feat: add ConditionToGormQuery() API (#210)

* feat: ConditionToGormQuery

* fix: delete local test

* fix: import sort

Author: PokIsemaine

README.md

@@ -149,6 +149,81 @@ func main() {
 	}
 }
 ```
+## ConditionsToGormQuery
+
+`ConditionsToGormQuery()` is a function that converts multiple query conditions into a GORM query statement
+You can use the `GetAllowedObjectConditions()` API of Casbin to get conditions,
+and choose the way of combining conditions through `combineType`.
+
+`ConditionsToGormQuery()` allows Casbin to be combined with SQL, and you can use it to implement many functions.
+### Example: GetAllowedRecordsForUser
+* model example: [object_conditions_model.conf](examples/object_conditions_model.conf)
+* policy example: [object_conditions_policy.csv](examples/object_conditions_policy.csv)
+
+DataBase example:
+
+|id|title|author|publisher|publish_data|price|category_id|
+|--|--|--|--|--|--|--|
+|1|book1|author1|publisher1|2023-04-09 16:23:42|10|1|
+|2|book2|author1|publisher1|2023-04-09 16:23:44|20|2|
+|3|book3|author2|publisher1|2023-04-09 16:23:44|30|1|
+|4|book4|author2|publisher2|2023-04-09 16:23:45|10|3|
+|5|book5|author3|publisher2|2023-04-09 16:23:45|50|1|
+|6|book6|author3|publisher2|2023-04-09 16:23:46|60|2|
+
+
+```go
+type Book struct {
+    ID          int
+    Title       string
+    Author      string
+    Publisher   string
+    PublishDate time.Time
+    Price       float64
+    CategoryID  int
+}
+
+func TestGetAllowedRecordsForUser(t *testing.T) {
+	e, _ := casbin.NewEnforcer("examples/object_conditions_model.conf", "examples/object_conditions_policy.csv")
+
+	conditions, err := e.GetAllowedObjectConditions("alice", "read", "r.obj.")
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println(conditions)
+
+	dsn := "root:root@tcp(127.0.0.1:3307)/test?charset=utf8mb4&parseTime=True&loc=Local"
+	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println("CombineTypeOr")
+	rows, err := ConditionsToGormQuery(db, conditions, CombineTypeOr).Model(&Book{}).Rows()
+	defer rows.Close()
+	var b Book
+	for rows.Next() {
+		err := db.ScanRows(rows, &b)
+		if err != nil {
+			panic(err)
+		}
+		log.Println(b)
+	}
+
+	fmt.Println("CombineTypeAnd")
+	rows, err = ConditionsToGormQuery(db, conditions, CombineTypeAnd).Model(&Book{}).Rows()
+	defer rows.Close()
+	for rows.Next() {
+		err := db.ScanRows(rows, &b)
+		if err != nil {
+			panic(err)
+		}
+		log.Println(b)
+	}
+}
+```
+
+
 ## Getting Help
 
 - [Casbin](https://github.com/casbin/casbin)

adapter.go

@@ -977,3 +977,27 @@ func (c *CasbinRule) toStringPolicy() []string {
 	}
 	return policy
 }
+
+// CombineType represents different types of condition combining strategies
+type CombineType uint32
+
+const (
+	CombineTypeOr  CombineType = iota // Combine conditions with OR operator
+	CombineTypeAnd                    // Combine conditions with AND operator
+)
+
+// ConditionsToGormQuery is a function that converts multiple query conditions into a GORM query statement
+// You can use the GetAllowedObjectConditions() API of Casbin to get conditions,
+// and choose the way of combining conditions through combineType.
+func ConditionsToGormQuery(db *gorm.DB, conditions []string, combineType CombineType) *gorm.DB {
+	queryDB := db
+	for _, cond := range conditions {
+		switch combineType {
+		case CombineTypeOr:
+			queryDB = queryDB.Or(cond)
+		case CombineTypeAnd:
+			queryDB = queryDB.Where(cond)
+		}
+	}
+	return queryDB
+}

examples/object_conditions_model.conf

@@ -0,0 +1,14 @@
+[request_definition]
+r = sub, obj, act
+
+[policy_definition]
+p = sub, sub_rule, act
+
+[role_definition]
+g = _, _
+
+[policy_effect]
+e = some(where (p.eft == allow))
+
+[matchers]
+m = g(r.sub, p.sub) && eval(p.sub_rule) && r.act == p.act

examples/object_conditions_policy.csv

@@ -0,0 +1,5 @@
+p, alice, r.obj.price < 25, read
+p, admin, r.obj.category_id = 2, read
+p, bob, r.obj.author = bob, write
+
+g, alice, admin

go.mod

@@ -3,7 +3,7 @@ module github.com/casbin/gorm-adapter/v3
 go 1.20
 
 require (
-	github.com/casbin/casbin/v2 v2.55.1
+	github.com/casbin/casbin/v2 v2.68.0
 	github.com/glebarez/sqlite v1.7.0
 	github.com/go-sql-driver/mysql v1.6.0
 	github.com/lib/pq v1.10.2

go.sum

@@ -7,8 +7,8 @@ github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible h1
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
 github.com/Masterminds/semver/v3 v3.1.1 h1:hLg3sBzpNErnxhQtUy/mmLR2I9foDujNK030IGemrRc=
 github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
-github.com/casbin/casbin/v2 v2.55.1 h1:vaTAHSLkQfielg9UiHdIdvIVK/NAmMjBkDkrOM9iDqI=
-github.com/casbin/casbin/v2 v2.55.1/go.mod h1:vByNa/Fchek0KZUgG5wEsl7iFsiviAYKRtgrQfcJqHg=
+github.com/casbin/casbin/v2 v2.68.0 h1:7L4kwNJJw/pzdSEhl4SkeHz+1JzYn8guO+Q422sxzLM=
+github.com/casbin/casbin/v2 v2.68.0/go.mod h1:vByNa/Fchek0KZUgG5wEsl7iFsiviAYKRtgrQfcJqHg=
 github.com/cockroachdb/apd v1.1.0 h1:3LFP3629v+1aKXU5Q37mxmRxX/pIu1nijXydLShEq5I=
 github.com/cockroachdb/apd v1.1.0/go.mod h1:8Sl8LxpKi29FqWXR16WEFZRNSz3SoPzUzeMeY4+DwBQ=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=