Serializing Models

When returning models in API responses, you often need to exclude sensitive fields or pick specific columns. Use database.Serialize, struct tags, or API Resources for more complex transformations.

database.Serialize

Convert a model to a map, controlling which fields are included:

m, err := database.Serialize(user, database.SerializeOptions{
    Omit: []string{"password", "remember_token"},
})
return c.JSON(200, m)
// {  "id": 1, "name": "Jane", "email": "jane@example.com", "created_at": "..." }

Pick Specific Fields

m, _ := database.Serialize(user, database.SerializeOptions{
    Pick: []string{"id", "name", "email"},
})
// { "id": 1, "name": "Jane", "email": "jane@example.com" }

SerializeOptions

Struct Tags

Permanently hide fields from all JSON output with json:"-":

type User struct {
    database.Model
    Name     string
    Email    string
    Password string `json:"-"`  // never serialized
    APIKey   string `json:"-"`  // never serialized
}

// When using c.JSON(200, user), Password and APIKey are excluded

IsDirty

Check if a model has been modified since loading from the database:

// Load from DB
var user User
db.First(&user, 1)

// Modify
user.Name = "Updated"

// Check if changed
if database.IsDirty(&user) {
    db.Save(&user)
}

API Example

func ListUsers(c *http.Context) error {
    var users []User
    database.Get().Find(&users)

    // Serialize each user with omitted fields
    result := make([]map[string]any, len(users))
    for i, u := range users {
        result[i], _ = database.Serialize(u, database.SerializeOptions{
            Omit: []string{"password", "api_key"},
        })
    }
    return c.JSON(200, result)
}

// For more complex transformations, use API Resources instead