in { success:1, error:1, complete:1 } ) {
+ jXHR[ i ]( s[ i ] );