Realm - Add file with initial data to project (iOS

Question

I'm developing an application for iOS using swift and chose Realm as a database solution for it. I wrote default data in AppDelegate using write/add function from realm docs and it works just fine. So after first launch I have a *.realm file with my initial data. In Realm documentation I found a section called "Bundling a Realm with an App", I add my *.realm file to project and to Build Phases as it written.

And I can't understand what I should do next (and part about compressing a *.realm file). I've tried to understand a code from Migration Example but I don't know Obj-C well.

Please give as clear steps as you can to add *.realm file with initial data to swift ios project and load this data to the Realm db with the first launch.

Answer 1

Work in the enterprise space, I need to open a Realm for each application without reusing Realm across all applications so I put this together for Swift 3.0. Add this function to the AppDelegate.

func openRealm()
   {
      let appName = "ApplcationNameGoesHere"
      var rlmConfig = Realm.Configuration()
      let defaultRealmPath = Realm.Configuration.defaultConfiguration.fileURL!
      let appRealmPath = defaultRealmPath.deletingLastPathComponent().appendingPathComponent("\(appName).realm")
      if !FileManager.default.fileExists(atPath: appRealmPath.path) {
     // Use the default directory, but replace the filename with the application name: appName
         rlmConfig.fileURL = rlmConfig.fileURL!.deletingLastPathComponent().appendingPathComponent("\(appName).realm")

     }else
      {
         rlmConfig.fileURL = appRealmPath
      }
      // Set this as the configuration used for the default Realm
      Realm.Configuration.defaultConfiguration = rlmConfig      
   }// open the Realm database for the application

The code above opens or creates a Realm with the file name of "ApplicationNameGoesHere.realm" based on the appName variable in this example.

place

openRealm() before return true in application: didFinishLaunchingWithOptions


func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
      // Override point for customization after application launch.
      openRealm()

      return true

}

call it in another class like this:

let uiRealm = try! Realm()

Answer 2

Updating @pteofil's openRealm function for Swift 2.2/Realm 1.0.2:

func openRealm() {

    let defaultURL =  Realm.Configuration.defaultConfiguration.fileURL!        
    let bundleReamPath = NSBundle.mainBundle().URLForResource("default", withExtension: "realm")


    if !NSFileManager.defaultManager().fileExistsAtPath(defaultURL.path!) {
        do {
        try NSFileManager.defaultManager().copyItemAtURL(bundleReamPath!,  toURL: defaultURL)
         }
        catch {}
        }

}

Answer 3

If you want to open it straight from the bundle location and not bother copying it to the default Realm path, look at the implementation here

Answer 4

And for those that need @pteofil's answer in Objective-c

- (void)openRealm {
    NSString *defaultRealmPath = [RLMRealm defaultRealm].path;
    NSString *bundleRealmPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"default.realm"];
    if(![[NSFileManager defaultManager] fileExistsAtPath:defaultRealmPath]) {
        [[NSFileManager defaultManager] copyItemAtPath:bundleRealmPath toPath:defaultRealmPath error:nil];
    }
}

Answer 5

Implement this function openRealm in AppDelegate and call it in

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { 
    ...
    openRealm() 

    return true
 }

func openRealm() {

    let defaultRealmPath = Realm.defaultPath
    let bundleReamPath = NSBundle.mainBundle().resourcePath?.stringByAppendingPathComponent("default.realm")

    if !NSFileManager.defaultManager().fileExistsAtPath(defaultRealmPath) {
        NSFileManager.defaultManager().copyItemAtPath(bundleReamPath!, toPath: defaultRealmPath, error: nil)
    }
}

It will copy your realm file that you bundled in the app to the default realm path, if it doesn't exist already. After that you use Realm normally like you used before.

There's also the Migration example that you talked about in Swift.

In Swift 3.0.1 you may prefer this:

    let defaultRealmPath = Realm.Configuration.defaultConfiguration.fileURL!
    let bundleRealmPath = Bundle.main.url(forResource: "seeds", withExtension: "realm")

    if !FileManager.default.fileExists(atPath: defaultRealmPath.absoluteString) {
        do {
            try FileManager.default.copyItem(at: bundleRealmPath!, to: defaultRealmPath)
        } catch let error {
            print("error copying seeds: \(error)")
        }
    }

(but please be careful with the optionals)

Answer 6

Swift version 3, courtesy of Kishikawa Katsumi:

let defaultRealmPath = Realm.Configuration.defaultConfiguration.fileURL!
let bundleReamPath = Bundle.main.path(forResource: "default", ofType:"realm")

if !FileManager.default.fileExists(atPath: defaultRealmPath.path) {
do
{
    try FileManager.default.copyItem(atPath: bundleReamPath!, toPath: defaultRealmPath.path)
}
catch let error as NSError {
    // Catch fires here, with an NSError being thrown
    print("error occurred, here are the details:\n \(error)")
}
}