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State Handling of GoogleApiClient5:25 with Jamie Huson
Now that you have the basic architecture in place you need to fill out our Helper class to make it functional.
Now that we have the basic architecture in place, 0:01 we need to fill out our helper class to make it functional. 0:03 According to the documentation, you should initiate talking to Google Play services 0:06 by calling connect in on start, and disconnect in on stop of your activity. 0:10 We need a way to do this with our helper, so let's add in those methods now. 0:16 We're just gonna go ahead and add in a few public methods. 0:20 This is what our activity's gonna call through too. 0:25 It's gonna call connect. 0:27 And we're simply going to pass this through to our API client. 0:32 And with disconnect we're gonna do the same thing. 0:38 And one thing to think about when we're writing code like this is that 0:41 what happens if Google Play services isn't available, what should we do then? 0:46 Well, we should check that and handle those cases to make sure our code 0:50 doesn't crash, or throw a null pointer exception, or another error. 0:55 So let's go ahead and add in a method, and what this is gonna do is just 0:58 check if Google Play services is possibly available for us to connect to. 1:03 It doesn't guarantee we'll be able to connect, but 1:08 it's just saying is this available on the device at all? 1:10 So let's go ahead and check this. 1:12 It's gonna be a boolean. 1:14 So it'll return back if it's connected or if it's available or 1:15 if it's not available. 1:18 And we're just gonna call it is Play, is Google Play services, or 1:20 PlayServicesAvailable. 1:25 And the great thing is that Google Play Services has 1:30 a utility class built in to help us verify this. 1:33 And the call we're gonna make is GooglePlayServicesUtil. 1:37 So in here, and we're gonna call isPlayServicesAvailable. 1:43 And it needs a context, so we're gonna go ahead and use that activity we stored. 1:48 And this is gonna return back to us an integer about the availability. 1:53 Now what we're gonna do is go ahead and 1:57 switch on that integer and Google Play services has 2:02 also included some constants to know what the result of that availability is. 2:08 So, for one, there's a case stored on the ConnectionResult class and 2:14 that is SUCCESS. 2:19 So, in this case, yeah, Google Play services is available, 2:22 you wanna return true. 2:24 The other cases are cases where a, ab disabled, or 2:27 an update is needed, something like that. 2:32 So, we're gonna handle those cases as well, but we're going to put them all 2:34 under the same case because they're all gonna have the same result. 2:38 We need to figure out a way to resolve that error. 2:42 So, let's go ahead and add in those cases here. 2:44 So there's SERVICE_INVALID, DISABLED, UPDATE_REQUIRED. 2:49 So these three right here, we can all do the same thing with these. 2:54 So let's go ahead and add in all these cases together. 2:57 [BLANK_AUDIO] 3:01 SERVICE_INVALID. 3:09 Okay and what we're gonna do here is now, 3:11 the util has provided an additional method for us. 3:13 And what this is gonna do is, it's gonna display a dialogue to the user. 3:17 And hopefully, the user will be able to resolve this error, and 3:21 we'll be able to connect eventually. 3:26 So, let's go ahead and use GooglePlayServicesUtil, and 3:28 there's something called getErrorDialogue. 3:32 And what we need to do here, 3:37 is pass in the availability code we got back from the other util method. 3:39 And you pass in our activity. 3:44 And then we need to pass in a request code. 3:46 So what this is doing underneath is this is calling though to start activity for 3:48 results. 3:53 And it's displaying this dialogue to the user. 3:54 So it's gonna display another activity to the user. 3:56 And we need to know if that request code comes back, what the result of that was. 3:59 So we need a unique request code here. 4:04 So let's go ahead and define a unique request code in the top of our class. 4:06 And we're gonna define one right here. 4:11 Private static final int REQUEST_CODE. 4:13 And I'm gonna call this one AVAILABILITY. 4:18 And it's gonna give it a unique value here, -101. 4:21 And I have to find another one up here, -100. 4:26 We're gonna use that in a minute. 4:29 And again, these are because we're calling through to start activity for result. 4:31 We need a unique code for every time we call through to that. 4:35 In this case, we're calling it multiple times. 4:39 So that means we need to know when it comes back, which one am I handling? 4:41 So that's why these values are unique. 4:45 We're going to go ahead and do REQUEST_CODE_AVAILABILITY. 4:48 And we have to call show on this, cuz this actually returns back a dialog object. 4:51 So we need to call show otherwise it won't be shown to the user. 4:58 In this case we're gonna return false because we aren't sure that Google Play 5:00 services are available but using this error dialogue we'll go ahead and 5:06 display something to the user and we might come back and connect after all but for 5:12 now we just don't know, and by default we're just gonna return false. 5:16 Now that we've handled those various states, lets take a break. 5:21
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