Merge pull request #594 from mschoch/add-blevetype

add support for BleveType() alternative for type detection

index.go

@@ -110,12 +110,15 @@ func (b *Batch) Reset() {
 // them.
 //
 // The DocumentMapping used to index a value is deduced by the following rules:
-// 1) If value implements Classifier interface, resolve the mapping from Type().
-// 2) If value has a string field or value at IndexMapping.TypeField.
+// 1) If value implements mapping.bleveClassifier interface, resolve the mapping
+//    from BleveType().
+// 2) If value implements mapping.Classifier interface, resolve the mapping
+//    from Type().
+// 3) If value has a string field or value at IndexMapping.TypeField.
 // (defaulting to "_type"), use it to resolve the mapping. Fields addressing
 // is described below.
-// 3) If IndexMapping.DefaultType is registered, return it.
-// 4) Return IndexMapping.DefaultMapping.
+// 4) If IndexMapping.DefaultType is registered, return it.
+// 5) Return IndexMapping.DefaultMapping.
 //
 // Each field or nested field of the value is identified by a string path, then
 // mapped to one or several FieldMappings which extract the result for analysis.

mapping/index.go

@@ -289,7 +289,12 @@ func (im *IndexMappingImpl) UnmarshalJSON(data []byte) error {
 }
 
 func (im *IndexMappingImpl) determineType(data interface{}) string {
-	// first see if the object implements Classifier
+	// first see if the object implements bleveClassifier
+	bleveClassifier, ok := data.(bleveClassifier)
+	if ok {
+		return bleveClassifier.BleveType()
+	}
+	// next see if the object implements Classifier
 	classifier, ok := data.(Classifier)
 	if ok {
 		return classifier.Type()

mapping/mapping.go

@@ -22,12 +22,21 @@ import (
 	"github.com/blevesearch/bleve/document"
 )
 
-// A Classifier is an interface describing any object
-// which knows how to identify its own type.
+// A Classifier is an interface describing any object which knows how to
+// identify its own type.  Alternatively, if a struct already has a Type
+// field or method in conflict, one can use BleveType instead.
 type Classifier interface {
 	Type() string
 }
 
+// A bleveClassifier is an interface describing any object which knows how
+// to identify its own type.  This is introduced as an alternative to the
+// Classifier interface which often has naming conflicts with existing
+// structures.
+type bleveClassifier interface {
+	BleveType() string
+}
+
 var logger = log.New(ioutil.Discard, "bleve mapping ", log.LstdFlags)
 
 // SetLog sets the logger used for logging