Swift FMDB Code Explanation - ios

Question

I am a beginner to Swift and FMDB, I got the code below from resources in the internet, and tried my best to understand the code. I have put comments below statements stating what I think it is doing. The ones with question marks I do not understand.
class ViewController: UIViewController {
#IBOutlet weak var name: UITextField!
#IBOutlet weak var specialty: UITextField!
//Defines name and specialty as contents of text fields
var dbpath = String()
//defines the database path
func getPath(fileName: String) -> String {
let documentsURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
//finds document and returns an array of paths
let fileURL = documentsURL.URLByAppendingPathComponent(fileName)
print(fileName)
//finds path to fileName with URLByAppendingPathComponent
print("File Path Is : \(fileURL)")
return fileURL.path!
//returns the fileURL in path format?????
}
//Button "Add Shop" definition
override func viewDidLoad() {
super.viewDidLoad()
let dirPaths =
NSSearchPathForDirectoriesInDomains(.DocumentDirectory,
.UserDomainMask, true)
//creates search paths for directories, then ?????
let docsDir = dirPaths[0]
let dbPath: String = getPath("shopdata.db")
//assigns string "shopdata.db" to dbPath
let fileManager = NSFileManager.defaultManager()
//easier access for NSFileManager, returns shared file for the process when called
if !fileManager.fileExistsAtPath(dbPath as String) {
//if there is already a database, do the following
let contactDB = FMDatabase(path: dbPath as String)
//contact database with path identified in function getPath
if contactDB == nil {
print("Error: \(contactDB.lastErrorMessage())")
//If there is no database
}
if contactDB.open() {
let sql_stmt = "CREATE TABLE IF NOT EXISTS CONTACTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, SPECIALTY TEXT, NAME TEXT)"
if !contactDB.executeStatements(sql_stmt)
//executes a create table statement as defined above
{
print("Error: \(contactDB.lastErrorMessage())")
//if cannot execute statement, display error from fmdb
}
contactDB.close()
//close connection
} else {
print("Error: \(contactDB.lastErrorMessage())")
//if contact cannot be made, display error from fmdb
}
}
}
#IBAction func addShop(sender: AnyObject) {
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

Answer 1

This Function will get the file path of the give fileName from DocumentDirectory and return it back.
func getPath(fileName: String) -> String {
let documentsURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
//finds document and returns an array of paths
let fileURL = documentsURL.URLByAppendingPathComponent(fileName)
print(fileName)
//finds path to fileName with URLByAppendingPathComponent
print("File Path Is : \(fileURL)")
return fileURL.path!
//returns the fileURL in path format?????
}
And these line of code is not needed in here at all. This code also get the file path from DocumentDirectory of the application. Which is done in the getPath: function.
let dirPaths =
NSSearchPathForDirectoriesInDomains(.DocumentDirectory,
.UserDomainMask, true)
//creates search paths for directories, then ?????
let docsDir = dirPaths[0]
DocumentDirectory is where the application save the database.
Sorry for bad English. Hope it helps :)