LoadArray

mongox/common/loadarray.go

@@ -0,0 +1,73 @@
+package common
+
+import (
+	"reflect"
+
+	"github.com/mainnika/mongox-go-driver/mongox"
+	"github.com/mainnika/mongox-go-driver/mongox/errors"
+	"github.com/mainnika/mongox-go-driver/mongox/query"
+	"github.com/mongodb/mongo-go-driver/mongo/options"
+)
+
+// LoadArray loads an array of documents from the database by query
+func LoadArray(db *mongox.Database, target interface{}, composed *query.Query) error {
+
+	targetV := reflect.ValueOf(target)
+	targetT := targetV.Type()
+
+	targetK := targetV.Kind()
+	if targetK != reflect.Ptr {
+		panic(errors.InternalErrorf("target is not a ptr"))
+	}
+
+	targetSliceV := targetV.Elem()
+	targetSliceT := targetT.Elem()
+	if targetSliceT.Kind() != reflect.Slice {
+		panic(errors.InternalErrorf("target should be a ptr to a slice"))
+	}
+
+	targetSliceElemT := targetSliceT.Elem()
+	if targetSliceElemT.Kind() != reflect.Ptr {
+		panic(errors.InternalErrorf("target slice should contain ptrs"))
+	}
+
+	dummy := reflect.Zero(targetSliceElemT)
+	collection := db.GetCollectionOf(dummy.Interface())
+	opts := &options.FindOptions{}
+
+	if composed.Sorter() != nil {
+		opts.Sort = composed.Sorter().Sort()
+	}
+	if composed.Limiter() != nil {
+		limit := int64(composed.Limiter().Limit())
+		opts.Limit = &limit
+	}
+
+	result, err := collection.Find(db.Context(), composed.M(), opts)
+	if err != nil {
+		return errors.InternalErrorf("can't create find result: %s", err)
+	}
+
+	defer result.Close(db.Context())
+	var i int
+
+	for i = 0; result.Next(db.Context()); i++ {
+		if targetSliceV.Len() == i {
+			elem := reflect.New(targetSliceElemT.Elem())
+			if result.Decode(elem.Interface()) != nil {
+				continue
+			}
+
+			targetSliceV = reflect.Append(targetSliceV, elem)
+			// currentv = currentv.Slice(0, currentv.Cap())
+			continue
+		}
+
+		result.Decode(targetSliceV.Index(i).Interface())
+	}
+
+	targetSliceV = targetSliceV.Slice(0, i)
+	targetV.Elem().Set(targetSliceV)
+
+	return nil
+}