swift - Failable convenience initializer with optional parameters -

i'm looking best way structure class failable convenience initializer optional parameters. current code:

class member: nsobject {      var uid: string     let avatarurl: nsurl     let created: nsdate     let email: string     let name: string     let provider: string      var posts = [post]()     var comments = [comment]()      // initialize member raw data     init(uid: string, avatarurl: nsurl, created: nsdate, email: string, name: string, provider: string){         self.uid = uid         self.avatarurl = avatarurl         self.created = created         self.email = email         self.name = name         self.provider = provider         super.init()     }      convenience init?(snapshot: fdatasnapshot){         if let uid = snapshot.key {             if let avatarurlstring = snapshot.value["avatarurl"] as? string {                 if let avatarurl = nsurl(string: avatarurlstring) {                     if let membercreated = snapshot.value["created"] as? nsdate {                         if let memberemail = snapshot.value["email"] as? string {                             if let membername = snapshot.value["name"] as? string {                                 if let memberprovider = snapshot.value["provider"] as? string {                                                                       self.init(uid: uid, avatarurl: avatarurl, created:membercreated, email: memberemail, name: membername, provider: memberprovider)                                 }                             }                         }                     }                 }             }         }         return nil     } } 

i need either initialize member manually (init) or passing firebase object (convenience init). if of optionals fail within convenience init, i'd fail.

currently, won't build because:

all stored properties of class instance must initialized before returning nil initializer

not sure i'm missing.

any opinions better way approach welcome.

this known issue in failable initializers swift team still working on improving. say, properties must set before returning nil, set them ("" or nsdate() in case). it's bit tedious, necessary.

just clearer, since can little tricky sometimes, here 1 way:

convenience init?(snapshot: fdatasnapshot){     if let uid = snapshot.key {         if let avatarurlstring = snapshot.value["avatarurl"] as? string {             if let avatarurl = nsurl(string: avatarurlstring) {                 if let membercreated = snapshot.value["created"] as? nsdate {                     if let memberemail = snapshot.value["email"] as? string {                         if let membername = snapshot.value["name"] as? string {                             if let memberprovider = snapshot.value["provider"] as? string {                                 self.init(uid: uid, avatarurl: avatarurl, created:membercreated, email: memberemail, name: membername, provider: memberprovider)                                 return                             }                         }                     }                 }             }         }     }      self.init(uid: "", avatarurl: nsurl(), created: nsdate(), email: "", name: "", provider: "")     return nil } 

(in swift 1.2, able stack let's together, make code bit clearer , let use else rather return in middle.)

the key in convenience initializer, must call self.init, if you're going call return nil later. (the swift team knows annoying, there corner cases difficult deal with.)