Add option WithNullableNameStrategy to use custom nullable column type formater

Author: pivaldi

config.go

@@ -54,8 +54,9 @@ type Config struct {
 	modelNameNS func(tableName string) (modelName string)
 	fileNameNS  func(tableName string) (fileName string)
 
-	dataTypeMap    map[string]func(columnType gorm.ColumnType) (dataType string)
-	fieldJSONTagNS func(columnName string) (tagContent string)
+	dataTypeMap     map[string]func(columnType gorm.ColumnType) (dataType string)
+	fieldJSONTagNS  func(columnName string) (tagContent string)
+	fieldNullableNS func(columnType string) (nullableColumnType string)
 
 	modelOpts []ModelOpt
 }
@@ -103,6 +104,11 @@ func (cfg *Config) WithJSONTagNameStrategy(ns func(columnName string) (tagConten
 	cfg.fieldJSONTagNS = ns
 }
 
+// WithNullableNameStrategy specify nullable type name strategy
+func (cfg *Config) WithNullableNameStrategy(ns func(columnType string) (nullableColumnType string)) {
+	cfg.fieldNullableNS = ns
+}
+
 // WithImportPkgPath specify import package path
 func (cfg *Config) WithImportPkgPath(paths ...string) {
 	for i, path := range paths {

generator.go

@@ -183,7 +183,8 @@ func (g *Generator) genModelConfig(tableName string, modelName string, modelOpts
 			FieldWithIndexTag: g.FieldWithIndexTag,
 			FieldWithTypeTag:  g.FieldWithTypeTag,
 
-			FieldJSONTagNS: g.fieldJSONTagNS,
+			FieldNullableNS: g.fieldNullableNS,
+			FieldJSONTagNS:  g.fieldJSONTagNS,
 		},
 	}
 }

internal/generate/generate.go

@@ -20,6 +20,7 @@ func getFields(db *gorm.DB, conf *model.Config, columns []*model.Column) (fields
 	for _, col := range columns {
 		col.SetDataTypeMap(conf.DataTypeMap)
 		col.WithNS(conf.FieldJSONTagNS)
+		col.WithNullableFieldTypeNS(conf.FieldNullableNS)
 
 		m := col.ToField(conf.FieldNullable, conf.FieldCoverable, conf.FieldSignable)
 

internal/model/config.go

@@ -35,17 +35,18 @@ type NameStrategy struct {
 type FieldConfig struct {
 	DataTypeMap map[string]func(columnType gorm.ColumnType) (dataType string)
 
-	FieldNullable     bool // generate pointer when field is nullable
+	FieldNullable     bool // Use FieldNullableFormater when field is nullable
 	FieldCoverable    bool // generate pointer when field has default value
 	FieldSignable     bool // detect integer field's unsigned type, adjust generated data type
 	FieldWithIndexTag bool // generate with gorm index tag
 	FieldWithTypeTag  bool // generate with gorm column type tag
 
 	FieldJSONTagNS func(columnName string) string
-
-	ModifyOpts []FieldOption
-	FilterOpts []FieldOption
-	CreateOpts []FieldOption
+	// Formater used when field is nullable and FieldNullable is true. Default : generate pointer
+	FieldNullableNS func(columnType string) string
+	ModifyOpts      []FieldOption
+	FilterOpts      []FieldOption
+	CreateOpts      []FieldOption
 }
 
 // MethodConfig method configuration

internal/model/tbl_column.go

@@ -12,11 +12,12 @@ import (
 // Column table column's info
 type Column struct {
 	gorm.ColumnType
-	TableName   string                                                        `gorm:"column:TABLE_NAME"`
-	Indexes     []*Index                                                      `gorm:"-"`
-	UseScanType bool                                                          `gorm:"-"`
-	dataTypeMap map[string]func(columnType gorm.ColumnType) (dataType string) `gorm:"-"`
-	jsonTagNS   func(columnName string) string                                `gorm:"-"`
+	TableName            string                                                        `gorm:"column:TABLE_NAME"`
+	Indexes              []*Index                                                      `gorm:"-"`
+	UseScanType          bool                                                          `gorm:"-"`
+	dataTypeMap          map[string]func(columnType gorm.ColumnType) (dataType string) `gorm:"-"`
+	jsonTagNS            func(columnName string) string                                `gorm:"-"`
+	nullableTypeFormater func(columnType string) string                                `gorm:"-"`
 }
 
 // SetDataTypeMap set data type map
@@ -43,6 +44,15 @@ func (c *Column) WithNS(jsonTagNS func(columnName string) string) {
 	}
 }
 
+// WithNullableFieldTypeNS with nullable type name strategy
+// If nil use pointer, the default
+func (c *Column) WithNullableFieldTypeNS(formater func(columnType string) string) {
+	c.nullableTypeFormater = formater
+	if c.nullableTypeFormater == nil {
+		c.nullableTypeFormater = func(fType string) string { return "*" + fType }
+	}
+}
+
 // ToField convert to field
 func (c *Column) ToField(nullable, coverable, signable bool) *Field {
 	fieldType := c.GetDataType()
@@ -56,7 +66,7 @@ func (c *Column) ToField(nullable, coverable, signable bool) *Field {
 		fieldType = "*" + fieldType
 	case nullable && !strings.HasPrefix(fieldType, "*"):
 		if n, ok := c.Nullable(); ok && n {
-			fieldType = "*" + fieldType
+			fieldType = c.nullableTypeFormater(fieldType)
 		}
 	}