Merge pull request #7 from xbsoftware/dev-alternative-type

[dev] alternative type

Author: mkozhukh

condition.go

@@ -21,18 +21,32 @@ type DBDriver interface {
 type Filter struct {
 	Glue      string        `json:"glue"`
 	Field     string        `json:"field"`
-	Condition Condition     `json:"condition"`
+	Type      string        `json:"type"`
+	Predicate string        `json:"predicate"`
+	Filter    string        `json:"filter"`
+	Value     interface{}   `json:"value"`
 	Includes  []interface{} `json:"includes"`
-	Kids      []Filter      `json:"rules"`
+	Rules     []Filter      `json:"rules"`
+}
+
+func (f *Filter) getValues() []interface{} {
+	valueMap, ok := f.Value.(map[string]interface{})
+	if !ok {
+		return []interface{}{f.Value}
+	}
+
+	return []interface{}{valueMap["start"], valueMap["end"]}
 }
 
 type CustomOperation func(string, string, []interface{}) (string, []interface{}, error)
+type CustomPredicate func(string, string) (string, error)
 
 type CheckFunction = func(string) bool
 type SQLConfig struct {
 	WhitelistFunc CheckFunction
 	Whitelist     map[string]bool
 	Operations    map[string]CustomOperation
+	Predicates    map[string]CustomPredicate
 }
 
 func FromJSON(text []byte) (Filter, error) {
@@ -62,7 +76,7 @@ func GetSQL(data Filter, config *SQLConfig, dbArr ...DBDriver) (string, []interf
 		db = MySQL{}
 	}
 
-	if data.Kids == nil {
+	if data.Rules == nil {
 		if data.Field == "" {
 			return "", make([]interface{}, 0), nil
 		}
@@ -77,8 +91,21 @@ func GetSQL(data Filter, config *SQLConfig, dbArr ...DBDriver) (string, []interf
 			return inSQL(name, data.Includes, db)
 		}
 
-		values := data.Condition.getValues()
-		switch data.Condition.Rule {
+		values := data.getValues()
+
+		var err error
+		if config != nil && config.Predicates != nil {
+			if pr, prOk := config.Predicates[data.Predicate]; prOk {
+				name, err = pr(name, data.Predicate)
+				if err != nil {
+					return "", NoValues, err
+				}
+			} else {
+				return "", NoValues, fmt.Errorf("unknown predicate: %s", data.Predicate)
+			}
+		}
+
+		switch data.Filter {
 		case "":
 			return "", NoValues, nil
 		case "equal":
@@ -132,19 +159,18 @@ func GetSQL(data Filter, config *SQLConfig, dbArr ...DBDriver) (string, []interf
 		}
 
 		if config != nil && config.Operations != nil {
-			op, opOk := config.Operations[data.Condition.Rule]
-			if opOk {
-				return op(name, data.Condition.Rule, data.Condition.getValues())
+			if op, opOk := config.Operations[data.Filter]; opOk {
+				return op(name, data.Filter, values)
 			}
 		}
 
-		return "", NoValues, fmt.Errorf("unknown operation: %s", data.Condition.Rule)
+		return "", NoValues, fmt.Errorf("unknown operation: %s", data.Filter)
 	}
 
-	out := make([]string, 0, len(data.Kids))
+	out := make([]string, 0, len(data.Rules))
 	values := make([]interface{}, 0)
 
-	for _, r := range data.Kids {
+	for _, r := range data.Rules {
 		subSql, subValues, err := GetSQL(r, config, db)
 		if err != nil {
 			return "", nil, err
@@ -161,7 +187,7 @@ func GetSQL(data Filter, config *SQLConfig, dbArr ...DBDriver) (string, []interf
 	}
 
 	outStr := strings.Join(out, glue)
-	if len(data.Kids) > 1 {
+	if len(data.Rules) > 1 {
 		outStr = "( " + outStr + " )"
 	}