我有一系列顺序的云工具包调用,以基于先前的获取来获取记录。这些提取中的任何一个都可能失败,然后我必须跳到上一个控制器。由于存在很多提取失败的地方,因此我必须在许多位置将popViewController嵌入到以前的控制器中。我可以避免这种情况,并在可能的情况下仅调用一次popover吗?
func iCloudSaveMeterHubPrivateDbCz() {
self.clOps.iCloudFetchRecord(recordName: locId, databaseScope: CKDatabaseScope.private, customZone: true, completion: { (locationRecord, error) in
guard error == nil else {
self.navigationController!.popViewController(animated: true)
return
}
self.iCloudFetchMeter(withLocationCKRecord: locationRecord!) { records, error in
if (error != nil ) {
if let ckerror = error as? CKError {
self.aErrorHandler.handleCkError(ckerror: ckerror)
}
self.navigationController!.popViewController(animated: true)
}
if let _ = records?.first {
self.clOps.iCloudFetchRecord(recordName: contactId, databaseScope: CKDatabaseScope.private, customZone: true, completion: { (contactRecord, error) in
if let ckerror = error as? CKError {
self.aErrorHandler.handleCkError(ckerror: ckerror)
self.navigationController!.popViewController(animated: true)
}
DispatchQueue.main.async {
if let record = contactRecord {
record.setObject("true" as NSString, forKey:"assignedEEP")
}
}
}
self.navigationController!.popViewController(animated: true)
}
}
})
}
[每当我进入这样的嵌套回调时,我都会尝试合并处理对代码中单个点的响应。在这种情况下,流行的编码员座右铭会有所帮助:“不要重复自己”
这里是通过使主函数具有闭包来合并错误处理和弹出到单个位置的建议:
func iCloudSaveMeter(finished: @escaping (_ success: Bool, _ error: CKError?) -> Void){
self.clOps.iCloudFetchRecord(recordName: locId, databaseScope: CKDatabaseScope.private, customZone: true, completion: { (locationRecord, error) in
if error != nil {
//:::
finished(false, error)
}
self.iCloudFetchMeter(withLocationCKRecord: locationRecord!) { records, error in
if error != nil {
//:::
finished(false, error)
}
if let _ = records?.first {
self.clOps.iCloudFetchRecord(recordName: contactId, databaseScope: CKDatabaseScope.private, customZone: true, completion: { contactRecord, error in
//:::
finished(false, error)
DispatchQueue.main.async {
if let record = contactRecord {
record.setObject("true" as NSString, forKey:"assignedEEP")
}
}
}
}
//:::
finished(true, nil)
}
})
}
//----
//Call it like this
iCloudSaveMeter(){ success, error in
//Pop
if !success{
self.navigationController!.popViewController(animated: true)
}
//Hande error
if let error = error{
self.aErrorHandler.handleCkError(ckerror: error)
}
}