forked from pocketbase/pocketbase
/
sort.go
59 lines (48 loc) · 1.45 KB
/
sort.go
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package search
import (
"fmt"
"strings"
)
const randomSortKey string = "@random"
// sort field directions
const (
SortAsc string = "ASC"
SortDesc string = "DESC"
)
// SortField defines a single search sort field.
type SortField struct {
Name string `json:"name"`
Direction string `json:"direction"`
}
// BuildExpr resolves the sort field into a valid db sort expression.
func (s *SortField) BuildExpr(fieldResolver FieldResolver) (string, error) {
// special case for random sort
if s.Name == randomSortKey {
return "RANDOM()", nil
}
result, err := fieldResolver.Resolve(s.Name)
// invalidate empty fields and non-column identifiers
if err != nil || len(result.Params) > 0 || result.Identifier == "" || strings.ToLower(result.Identifier) == "null" {
return "", fmt.Errorf("invalid sort field %q", s.Name)
}
return fmt.Sprintf("%s %s", result.Identifier, s.Direction), nil
}
// ParseSortFromString parses the provided string expression
// into a slice of SortFields.
//
// Example:
//
// fields := search.ParseSortFromString("-name,+created")
func ParseSortFromString(str string) (fields []SortField) {
data := strings.Split(str, ",")
for _, field := range data {
// trim whitespaces
field = strings.TrimSpace(field)
if strings.HasPrefix(field, "-") {
fields = append(fields, SortField{strings.TrimPrefix(field, "-"), SortDesc})
} else {
fields = append(fields, SortField{strings.TrimPrefix(field, "+"), SortAsc})
}
}
return
}