GetBSON, SetBSON not called

[Darko Luketic]

package main

import (
    "fmt"
    "labix.org/v2/mgo"
    "labix.org/v2/mgo/bson"
)

const (
    DBHOST = "localhost"
    DBNAME = "test5"
)

var (
    mgoSession  *mgo.Session
    userDB      *mgo.Database
    userR       *userRepository = new(userRepository)
    communityDB *mgo.Database
    communityR  *communityRepository = new(communityRepository)
)

type (
    User struct {
        Id       bson.ObjectId `bson:"_id,omitempty" json:"id"`
        Email    string        `json:"email"`
        Password string        `json:"password"`
    }

    Community struct {
        Id    bson.ObjectId `bson:"_id,omitempty" json:"id"`
        Name  string        `json:"name"`
        Owner *User         `json:"owner"`
    }

    communityRepository struct {
        Collection *mgo.Collection
    }

    userRepository struct {
        Collection *mgo.Collection
    }
)

func main() {
    var (
        err error
    )

    // Connect to Mongo
    mgoSession, err = mgo.Dial(DBHOST)
    if err != nil {
        panic(err)
    }
    defer mgoSession.Close()

    userDB = mgoSession.DB(DBNAME)
    userR.Collection = userDB.C("users")
    communityDB = mgoSession.DB(DBNAME)
    communityR.Collection = communityDB.C("communities")

    u := new(User)
    u.Id = bson.NewObjectIdWithTime(bson.Now())
    u.Email = "darko"
    u.Password = "pass"
    userR.Create(u)

    u1, err := userR.FindOneByEmail("darko")

    c := new(Community)
    c.Id = bson.NewObjectId()
    c.Name = "commy"
    c.Owner = u1
    communityR.Create(c)

}

func (r userRepository) Create(user *User) (err error) {
    if user.Id.Hex() == "" {
        user.Id = bson.NewObjectId()
    }
    _, err = r.Collection.UpsertId(user.Id, user)
    return
}

func (r userRepository) FindOneByEmail(email string) (result *User, err error) {
    result = new(User)
    err = r.Collection.Find(bson.M{"email": email}).One(result)
    return
}

func (r communityRepository) Create(community *Community) (err error) {
    if community.Id.Hex() == "" {
        community.Id = bson.NewObjectId()
    }
    _, err = r.Collection.UpsertId(community.Id, community)
    return
}

func (u *User) GetBSON(raw bson.Raw) error {
    fmt.Printf("raw:%s\n", raw)
    return raw.Unmarshal(u)
}

func (u *User) SetBSON() (interface{}, error) {
    fmt.Printf("set:%s\n", u)
    return u.Id.Hex(), nil
}

########

There is no output
It should output at least either raw: or set:

[Gustavo Niemeyer]

The methods must have the exact interface defined in the
documentation, otherwise they're not considered relevant:

http://labix.org/v2/mgo/bson#Getter
http://labix.org/v2/mgo/bson#Setter

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--

gustavo @ http://niemeyer.net

[Darko Luketic]

Oh god I'm retarded
Thanks and sorry for bothering you

[Matt Siegel]

Another reason for SetBSON not being called: unmarshaling into the wrong type :)

My experience was:

I used GetBSON to marshal a [2]float64 array into a GeoJSON Point (which is a struct) for storage and queries... Conversion worked great in that direction.  But when I tried to load it back in, the data was silently sent into a black hole and I got zeroes instead.  No errors returned, just zeroes in the fields, simply due to array/struct being incompatible for unmarshaling.

The other symptom was SetBSON not being called.

So don't do what I did! :)  I'm switching the array to a struct.

[Gustavo Niemeyer]

You can use a slice or an array too, but you'll need to get a pointer to the
slice, in the same way you get a pointer to the struct, otherwise you'll
modify the copy that the function gets instead of the original value
pointed to by the value address.

Makes sense?

[Matt Siegel]

That makes sense, thanks Gustavo.  Using a struct worked out well in my case, but I'm glad to hear slices are also possible.

My compliments on your excellent library! :)