github.com/s7techlab/cckit@v0.10.5/examples/cars/cars.go (about)

     1  // Simple CRUD chaincode for store information about cars
     2  package cars
     3  
     4  import (
     5  	"time"
     6  
     7  	"github.com/s7techlab/cckit/extensions/owner"
     8  	"github.com/s7techlab/cckit/router"
     9  	p "github.com/s7techlab/cckit/router/param"
    10  )
    11  
    12  const CarEntity = `CAR`
    13  const CarRegisteredEvent = `CAR_REGISTERED`
    14  
    15  // CarPayload chaincode method argument
    16  type CarPayload struct {
    17  	Id    string
    18  	Title string
    19  	Owner string
    20  }
    21  
    22  // Car struct for chaincode state
    23  type Car struct {
    24  	Id    string
    25  	Title string
    26  	Owner string
    27  
    28  	UpdatedAt time.Time // set by chaincode method
    29  }
    30  
    31  // Key for car entry in chaincode state
    32  func (c Car) Key() ([]string, error) {
    33  	return []string{CarEntity, c.Id}, nil
    34  }
    35  
    36  func New() *router.Chaincode {
    37  	r := router.New(`cars`) // also initialized logger with "cars" prefix
    38  
    39  	r.Init(invokeInit)
    40  
    41  	r.Group(`car`).
    42  		Query(`List`, queryCars).                                             // chain code method name is carList
    43  		Query(`Get`, queryCar, p.String(`id`)).                               // chain code method name is carGet, method has 1 string argument "id"
    44  		Invoke(`Register`, invokeCarRegister, p.Struct(`car`, &CarPayload{}), // 1 struct argument
    45  			owner.Only) // allow access to method only for chaincode owner (authority)
    46  
    47  	return router.NewChaincode(r)
    48  }
    49  
    50  // ======= Init ==================
    51  func invokeInit(c router.Context) (interface{}, error) {
    52  	return owner.SetFromCreator(c)
    53  }
    54  
    55  // ======= Chaincode methods =====
    56  
    57  // car get info chaincode method handler
    58  func queryCar(c router.Context) (interface{}, error) {
    59  	// get state entry by composite key using CarKeyPrefix and car.Id
    60  	//  and unmarshal from []byte to Car struct
    61  	return c.State().Get(&Car{Id: c.ParamString(`id`)})
    62  }
    63  
    64  // cars car list chaincode method handler
    65  func queryCars(c router.Context) (interface{}, error) {
    66  	return c.State().List(
    67  		CarEntity, // get list of state entries of type CarKeyPrefix
    68  		&Car{})    // unmarshal from []byte and append to []Car slice
    69  }
    70  
    71  // carRegister car register chaincode method handler
    72  func invokeCarRegister(c router.Context) (interface{}, error) {
    73  	// arg name defined in router method definition
    74  	p := c.Param(`car`).(CarPayload)
    75  
    76  	t, _ := c.Time() // tx time
    77  	car := &Car{     // data for chaincode state
    78  		Id:        p.Id,
    79  		Title:     p.Title,
    80  		Owner:     p.Owner,
    81  		UpdatedAt: t,
    82  	}
    83  
    84  	// trigger multiple event
    85  	if err := c.Event().Set(CarRegisteredEvent+`First`, car); err != nil {
    86  		return nil, err
    87  	}
    88  
    89  	if err := c.Event().Set(CarRegisteredEvent, car); err != nil {
    90  		return nil, err
    91  	}
    92  
    93  	return car, // peer.Response payload will be json serialized car data
    94  		//put json serialized data to state
    95  		// create composite key using CarKeyPrefix and car.Id
    96  		c.State().Insert(car)
    97  }