added ErrorWithStack

crud.go

@@ -3,6 +3,7 @@ package mgocrud
 import (
 	"fmt"
 	"reflect"
+	"runtime/debug"
 	"strings"
 	"time"
 
@@ -11,6 +12,19 @@ import (
 	"gopkg.in/mgo.v2/bson"
 )
 
+type ErrorWithStack struct {
+	Message    string
+	StackTrace string
+}
+
+func (e *ErrorWithStack) Error() string {
+	return e.Message
+}
+
+func (e *ErrorWithStack) Stack() string {
+	return e.StackTrace
+}
+
 // CreateDocument creates a document from specified model
 func CreateDocument(db *mgo.Database, m ModelInterface) error {
 	m.PrepareInsert()
@@ -116,10 +130,10 @@ func idToObjectID(filter interface{}) {
 }
 
 // ReadCollection gets the filtered collection of the model
-func ReadCollection(db *mgo.Database, results interface{}, filter bson.M, selector bson.M, offset int, limit int, sort []string, pipelineModifier PipelineModifierFunction) (err error) {
+func ReadCollection(db *mgo.Database, results interface{}, filter bson.M, selector bson.M, offset int, limit int, sort []string, pipelineModifier PipelineModifierFunction) (err *ErrorWithStack) {
 	defer func() {
 		if r := recover(); r != nil {
-			err = fmt.Errorf("%v", r)
+			err = &ErrorWithStack{Message: fmt.Sprintf("%v", r), StackTrace: string(debug.Stack())}
 		}
 	}()
 
@@ -142,6 +156,8 @@ func ReadCollection(db *mgo.Database, results interface{}, filter bson.M, select
 
 	c := db.C(GetCollectionName(m))
 
+	var _err error
+
 	if pipelineModifier != nil {
 		// search via pipeline
 
@@ -190,7 +206,7 @@ func ReadCollection(db *mgo.Database, results interface{}, filter bson.M, select
 		}
 
 		q := c.Pipe(pipeline).AllowDiskUse().Iter()
-		err = q.All(results)
+		_err = q.All(results)
 	} else {
 		// search without pipe is faster
 
@@ -212,9 +228,12 @@ func ReadCollection(db *mgo.Database, results interface{}, filter bson.M, select
 			q = q.Limit(limit)
 		}
 
-		err = q.All(results)
+		_err = q.All(results)
 	}
 
+	if _err != nil {
+		return &ErrorWithStack{Message: _err.Error(), StackTrace: string(debug.Stack())}
+	}
 	return err
 }