[update] predicates

Author: epoddubskij

sql.go

@@ -29,13 +29,24 @@ type Filter struct {
 	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, []interface{}) (string, []interface{}, 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) {
@@ -57,15 +68,6 @@ func inSQL(field string, data []interface{}, db DBDriver) (string, []interface{}
 	return sql, data, nil
 }
 
-func (f *Filter) getValues() []interface{} {
-	valueMap, ok := f.Value.(map[string]interface{})
-	if !ok {
-		return []interface{}{f.Value}
-	}
-
-	return []interface{}{valueMap["start"], valueMap["end"]}
-}
-
 func GetSQL(data Filter, config *SQLConfig, dbArr ...DBDriver) (string, []interface{}, error) {
 	var db DBDriver
 	if len(dbArr) > 0 {
@@ -90,6 +92,17 @@ func GetSQL(data Filter, config *SQLConfig, dbArr ...DBDriver) (string, []interf
 		}
 
 		values := data.getValues()
+
+		var err error
+		if config != nil && config.Predicates != nil {
+			if pr, prOk := config.Predicates[data.Predicate]; prOk {
+				name, values, err = pr(name, data.Predicate, values)
+				if err != nil {
+					return "", NoValues, err
+				}
+			}
+		}
+
 		switch data.Filter {
 		case "":
 			return "", NoValues, nil
@@ -144,8 +157,7 @@ func GetSQL(data Filter, config *SQLConfig, dbArr ...DBDriver) (string, []interf
 		}
 
 		if config != nil && config.Operations != nil {
-			op, opOk := config.Operations[data.Filter]
-			if opOk {
+			if op, opOk := config.Operations[data.Filter]; opOk {
 				return op(name, data.Filter, values)
 			}
 		}

sql_test.go

@@ -11,6 +11,7 @@ var aAndB = `{ "glue":"and", "rules":[{ "field": "a", "filter":"less", "value":1
 var aOrB = `{ "glue":"or", "rules":[{ "field": "a", "filter":"less", "value":1}, { "field": "b", "filter":"greater", "value":"abc" }]}`
 var cOrC = `{ "glue":"or", "rules":[{ "field": "a", "filter":"is null" }, { "field": "b", "filter":"range100", "value":500 }]}`
 var JSONaAndB = `{ "glue":"and", "rules":[{ "field": "json:cfg.a", "filter":"less", "value":1}, { "field": "json:cfg.b", "filter":"greater", "value":"abc" }]}`
+var aPred = `{ "glue":"and", "rules":[{ "field": "a", "filter":"greater", "type": "number", "predicate": "month","value": 10 }, { "field": "a", "filter":"less", "type": "number", "predicate": "year","value": 2024 }]}`
 
 var cases = [][]string{
 	{`{}`, "", "", ""},
@@ -447,7 +448,7 @@ func TestWhitelistPG(t *testing.T) {
 func TestCustomOperation(t *testing.T) {
 	format, err := FromJSON([]byte(cOrC))
 	if err != nil {
-		t.Errorf("can't parse json\nj: %s\n%f", aAndB, err)
+		t.Errorf("can't parse json\nj: %s\n%f", cOrC, err)
 		return
 	}
 
@@ -486,3 +487,87 @@ func TestCustomOperation(t *testing.T) {
 		return
 	}
 }
+
+func TestCustomPredicate(t *testing.T) {
+	format, err := FromJSON([]byte(aPred))
+	if err != nil {
+		t.Errorf("can't parse json\nj: %s\n%f", aPred, err)
+		return
+	}
+
+	sql, vals, err := GetSQL(format, &SQLConfig{
+		Predicates: map[string]CustomPredicate{
+			"month": func(n string, p string, values []interface{}) (string, []interface{}, error) {
+				return fmt.Sprintf("month(%s)", n), values, nil
+			},
+			"year": func(n string, p string, values []interface{}) (string, []interface{}, error) {
+				return fmt.Sprintf("year(%s)", n), values, nil
+			},
+		},
+	})
+
+	if err != nil {
+		t.Errorf("can't generate sql: %s\n%f", aPred, err)
+		return
+	}
+
+	check := "( month(a) > ? AND year(a) < ? )"
+	if sql != check {
+		t.Errorf("wrong sql generated\nj: %s\ns: %s\nr: %s", aPred, check, sql)
+		return
+	}
+
+	valsStr, err := anyToStringArray(vals)
+	if err != nil {
+		t.Errorf("can't convert parameters\nj: %s\n%f", aPred, err)
+		return
+	}
+
+	check = "10,2024"
+	if valsStr != check {
+		t.Errorf("wrong sql generated\nj: %s\ns: %s\nr: %s", aPred, check, valsStr)
+		return
+	}
+}
+
+func TestCustomPredicatePG(t *testing.T) {
+	format, err := FromJSON([]byte(aPred))
+	if err != nil {
+		t.Errorf("can't parse json\nj: %s\n%f", aPred, err)
+		return
+	}
+
+	sql, vals, err := GetSQL(format, &SQLConfig{
+		Predicates: map[string]CustomPredicate{
+			"month": func(n string, p string, values []interface{}) (string, []interface{}, error) {
+				return fmt.Sprintf("date_part('month', %s)", n), values, nil
+			},
+			"year": func(n string, p string, values []interface{}) (string, []interface{}, error) {
+				return fmt.Sprintf("date_part('year', %s)", n), values, nil
+			},
+		},
+	}, &PostgreSQL{})
+
+	if err != nil {
+		t.Errorf("can't generate sql: %s\n%f", aPred, err)
+		return
+	}
+
+	check := "( date_part('month', a) > $1 AND date_part('year', a) < $2 )"
+	if sql != check {
+		t.Errorf("wrong sql generated\nj: %s\ns: %s\nr: %s", aPred, check, sql)
+		return
+	}
+
+	valsStr, err := anyToStringArray(vals)
+	if err != nil {
+		t.Errorf("can't convert parameters\nj: %s\n%f", aPred, err)
+		return
+	}
+
+	check = "10,2024"
+	if valsStr != check {
+		t.Errorf("wrong sql generated\nj: %s\ns: %s\nr: %s", aPred, check, valsStr)
+		return
+	}
+}