New Criteria API

model/criteria/json.go

@@ -0,0 +1,117 @@
+package criteria
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+)
+
+type unmarshalConjunctionType []Expression
+
+func (uc *unmarshalConjunctionType) UnmarshalJSON(data []byte) error {
+	var raw []map[string]json.RawMessage
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return err
+	}
+
+	var es unmarshalConjunctionType
+	for _, e := range raw {
+		for k, v := range e {
+			k = strings.ToLower(k)
+			expr := unmarshalExpression(k, v)
+			if expr == nil {
+				expr = unmarshalConjunction(k, v)
+			}
+			if expr == nil {
+				return fmt.Errorf(`invalid expression key %s`, k)
+			}
+			es = append(es, expr)
+		}
+	}
+	*uc = es
+	return nil
+}
+
+func unmarshalExpression(opName string, rawValue json.RawMessage) Expression {
+	m := make(map[string]interface{})
+	err := json.Unmarshal(rawValue, &m)
+	if err != nil {
+		return nil
+	}
+	switch opName {
+	case "is":
+		return Is(m)
+	case "isnot":
+		return IsNot(m)
+	case "gt":
+		return Gt(m)
+	case "lt":
+		return Lt(m)
+	case "contains":
+		return Contains(m)
+	case "notcontains":
+		return NotContains(m)
+	case "startswith":
+		return StartsWith(m)
+	case "endswith":
+		return EndsWith(m)
+	case "intherange":
+		return InTheRange(m)
+	case "before":
+		return Before(m)
+	case "after":
+		return After(m)
+	case "inthelast":
+		return InTheLast(m)
+	case "notinthelast":
+		return NotInTheLast(m)
+	}
+	return nil
+}
+
+func unmarshalConjunction(conjName string, rawValue json.RawMessage) Expression {
+	var items unmarshalConjunctionType
+	err := json.Unmarshal(rawValue, &items)
+	if err != nil {
+		return nil
+	}
+	switch conjName {
+	case "any":
+		return Any(items)
+	case "all":
+		return All(items)
+	}
+	return nil
+}
+
+func marshalExpression(name string, value map[string]interface{}) ([]byte, error) {
+	if len(value) != 1 {
+		return nil, fmt.Errorf(`invalid %s expression length %d for values %v`, name, len(value), value)
+	}
+	b := strings.Builder{}
+	b.WriteString(`{"` + name + `":{`)
+	for f, v := range value {
+		j, err := json.Marshal(v)
+		if err != nil {
+			return nil, err
+		}
+		b.WriteString(`"` + f + `":`)
+		b.Write(j)
+		break
+	}
+	b.WriteString("}}")
+	return []byte(b.String()), nil
+}
+
+func marshalConjunction(name string, conj []Expression) ([]byte, error) {
+	aux := struct {
+		All []Expression `json:"all,omitempty"`
+		Any []Expression `json:"any,omitempty"`
+	}{}
+	if name == "any" {
+		aux.Any = conj
+	} else {
+		aux.All = conj
+	}
+	return json.Marshal(aux)
+}