CODEWITHSUNDEEP
iosreachability
bcl
bcl

Reputation: 518

Best approach to doing something once an Internet connection becomes available

I've seen plenty of examples here on how to check an internet connection is available but nobody seems to explain the best practice way of doing something once/ if it becomes available.

I'm using Tony Million's Reachability class and have a 'connection available' block that sets a boolean (Online) to true once the connection is available. The Reachability class is initialized in my app delegate didFinishLaunchingWithOptions but by the time my code checks the status of Online Reachability still hasn't finished figuring out if there's a connection, and so my app always sees itself as being offline when it first starts.

Now, I could put my connection-requiring code into the 'connection available' block but there's more than one place my app needs the internet so that's obviously not flexible enough for my needs.

The 'best' idea I had so far is to populate an array with methods that need the internet to do their thing and then have Reachability execute whatever is in that array once it knows there's a connection... but am I over-complicating matters here? Is there a better way of going about this?

Upvotes: 1

Views: 393

Answers (1)

Florian
Florian

Reputation: 5405

This is roughly based on your "best idea". Tony Million's Reachability also posts notifications via NSNotificationCenter when the internet connection changes. All your classes that need to do something when an internet connection becomes available, should register for this notification.

On the GitHub page there is an example for that: https://github.com/tonymillion/Reachability#another-simple-example

You would initialize the Reachability class in your app delegate, like you do right now. And then your other classes register for the kReachabilityChangedNotification notification with the NSNotificationCenter in their initializer. They also have to deregister from the NSNotificationCenter in their dealloc method.

Here is some code you can use as starting point:

- (void)registerForReachabilityNotification
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(reachabilityChanged:)
                                                 name:kReachabilityChangedNotification
                                               object:nil];
}

- (void)deregisterFromNotifications
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)reachabilityChanged:(NSNotification *)notification
{
    Reachability *reachability = notification.object;
    switch ([reachability currentReachabilityStatus]) {
        case NotReachable:
            // No connection
            break;
        case ReachableViaWiFi:
        case ReachableViaWWAN:
            // Connection available
            break;
    }
}

Upvotes: 2

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