+ if ( jQuery.isFunction( func ) ) {
+ var dataTypes = dataTypeExpression.split( rspacesAjax ),
+ i = 0,
+ length = dataTypes.length,
+ dataType,
+ list,
+ placeBefore;
+
+ // For each dataType in the dataTypeExpression
+ for(; i < length; i++ ) {
+ dataType = dataTypes[ i ];
+ // We control if we're asked to add before
+ // any existing element
+ placeBefore = /^\+/.test( dataType );
+ if ( placeBefore ) {
+ dataType = dataType.substr( 1 );
+ }
+ list = structure[ dataType ] = structure[ dataType ] || [];
+ // then we add to the structure accordingly
+ list[ placeBefore ? "unshift" : "push" ]( func );
+ }
+ }
+ };
+}
+
+//Base inspection function for prefilters and transports
+function inspectPrefiltersOrTransports( structure, options, originalOptions, jXHR,
+ dataType /* internal */, inspected /* internal */ ) {
+
+ dataType = dataType || options.dataTypes[ 0 ];
+ inspected = inspected || {};
+
+ inspected[ dataType ] = true;
+
+ var list = structure[ dataType ],
+ i = 0,
+ length = list ? list.length : 0,
+ executeOnly = ( structure === prefilters ),
+ selection;
+
+ for(; i < length && ( executeOnly || !selection ); i++ ) {
+ selection = list[ i ]( options, originalOptions, jXHR );
+ // If we got redirected to another dataType
+ // we try there if not done already
+ if ( typeof selection === "string" ) {
+ if ( inspected[ selection ] ) {
+ selection = undefined;
+ } else {
+ options.dataTypes.unshift( selection );
+ selection = inspectPrefiltersOrTransports(
+ structure, options, originalOptions, jXHR, selection, inspected );
+ }
+ }
+ }
+ // If we're only executing or nothing was selected
+ // we try the catchall dataType if not done already
+ if ( ( executeOnly || !selection ) && !inspected[ "*" ] ) {
+ selection = inspectPrefiltersOrTransports(
+ structure, options, originalOptions, jXHR, "*", inspected );
+ }
+ // unnecessary when only executing (prefilters)
+ // but it'll be ignored by the caller in that case
+ return selection;
+}