How to Store and Retrieve User Settings from SUSI Server in SUSI iOS

Any user using the SUSI iOS client can set preferences like enabling or disabling the hot word recognition or enabling input from the microphone. These settings need to be stored, in order to be used across all platforms such as web, Android or iOS. Now, in order to store these settings and maintain a synchronization between all the clients, we make use of the SUSI server. The server provides an endpoint to retrieve these settings when the user logs in.

First, we will focus on storing settings on the server followed by retrieving settings from the server. The endpoint to store settings is as follows:

http://api.susi.ai/aaa/changeUserSettings.json?key=key&value=value&access_token=ACCESS_TOKEN

This takes the key value pair for storing a settings and an access token to identify the user as parameters in the GET request. Let’s start by creating the method that takes input the params, calls the API to store settings and returns a status specifying if the executed successfully or not.

 let url = getApiUrl(UserDefaults.standard.object(forKey: ControllerConstants.UserDefaultsKeys.ipAddress) as! String, Methods.UserSettings)

        _ = makeRequest(url, .get, [:], parameters: params, completion: { (results, message) in
            if let _ = message {
                completion(false, ResponseMessages.ServerError)
            } else if let results = results {
                guard let response = results as? [String : AnyObject] else {
                    completion(false, ResponseMessages.ServerError)
                    return
                }
                if let accepted = response[ControllerConstants.accepted] as? Bool, let message = response[Client.UserKeys.Message] as? String {
                    if accepted {
                        completion(true, message)
                        return
                    }
                    completion(false, message)
                    return
                }
            }
        })

Let’s understand this function line by line. First we generate the URL by supplying the server address and the method. Then, we pass the URL and the params in the `makeRequest` method which has a completion handler returning a results object and an error object. Inside the completion handler, check for any error, if it exists mark the request completed with an error else check for the results object to be a dictionary and a key `accepted`, if this key is `true` our request executed successfully and we mark the request to be executed successfully and finally return the method. After making this method, it needs to be called in the view controller, we do so by the following code.

Client.sharedInstance.changeUserSettings(params) { (_, message) in
  DispatchQueue.global().async {
    self.view.makeToast(message)
  }
}

The code above takes input params containing the user token and key-value pair for the setting that needs to be stored. This request runs on a background thread and displays a toast message with the result of the request.

Now that the settings have been stored on the server, we need to retrieve these settings every time the user logs in the app. Below is the endpoint for the same:

http://api.susi.ai/aaa/listUserSettings.json?access_token=ACCESS_TOKEN

This endpoint accepts the user token which is generated when the user logs in which is used to uniquely identify the user and his/her settings are returned. Let’s create the method that would call this endpoint and parse and save the settings data in the iOS app’s User Defaults.

if let _ = message {
  completion(false, ResponseMessages.ServerError)
} else if let results = results {
  guard let response = results as? [String : AnyObject] else {
    completion(false, ResponseMessages.ServerError)
    return
  }
  guard let settings = 
response[ControllerConstants.Settings.settings.lowercased()] as? [String:String] else {
    completion(false, ResponseMessages.ServerError)
    return
  }
  for (key, value) in settings {
    if value.toBool() != nil {
      UserDefaults.standard.set(value.toBool()!, forKey: key)
    } else {
      UserDefaults.standard.set(value, forKey: key)
    }
  }
  completion(true, response[Client.UserKeys.Message] as? String ?? "error")
}

Here, the creation of the URL is same as we created above the only difference being the method passed. We parse the settings key value into a dictionary followed by a loop which loop’s through all the keys and stores the value in the User Defaults for that key. We simply call this method just after user log in as follows:

Client.sharedInstance.fetchUserSettings(params as [String : AnyObject]) { (success, message) in
  DispatchQueue.global().async {
    print("User settings fetch status: \(success) : \(message)")
  }
}

That’s all for this tutorial where we learned how to store and retrieve settings on the SUSI Server.

References

How can you add a bug?

It’s very simple to start testing, You don’t need any special experience in testing area.To start testing in Open Event project you need to open our web application http://open-event.herokuapp.com/ and you can start.Isn’t it easy? So You should focus on finding as many bugs as possible to provide your users with perfectly working software. If you find a bug you need to describe many details

How can you report a bug to Open Event?

Go to Github page issues, click new issue(green button).

Screen Shot 2016-07-01 at 21.03.45.png

Our Requirements:

Good description – If you found a bug you have to reproduce it, so you have nice background to describe it very well. It’s important because, good issue’s description saves developers time. They don’t need to ask announcer about details of bug. The best description which tester can add is how developer can simply achieve a bug step by step.

Logs – description is sometimes not enough so you need to attach logs which are generated from our server(It’s nice if you have access, if you don’t have ask me)

Pictures – it’s helpful, because we can quickly find where bug is located

Labels – You need to assign Screen Shot 2016-07-01 at 21.26.17.png label to issue

That’s all!

 

Open-Event Permissions System and integrating it with decorators

All the large scale applications require a permissions system. Thus we also implemented a permissions system in our open-event organization server. It consists of certain pre-decided roles:

  1. Super-Admin
  2. Admin
  3. Organizer
  4. Co organizer
  5. Track organizer
  6. Anonymous user

Now we had to decide the permissions which each role would have. Hence we created a documentation regarding what URLs can be accessed by each role. We developed a list of services which the roles could use their permissions to access:

  1. Tracks
  2. Microlocations
  3. Speakers
  4. Sessions
  5. Sponsors

Thus the final step was to implement the permissions system to the appropriate views or URLs. Here comes the power of Flask decorators . I created a individual decorators @is_organizer, @is_admin, @is_super_admin etc… to check the respective roles. I created one main decorator @can_access to see whether the role can access the particular URL or view function

decorator

So in the above decorator I have simply take in the url and check whether it has ‘create’, ‘edit’ or ‘delete’ words in it. Depending on that the control goes in the particular IF statement. Now once it is decided what operation is being performed it checks what service is being accessed by the user. For example: if the operation is edit then it will check whether the service being edited is an event, session, sponsor etc…

Similar checks are performed by each operation. A check is performed of the request.url to see whether the string for that service is present in it. After it knows what service is being accessed its just a matter of using the CRUD functions of user table to check if the role accessing the resource has the requested permission using the functions:

  1. user.can_create()
  2. user.can_read()
  3. user.can_update()
  4. user.can_delete()

After this its just a matter of adding the decorator to each of the view functions and the system is implemented.  🙂