Having to agree to T&Cs on first run in Swift - ios

I was wondering if it would be possible to programmatically make users agree to the Terms of Service I have for my application, but for them only to have to agree to it the first time they run the app straight after downloading it, as Apple requires Terms and Conditions for a social networking type application. Any help would be much appreciated as it will be one of the deciding factors on whether my app makes it to the app store or not.

Here a simple solution:
Put your to-be-called method in your delegate's application:didFinishLaunchingWithOptions, which means the T&C are shown to the user as soon as he starts the application. Then for the "once-in-a-lifetime" you could simple store a value in NSUserDefault(e.g. a string "alreadySent") at the end your custom method, which will persist over time as soon as the user doesn't delete application & data.
So the flow of event could be
App launch
Check: is the NSUserDefault value "alreadySent"?
No: Ok call method and show T&C
Yes: skip
This is a simple method which gives you a one-shot way to show the user what you want.
(Just google if you don't know how the NSUserDefault works, it's straightforward)

Related

Disable multi-tab browsing for single session/user

[Disclaimer: I'm not sure if this kind of question is accepted here as it is about a piece of software deployed already. Rest assured I didn't drop any confidential information. Also do tell me if I violated any rules in SO by posting this so I can take it down immediately]
I have a working Learning Management System web application and I recently received a bug report about a button not showing. After investigating, I have proved that the user was not using the web app as intended. When taking an exam, he was opening multiple tabs to exploit the feature that informs him whether the answer was correct or not. He then will use this information to eliminate the wrong answers and submit all the right answers in another tab/window.
I'm using Rails 4.2. Is there a way to prevent multi-tab browsing? I'm thinking like if a user is signed in and he attempted to open a new tab of the webapp, he should see something like "Please use one tab" and all the features/hyperlinks/buttons are disabled.
Here's a screenshot of how I proved he was using multiple tabs. Notice that there are multiple logs of the same attempt # because the current implementation allows saving a study session and resuming later (this is the part that's exploited). The opening of multiple tabs searches for the most recent attempt session and continues from there. This is also the reason why most of the sessions don't have a duration value -- the user only finishes a study session for one tab (by clicking a button that ends the study session). The system cannot compute for the duration because the other sessions don't have an end timestamp.
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This is what a single-tab user looks like:
This is more of an application misuse issue more than a bug.
You should add protection not only from multi tab, but for multi browsers aw well, so it can't be purely FrontEnd check.
One of the solutions could be using ActionCable to check if a user has an active connection already and then act accordingly.
Another, for example, generate a GUID in JS and pass it with every answer. If its different from previous answer, it means user opened a new window.
But of course the solution would depend on your current architecture, without knowing how do you currently organise client-server communication it's hard to give exact and optimal solution.
I found an answer here. I just placed this js in the application view to prevent any extra instance of the website.
Thanks for everyone who pitched in.

Local storage on Rails

I've built a Rails app, basically a CRUD app for memos/notes.
A notes title must be unique. If a user enters a name already taken a warning message is shown prompting them to chose another.
My question is how to make this latency for this feedback as close to zero as possible. When creating a note little UX speed bumps like this will get annoying for user quickly.
Of course the main bottleneck is the network. Inspired by Meteor (and mini-mongo) I was thinking some kind of local storage could be a solution?
I.E. When app first loads, send ALL JSON to the client with ALL note titles. The app (front end is Angular JS) could check LocalStorage (or App Cache, Web SQL?) instead of incurring a network round trip. The feedback would be instant.
I've used LocalStorage in the past to augment an app, but in the scenario it'd really seriously depend on it. I'm not sure how confident I'd be building on something that user might not have. Also as the number of user Notes/Memos I have doubts how feasible it is to send a JSON object down the wire with ALL the note titles. That might get pretty big. On the other hand MeteorJS seems to do this with no probs.
Has anyone done something similar or have any pointers? Thanks!
I don't know how Meteor works here, but you're right that storing all note titles in localStorage is not a good idea. Actually, you don't need localStorage here, you can just put it in a JS array, because you need this data only once (when checking new note title).
I think, there could be 2 possible solutions:
You can change your business requirements and allow non-unique title. Is there really a necessity for titles to be unique?
You can verify note title when user submits form. In this case you can provide suggestions for users, so they not spend time guessing vacant title.
Or, if titles must be unique only within a user (two users can have same title for their notes), you can really load all note titles in JS array and check uniqueness while users types in a title.
Or you can send an AJAX request checking title uniqueness as soon as user finished typing the title. In this case you can win some seconds.
Or you can send an AJAX request as soon as user typed in 3 symbols. The request will return all titles that begin with these 3 symbols, so you don't need to load all the titles.

Store User Token, If Invalid token - present Login page,

Learning iOS Swift programming and like to know how to implement user login process ?
The backend-iOS mechanism is this :
User login with email and Password,
The Server returns user token and user id
In subsequent requests, user token and user id is sent to fetch data/work with the App.
I have doubt in iOS implementation.
Will be storing User token and User id in Core Data. Will there be
any slowness if I get the user token on every screen from Core
Data?
If the login token expires or is invalid on any screen, how to fall back to login page? Should I check the JSON output and have code "present login VC" on every screen? Any streamlined way to have abstract the code to a swift or cocoa touch file?
Actually, there are many approaches. It's all depends on you, how you will manage it. I can point you two examples, how I manage it by myself.
Using NSOperation.
There was an awesome session on WWDC 2015, about advanced NSOperations. Here it is.
Basically, you create a subclass of NSOperaton and make other operations depend on it. In your case, you will have operation of user login, and all other operations will depend on user login (of course only ones, who needs it). If it succeed, then operation will execute. In user login operation, you will check, if user already logged in, and you have a token, if not, present logging screen.
There is also awesome library called Operations, based on that WWDC talk. Here it is.
Using PromiseKit.
Here is another one, using PromiseKit. It is not really much difference from operations, but, in my opinion, a little simpler. You create Promise that ensures that you did login. It is very simple to make a chain of promises, so you promise a user login and chain anything else from it. If login succeed, chain of promises continues executing.
It's all based on another awesome library, PromiseKit. Here it is
It is very powerful and very simple to use, once you understand the thing. It is very well documented, and has a bunch of tutorials here.
There are many other approaches, so you can choose any of it, and combine one with other however you like.
Asking on your first question, you make it asynchronous, so it is not so much matter about slowness of CoreData as you make a web request.
1 - well, yes, a bit. But I doubt you will notice any lag or anything: CoreData is really fast and it won't take any significant amount of time to fetch just one object. Alternatively, your CoreData object that holds this data (let's call it User) can be a property of your subclass of UIApplicationDelegate (let's call it MyAppDelegate). You will fetch this User in
- application:didFinishLaunchingWithOptions:, and update it on login/logout/expire/etc. In such way you can access it from everywhere, and you don't need to fetch it from CoreData anytime you need it.
Also, instead of CoreData you can use iOS Keychain. (Here is tutorial that might help with this).
2 - again, you can use MyAppDelegate. For example you can add method to it, that will save current navigation state, and change root controller of UIWindow to your LoginViewController. Or it will present LoginViewController on top of current controller. After successful login you will return navigation stack to previous state.
Also you can move this code to some kind of NavigationController - class that will handle this situation. It will have something like
func checkToken(Dictionary response, UIViewController currentController) -> Bool. If token is valid, it just returns true, and if not, it returns false and handles navigation to LoginViewController, and after login - back to currentController. This NavigationController can be property of MyAppDelegate, it can be singleton, created every time you need it, or you can pass it along to every UIViewController that you show.

Creating CloudKit records on scheduled days

I'm working on an app right now that lets the user create new records on a recurring basis, and lets the schedule how many days in advance they want to create those records. This will almost always take place at a time when the app is not running, so I'm exploring my options for getting the app to be woken up to create the objects. As far as I see it there are four options, one of which is probably not really an option, since I'm trying to use only CloudKit and avoid creating a server-side component.
Option 1:
Use Background fetch to periodically refresh the records and check to see if anything is changed. In this instance I would probably have some kind of CloudKit record that represented the recurrence, in addition to the record type that needs to be created. Then I can just check the recurrence object and create a new record if needed
Option 2:
Schedule a local notification when the user schedules the recurrence. I thought this was going to work, but as far as I can tell, the app will not actually be launched even if it's a silent notification, unlike remote notifications.
Option 3:
Write some code locally that will check a data structure whenever the app is launched to check to see if any new records need to be created.
Option 4:
Create a server application that will create the records for me. Like I said, not really something that I want to do, even if it's the "best" option usually.
With option 1 you can not be certain that your app is running.
Option 2 won't work. As you said the app won't be activated. Or the notification must nog be silent and the user has to select to open the app.
Option 3 is much better than 1 and 2 if you don't mind that it could happen that the records won't be created for a long time if the user never opens up your app.
Option 4 is the best option for this. you will have full control over when to add what.
But... Do you already know in front what data to add? Then why are you adding that data? Can't you just calculate it and assume it's there? Maybe even based on a settings record or so?

iOS Cross Cutting Concerns

I have a Swift application i'm working on that allows a user to save various settings about their profile. Throughout my code, there are times where knowing these settings/preferences are important for the application's business logic. One of them is where the user works (their job, (which is a row in a sqllite database that has an ID as a primary key). The user is allowed to select one (and only one) in the app at any given time. Think of it like a profile - they can work many jobs, but only have one selected.
The following are scenarios where knowing the workplaceid profile is important:
In my sqllite database, retrieving work/shift information based upon the currently selected work ID(so not the ID from the database, but the ID they currently have selected). I'm passing this into my query.
In an NSDate extension function, when I go to determine some things about their starting date, I need to retrieve their currently selected profile, and use that for the calculation.
Within a particular view model when I want to show/hide certain fields.
On an alert view to show something related to their current workplace.
Now I think the quick and dirty way to do this is simply create a wrapper class to your nsuserdefaults in a utility class. Sure, all your info is stored in sqllite, but your currently selected app preferences are in nsuserdefaults since I can change this around (and it will change). This would parallel my other cross-cutting concerns such as logging/error handling, where I could use similar utility classes for all my work.
The fact that I might call this helper/utility class from every single layer of my application seems like a typical red flag you wouldn't do. Whether it's logging, or a user service to get information.
I'm curious to know what other people are doing in scenarios like this. When you need nsuserdefaults from all over your app, is the answer "eh who cares, just make a utility class and call it wherever you need it" ? Or is there a best practice others have followed with well-designed iOS apps? I know AOP is something folks tend to recommend. Does that have a place in iOS?
Thanks so much stackoverflow :)
The user is allowed to select one (and only one) in the app at any given time.
This tells me you want to create a singleton class. Every time you want to change the profile, you hit the singleton class and set it. That class encapsulates all the logic to get/set whatever you need, and the accessor functions. That's what I've been doing in my ObjC code for many years, and it has served me well. It's extremely easy to debug, and the rest of the code needs to know nothing about profile management (unless it's the UI part where you choose a profile).

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