Initial QSfera import

Server/vendor/github.com/CiscoM31/godata/orderby_parser.go

@@ -0,0 +1,102 @@
+package godata
+
+import (
+	"context"
+	"strings"
+)
+
+const (
+	ASC  = "asc"
+	DESC = "desc"
+)
+
+type OrderByItem struct {
+	Field *Token            // The raw value of the orderby field or expression.
+	Tree  *GoDataExpression // The orderby expression parsed as a tree.
+	Order string            // Ascending or descending order.
+}
+
+func ParseOrderByString(ctx context.Context, orderby string) (*GoDataOrderByQuery, error) {
+	return GlobalExpressionParser.ParseOrderByString(ctx, orderby)
+}
+
+// The value of the $orderby System Query option contains a comma-separated
+// list of expressions whose primitive result values are used to sort the items.
+// The service MUST order by the specified property in ascending order.
+// 4.01 services MUST support case-insensitive values for asc and desc.
+func (p *ExpressionParser) ParseOrderByString(ctx context.Context, orderby string) (*GoDataOrderByQuery, error) {
+	items := strings.Split(orderby, ",")
+
+	result := make([]*OrderByItem, 0)
+
+	for _, v := range items {
+		v = strings.TrimSpace(v)
+
+		cfg, hasComplianceConfig := ctx.Value(odataCompliance).(OdataComplianceConfig)
+		if !hasComplianceConfig {
+			// Strict ODATA compliance by default.
+			cfg = ComplianceStrict
+		}
+
+		if len(v) == 0 && cfg&ComplianceIgnoreInvalidComma == 0 {
+			return nil, BadRequestError("Extra comma in $orderby.")
+		}
+
+		var order string
+		vLower := strings.ToLower(v)
+		if strings.HasSuffix(vLower, " "+ASC) {
+			order = ASC
+		} else if strings.HasSuffix(vLower, " "+DESC) {
+			order = DESC
+		}
+		if order == "" {
+			order = ASC // default order
+		} else {
+			v = v[:len(v)-len(order)]
+			v = strings.TrimSpace(v)
+		}
+
+		if tree, err := p.ParseExpressionString(ctx, v); err != nil {
+			switch e := err.(type) {
+			case *GoDataError:
+				return nil, &GoDataError{
+					ResponseCode: e.ResponseCode,
+					Message:      "Invalid $orderby query option",
+					Cause:        e,
+				}
+			default:
+				return nil, &GoDataError{
+					ResponseCode: 500,
+					Message:      "Invalid $orderby query option",
+					Cause:        e,
+				}
+			}
+		} else {
+			result = append(result, &OrderByItem{
+				Field: &Token{Value: unescapeUtfEncoding(v)},
+				Tree:  tree,
+				Order: order,
+			})
+
+		}
+	}
+
+	return &GoDataOrderByQuery{result, orderby}, nil
+}
+
+func SemanticizeOrderByQuery(orderby *GoDataOrderByQuery, service *GoDataService, entity *GoDataEntityType) error {
+	if orderby == nil {
+		return nil
+	}
+
+	for _, item := range orderby.OrderByItems {
+		if prop, ok := service.PropertyLookup[entity][item.Field.Value]; ok {
+			item.Field.SemanticType = SemanticTypeProperty
+			item.Field.SemanticReference = prop
+		} else {
+			return BadRequestError("No property " + item.Field.Value + " for entity " + entity.Name)
+		}
+	}
+
+	return nil
+}