+
+
\ No newline at end of file
diff --git a/README.md b/README.md
index f5ddabf0..0f796a1a 100644
--- a/README.md
+++ b/README.md
@@ -1,19 +1,45 @@
Learning RxJava for Android by example
==============
-This is a repository with real-world useful examples of using RxJava with Android. [It usually will be in a constant state of "Work in Progress" (WIP)](http://nerds.weddingpartyapp.com/tech/2014/09/15/learning-rxjava-with-android-by-example/).
+This is a repository with real-world useful examples of using RxJava with Android. [It usually will be in a constant state of "Work in Progress" (WIP)](https://kau.sh/blog/learning-rxjava-with-android-by-example/).
-## Examples:
+I've also been giving talks about Learning Rx using many of the examples listed in this repo.
+
+* [Learning RxJava For Android by Example : Part 1](https://www.youtube.com/watch?v=k3D0cWyNno4) \[[slides](https://speakerdeck.com/kaushikgopal/learning-rxjava-for-android-by-example)\] (SF Android Meetup 2015)
+* [Learning Rx by Example : Part 2](https://vimeo.com/190922794) \[[slides](https://speakerdeck.com/kaushikgopal/learning-rx-by-example-2)\] (Øredev 2016)
-### Concurrency using schedulers
+## Examples:
-A common requirement is to offload lengthy heavy I/O intensive operationsacc to a background thread (non-UI thread) and feed the results back to the UI/main thread, on completion. This is a demo of how long-running operations can be offloaded to a background thread. After the operation is done, we resume back on the main thread. All using RxJava! Think of this as a replacement to AsyncTasks.
+1. [Background work & concurrency (using Schedulers)](#1-background-work--concurrency-using-schedulers)
+2. [Accumulate calls (using buffer)](#2-accumulate-calls-using-buffer)
+3. [Instant/Auto searching text listeners (using Subjects & debounce)](#3-instantauto-searching-text-listeners-using-subjects--debounce)
+4. [Networking with Retrofit & RxJava (using zip, flatmap)](#4-networking-with-retrofit--rxjava-using-zip-flatmap)
+5. [Two-way data binding for TextViews (using PublishSubject)](#5-two-way-data-binding-for-textviews-using-publishsubject)
+6. [Simple and Advanced polling (using interval and repeatWhen)](#6-simple-and-advanced-polling-using-interval-and-repeatwhen)
+7. [Simple and Advanced exponential backoff (using delay and retryWhen)](#7-simple-and-advanced-exponential-backoff-using-delay-and-retrywhen)
+8. [Form validation (using combineLatest)](#8-form-validation-using-combinelatest)
+9. [Pseudo caching : retrieve data first from a cache, then a network call (using concat, concatEager, merge or publish)](#9-pseudo-caching--retrieve-data-first-from-a-cache-then-a-network-call-using-concat-concateager-merge-or-publish)
+10. [Simple timing demos (using timer, interval or delay)](#10-simple-timing-demos-using-timer-interval-and-delay)
+11. [RxBus : event bus using RxJava (using RxRelay (never terminating Subjects) and debouncedBuffer)](#11-rxbus--event-bus-using-rxjava-using-rxrelay-never-terminating-subjects-and-debouncedbuffer)
+12. [Persist data on Activity rotations (using Subjects and retained Fragments)](#12-persist-data-on-activity-rotations-using-subjects-and-retained-fragments)
+13. [Networking with Volley](#13-networking-with-volley)
+14. [Pagination with Rx (using Subjects)](#14-pagination-with-rx-using-subjects)
+15. [Orchestrating Observable: make parallel network calls, then combine the result into a single data point (using flatmap & zip)](#15-orchestrating-observable-make-parallel-network-calls-then-combine-the-result-into-a-single-data-point-using-flatmap--zip)
+16. [Simple Timeout example (using timeout)](#16-simple-timeout-example-using-timeout)
+17. [Setup and teardown resources (using `using`)](#17-setup-and-teardown-resources-using-using)
+18. [Multicast playground](#18-multicast-playground)
+
+## Description
+
+### 1. Background work & concurrency (using Schedulers)
+
+A common requirement is to offload lengthy heavy I/O intensive operations to a background thread (non-UI thread) and feed the results back to the UI/main thread, on completion. This is a demo of how long-running operations can be offloaded to a background thread. After the operation is done, we resume back on the main thread. All using RxJava! Think of this as a replacement to AsyncTasks.
The long operation is simulated by a blocking Thread.sleep call (since this is done in a background thread, our UI is never interrupted).
To really see this example shine. Hit the button multiple times and see how the button click (which is a UI operation) is never blocked because the long operation only runs in the background.
-### Accumulate calls (buffer)
+### 2. Accumulate calls (using buffer)
This is a demo of how events can be accumulated using the "buffer" operation.
@@ -23,9 +49,9 @@ If you hit the button once, you'll get a message saying the button was hit once.
Note:
-If you're looking for a more foolproof solution that accumulates "continuous" taps vs just the number of taps within a time span, look at the [EventBus Demo](https://github.com/kaushikgopal/Android-RxJava/blob/master/app/src/main/java/com/morihacky/android/rxjava/rxbus/RxBusDemo_Bottom3Fragment.java) where a combo of the `publish` and `buffer` operators is used. For a more detailed explanation, you can also have a look at this [blog post](http://nerds.weddingpartyapp.com/tech/2015/01/05/debouncedbuffer-used-in-rxbus-example/).
+If you're looking for a more foolproof solution that accumulates "continuous" taps vs just the number of taps within a time span, look at the [EventBus Demo](https://github.com/kaushikgopal/Android-RxJava/blob/master/app/src/main/java/com/morihacky/android/rxjava/rxbus/RxBusDemo_Bottom3Fragment.java) where a combo of the `publish` and `buffer` operators is used. For a more detailed explanation, you can also have a look at this [blog post](https://kau.sh/blog/debouncedbuffer-with-rxjava/).
-### Instant/Auto searching (subject + debounce)
+### 3. Instant/Auto searching text listeners (using Subjects & debounce)
This is a demo of how events can be swallowed in a way that only the last one is respected. A typical example of this is instant search result boxes. As you type the word "Bruce Lee", you don't want to execute searches for B, Br, Bru, Bruce, Bruce, Bruce L ... etc. But rather intelligently wait for a couple of moments, make sure the user has finished typing the whole word, and then shoot out a single call for "Bruce Lee".
@@ -33,47 +59,63 @@ As you type in the input box, it will not shoot out log messages at every single
This is the debounce/throttleWithTimeout method in RxJava.
-### Retrofit and RxJava (zip, flatmap)
+### 4. Networking with Retrofit & RxJava (using zip, flatmap)
[Retrofit from Square](http://square.github.io/retrofit/) is an amazing library that helps with easy networking (even if you haven't made the jump to RxJava just yet, you really should check it out). It works even better with RxJava and these are examples hitting the GitHub API, taken straight up from the android demigod-developer Jake Wharton's talk at Netflix. You can [watch the talk](https://www.youtube.com/watch?v=aEuNBk1b5OE#t=2480) at this link. Incidentally, my motivation to use RxJava was from attending this talk at Netflix.
-Since it was a presentation, Jake only put up the most important code snippets in [his slides](https://speakerdeck.com/jakewharton/2014-1). Also he uses Java 8 in them, so I flushed those examples out in ~~good~~ old Java 6. (Note: you're most likely to hit the GitHub API quota pretty fast so send in an OAuth-token as a parameter if you want to keep running these examples often).
+(Note: you're most likely to hit the GitHub API quota pretty fast so send in an OAuth-token as a parameter if you want to keep running these examples often).
-### Orchestrating Observables. Make parallel network calls, then combine the result into a single data point (flatmap + zip)
+### 5. Two-way data binding for TextViews (using PublishSubject)
-The below ascii diagram expresses the intention of our next example with panache. f1,f2,3,f4,f5 are essentially network calls that when made, give back a result that's needed for a future calculation.
+Auto-updating views are a pretty cool thing. If you've dealt with Angular JS before, they have a pretty nifty concept called "two-way data binding", so when an HTML element is bound to a model/entity object, it constantly "listens" to changes on that entity and auto-updates its state based on the model. Using the technique in this example, you could potentially use a pattern like the [Presentation View Model pattern](http://martinfowler.com/eaaDev/PresentationModel.html) with great ease.
+While the example here is pretty rudimentary, the technique used to achieve the double binding using a `Publish Subject` is much more interesting.
- (flatmap)
- f1 ___________________ f3 _______
- (flatmap) | (zip)
- f2 ___________________ f4 _______| ___________ final output
- \ |
- \____________ f5 _______|
+### 6. Simple and Advanced polling (using interval and repeatWhen)
-The code for this example has already been written by one Mr.skehlet in the interwebs. Head over to [the gist](https://gist.github.com/skehlet/9418379) for the code. It's written in pure Java (6) so it's pretty comprehensible if you've understood the previous examples. I'll flush it out here again when time permits or I've run out of other compelling examples.
+This is an example of polling using RxJava Schedulers. This is useful in cases, where you want to constantly poll a server and possibly get new data. The network call is "simulated" so it forces a delay before return a resultant string.
-### Double binding with TextViews
+There are two variants for this:
-Auto-updating views are a pretty cool thing. If you've dealt with Angular JS before, they have a pretty nifty concept called "two-way data binding", where when an HTML element is bound to a model/entity object, it constantly "listens" to changes on that entity and auto-updates its state based on the model. Using the technique in this example, you could potentially use a pattern like the [Presentation View Model pattern](http://martinfowler.com/eaaDev/PresentationModel.html) with great ease.
+1. Simple Polling: say when you want to execute a certain task every 5 seconds
+2. Increasing Delayed Polling: say when you want to execute a task first in 1 second, then in 2 seconds, then 3 and so on.
-While the example here is pretty rudimentary, the technique used to achieve the double binding using a `Publish Subject` is much more interesting.
+The second example is basically a variant of [Exponential Backoff](https://github.com/kaushikgopal/RxJava-Android-Samples#exponential-backoff).
-### Polling with Schedulers
+Instead of using a RetryWithDelay, we use a RepeatWithDelay here. To understand the difference between Retry(When) and Repeat(When) I wouuld suggest Dan's [fantastic post on the subject](http://blog.danlew.net/2016/01/25/rxjavas-repeatwhen-and-retrywhen-explained/).
-This is an example of polling using RxJava Schedulers. This is useful in cases, where you want to constantly poll a server and possibly get new data. The network call is "simulated" so it forces a delay before return a resultant string.
+An alternative approach to delayed polling without the use of `repeatWhen` would be using chained nested delay observables. See [startExecutingWithExponentialBackoffDelay in the ExponentialBackOffFragment example](https://github.com/kaushikgopal/RxJava-Android-Samples/blob/master/app/src/main/java/com/morihacky/android/rxjava/fragments/ExponentialBackoffFragment.java#L111).
+
+### 7. Simple and Advanced exponential backoff (using delay and retryWhen)
+
+[Exponential backoff](https://en.wikipedia.org/wiki/Exponential_backoff) is a strategy where based on feedback from a certain output, we alter the rate of a process (usually reducing the number of retries or increasing the wait time before retrying or re-executing a certain process).
+
+The concept makes more sense with examples. RxJava makes it (relatively) simple to implement such a strategy. My thanks to [Mike](https://twitter.com/m_evans10) for suggesting the idea.
+
+#### Retry (if error) with exponential backoff
+
+Say you have a network failure. A sensible strategy would be to NOT keep retrying your network call every 1 second. It would be smart instead (nay... elegant!) to retry with increasing delays. So you try at second 1 to execute the network call, no dice? try after 10 seconds... negatory? try after 20 seconds, no cookie? try after 1 minute. If this thing is still failing, you got to give up on the network yo!
+
+We simulate this behaviour using RxJava with the [`retryWhen` operator](http://reactivex.io/documentation/operators/retry.html).
+
+`RetryWithDelay` code snippet courtesy:
+
+* http://stackoverflow.com/a/25292833/159825
+* Another excellent implementation via @[sddamico](https://github.com/sddamico) : https://gist.github.com/sddamico/c45d7cdabc41e663bea1
+* This one includes support for jittering, by @[leandrofavarin](https://github.com/leandrofavarin) : http://leandrofavarin.com/exponential-backoff-rxjava-operator-with-jitter
+
+Also look at the [Polling example](https://github.com/kaushikgopal/RxJava-Android-Samples#polling-with-schedulers) where we use a very similar Exponential backoff mechanism.
+
+#### "Repeat" with exponential backoff
-### RxBus - An event bus using RxJava + DebouncedBuffer
+Another variant of the exponential backoff strategy is to execute an operation for a given number of times but with delayed intervals. So you execute a certain operation 1 second from now, then you execute it again 10 seconds from now, then you execute the operation 20 seconds from now. After a grand total of 3 times you stop executing.
-Have a look at the accompanying blog posts for details on this demo:
+Simulating this behavior is actually way more simpler than the prevoius retry mechanism. You can use a variant of the `delay` operator to achieve this.
-1. [Implementing an event bus with RxJava](http://nerds.weddingpartyapp.com/tech/2014/12/24/implementing-an-event-bus-with-rxjava-rxbus/)
-2. [DebouncedBuffer used for the fancier variant of the demo](http://nerds.weddingpartyapp.com/tech/2014/12/24/secret-bonus-part-debouncedbuffer-used-in-rxbus-example/)
-3. [share/publish/refcount](http://nerds.weddingpartyapp.com/tech/2015/01/21/rxjava-share-publish-refcount-and-all-that-jazz/)
-### Form validation - using [`.combineLatest`](http://reactivex.io/documentation/operators/combinelatest.html)
+### 8. Form validation (using [`.combineLatest`](http://reactivex.io/documentation/operators/combinelatest.html))
-Thanks to Dan Lew for giving me this idea in the [fragmented podcast - episode #5](http://fragmentedpodcast.com/episodes/4/) (around the 4:30 mark).
+Thanks to Dan Lew for giving me this idea in the [fragmented podcast - episode #4](http://fragmentedpodcast.com/episodes/4/) (around the 4:30 mark).
`.combineLatest` allows you to monitor the state of multiple observables at once compactly at a single location. The example demonstrated shows how you can use `.combineLatest` to validate a basic form. There are 3 primary inputs for this form to be considered "valid" (an email, a password and a number). The form will turn valid (the text below turns blue :P) once all the inputs are valid. If they are not, an error is shown against the invalid inputs.
@@ -83,21 +125,33 @@ Note that the `Func3` function that checks for validity, kicks in only after ALL
The value of this technique becomes more apparent when you have more number of input fields in a form. Handling it otherwise with a bunch of booleans makes the code cluttered and kind of difficult to follow. But using `.combineLatest` all that logic is concentrated in a nice compact block of code (I still use booleans but that was to make the example more readable).
-### Retrieve data first from a cache, then a network call - using [`.concat`](http://reactivex.io/documentation/operators/concat.html)
-Using concat, you can retrieve information from an observable first (presumably this one is fast like retrieveing from a disk cache) and show preliminary data to a user. Subsequently, when the longer running 2nd observable is complete (say a network call), you can update the results on the interface using the latest information.
+### 9. Pseudo caching : retrieve data first from a cache, then a network call (using concat, concatEager, merge or publish)
+
+We have two source Observables: a disk (fast) cache and a network (fresh) call. Typically the disk Observable is much faster than the network Observable. But in order to demonstrate the working, we've also used a fake "slower" disk cache just to see how the operators behave.
+
+This is demonstrated using 4 techniques:
+
+1. [`.concat`](http://reactivex.io/documentation/operators/concat.html)
+2. [`.concatEager`](http://reactivex.io/RxJava/javadoc/rx/Observable.html#concatEager(java.lang.Iterable))
+3. [`.merge`](http://reactivex.io/documentation/operators/merge.html)
+4. [`.publish`](http://reactivex.io/RxJava/javadoc/rx/Observable.html#publish(rx.functions.Func1)) selector + merge + takeUntil
+
+The 4th technique is probably what you want to use eventually but it's interesting to go through the progression of techniques, to understand why.
-For the purposes of illustration i use an in-memory `List` (not an actual disk cache), then shoot out a real network call to the github api so it gives you a feel of how this can really be applied in production apps.
+`concat` is great. It retrieves information from the first Observable (disk cache in our case) and then the subsequent network Observable. Since the disk cache is presumably faster, all appears well and the disk cache is loaded up fast, and once the network call finishes we swap out the "fresh" results.
-**Update:**
+The problem with `concat` is that the subsequent observable doesn't even start until the first Observable completes. That can be a problem. We want all observables to start simultaneously but produce the results in a way we expect. Thankfully RxJava introduced `concatEager` which does exactly that. It starts both observables but buffers the result from the latter one until the former Observable finishes. This is a completely viable option.
-After a [conversation I had with @artem_zin](https://twitter.com/kaushikgopal/status/591271805211451392), we arrived at an alternative solution to the same problem. One that used the [`.merge`](http://reactivex.io/documentation/operators/merge.html) operator instead.
+Sometimes though, you just want to start showing the results immediately. Assuming the first observable (for some strange reason) takes really long to run through all its items, even if the first few items from the second observable have come down the wire it will forcibly be queued. You don't necessarily want to "wait" on any Observable. In these situations, we could use the `merge` operator. It interleaves items as they are emitted. This works great and starts to spit out the results as soon as they're shown.
-The `concat` (and the equivalent [`startWith`](http://reactivex.io/documentation/operators/startwith.html)) opeartor is strictly sequential, meaning all of the items emitted by the first Observable are emitted strictly before any of the items from the second Observable are emitted. So assuming the first observable (for some strange reason) takes really long to run through all its items, even if the first few items from the second observable have come down the wire it will forcibly be queued.
+Similar to the `concat` operator, if your first Observable is always faster than the second Observable you won't run into any problems. However the problem with `merge` is: if for some strange reason an item is emitted by the cache or slower observable *after* the newer/fresher observable, it will overwrite the newer content. Click the "MERGE (SLOWER DISK)" button in the example to see this problem in action. @JakeWharton and @swankjesse contributions go to 0! In the real world this could be bad, as it would mean the fresh data would get overridden by stale disk data.
-The `merge` operator on the other hand interleaves items as they are emitted. The problem here though is if for some strange reason an item is emitted by the cache or slower observable *after* the newer/fresher observable, it will overwrite the newer content. To account for this you have to monitor the "resultAge" somehow. This is demonstrated in the updated solution `PseudoCacheMergeFragment`.
+To solve this problem you can use merge in combination with the super nifty `publish` operator which takes in a "selector". I wrote about this usage in a [blog post](https://kau.sh/blog/rxjava-tip-for-the-day-share-publish-refcount-and-all-that-jazz/) but I have [Jedi JW](https://twitter.com/JakeWharton/status/786363146990649345) to thank for reminding of this technique. We `publish` the network observable and provide it a selector which starts emitting from the disk cache, up until the point that the network observable starts emitting. Once the network observable starts emitting, it ignores all results from the disk observable. This is perfect and handles any problems we might have.
-### Simple Timing demos using timer/interval/delay
+Previously, I was using the `merge` operator but overcoming the problem of results being overwritten by monitoring the "resultAge". See the old `PseudoCacheMergeFragment` example if you're curious to see this old implementation.
+
+### 10. Simple timing demos (using timer, interval and delay)
This is a super simple and straightforward example which shows you how to use RxJava's `timer`, `interval` and `delay` operators to handle a bunch of cases where you want to run a task at specific intervals. Basically say NO to Android `TimerTask`s.
@@ -107,50 +161,91 @@ Cases demonstrated here:
2. run a task constantly every 1s (there's a delay of 1s before the first task fires off)
3. run a task constantly every 1s (same as above but there's no delay before the first task fires off)
4. run a task constantly every 3s, but after running it 5 times, terminate automatically
+5. run a task A, pause for sometime, then execute Task B, then terminate
-### Exponential backoff
+### 11. RxBus : event bus using RxJava (using RxRelay (never terminating Subjects) and debouncedBuffer)
-[Exponential backoff](https://en.wikipedia.org/wiki/Exponential_backoff) is a strategy where based on feedback from a certain output, we alter the rate of a process (usually reducing the number of retries or increasing the wait time before retrying or re-executing a certain process).
+There are accompanying blog posts that do a much better job of explaining the details on this demo:
-The concept makes more sense with examples. RxJava makes it (relatively) simple to implement such a strategy. My thanks to [Mike](https://twitter.com/m_evans10) for suggesting the idea.
+1. [Implementing an event bus with RxJava](https://kau.sh/blog/implementing-an-event-bus-with-rxjava-rxbus/)
+2. [DebouncedBuffer used for the fancier variant of the demo](https://kau.sh/blog/debouncedbuffer-with-rxjava/)
+3. [share/publish/refcount](https://kau.sh/blog/rxjava-tip-for-the-day-share-publish-refcount-and-all-that-jazz/)
-#### Retry (if error) with exponential backoff
+### 12. Persist data on Activity rotations (using Subjects and retained Fragments)
-Say you have a network failure. A sensible strategy would be to NOT keep retrying your network call every 1 second. It would be smart instead (nay... elegant!) to retry with increasing delays. So you try at second 1 to execute the network call, no dice? try after 10 seconds... negatory? try after 20 seconds, no cookie? try after 1 minute. If this thing is still failing, you got to give up on the network yo!
+A common question that's asked when using RxJava in Android is, "how do i resume the work of an observable if a configuration change occurs (activity rotation, language locale change etc.)?".
-We simulate this behaviour using RxJava with the [`retryWhen` operator](http://reactivex.io/documentation/operators/retry.html).
+This example shows you one strategy viz. using retained Fragments. I started using retained fragments as "worker fragments" after reading this [fantastic post by Alex Lockwood](http://www.androiddesignpatterns.com/2013/04/retaining-objects-across-config-changes.html) quite sometime back.
-`RetryWithDelay` code snippet courtesy:
+Hit the start button and rotate the screen to your heart's content; you'll see the observable continue from where it left off.
-* http://stackoverflow.com/a/25292833/159825
-* Another excellent implementation via @[sddamico](https://github.com/sddamico) : https://gist.github.com/sddamico/c45d7cdabc41e663bea1
+*There are certain quirks about the "hotness" of the source observable used in this example. Check [my blog post](https://kau.sh/blog/a-note-about-the-warmth-share-operator/) out where I explain the specifics.*
-#### "Repeat" with exponential backoff
+I have since rewritten this example using an alternative approach. While the [`ConnectedObservable` approach worked](https://github.com/kaushikgopal/RxJava-Android-Samples/blob/master/app/src/main/java/com/morihacky/android/rxjava/fragments/RotationPersist1WorkerFragment.java#L20) it enters the lands of "multicasting" which can be tricky (thread-safety, .refcount etc.). Subjects on the other hand are far more simple. You can see it rewritten [using a `Subject` here](https://github.com/kaushikgopal/RxJava-Android-Samples/blob/master/app/src/main/java/com/morihacky/android/rxjava/fragments/RotationPersist2WorkerFragment.java#L22).
-Another variant of the exponential backoff strategy is to execute an operation for a given number of times but with delayed intervals. So you execute a certain operation 1 second from now, then you execute it again 10 seconds from now, then you execute the operation 20 seconds from now. After a grand total of 3 times you stop executing.
+I wrote [another blog post](https://tech.instacart.com/how-to-think-about-subjects-part-1/) on how to think about Subjects where I go into some specifics.
-Simulating this behavior is actually way more simpler than the prevoius retry mechanism. You can use a variant of the `delay` operator to achieve this.
-### Rotation Persist
+### 13. Networking with Volley
-A common question that's asked when using RxJava in Android is, "how do i resume the work of an observable if a configuration change occurs (activity rotation, language locale change etc.)?".
+[Volley](http://developer.android.com/training/volley/index.html) is another networking library introduced by [Google at IO '13](https://www.youtube.com/watch?v=yhv8l9F44qo). A kind citizen of github contributed this example so we know how to integrate Volley with RxJava.
-This example shows you one strategy viz. using retained Fragments. I started using retained fragments as "worker fragments" after reading this [fantastic post by Alex Lockwood](http://www.androiddesignpatterns.com/2013/04/retaining-objects-across-config-changes.html) quite sometime back.
+### 14. Pagination with Rx (using Subjects)
-Hit the start button and rotate the screen to your heart's content; you'll see the observable continue from where it left off.
+I leverage the simple use of a Subject here. Honestly, if you don't have your items coming down via an `Observable` already (like through Retrofit or a network request), there's no good reason to use Rx and complicate things.
+
+This example basically sends the page number to a Subject, and the subject handles adding the items. Notice the use of `concatMap` and the return of an `Observable` from `_itemsFromNetworkCall`.
-*There are certain quirks about the "hotness" of the source observable used in this example. Check [my blog post](http://blog.kaush.co/2015/07/11/a-note-about-the-warmth-share-operator/) out where I explain the specifics.*
+For kicks, I've also included a `PaginationAutoFragment` example, this "auto-paginates" without us requiring to hit a button. It should be simple to follow if you got how the previous example works.
-## Work in Progress:
+Here are some other fancy implementations (while i enjoyed reading them, i didn't land up using them for my real world app cause personally i don't think it's necessary):
-Examples that I would like to have here, but haven't found the time yet to flush out.
+* [Matthias example of an Rx based pager](https://gist.github.com/mttkay/24881a0ce986f6ec4b4d)
+* [Eugene's very comprehensive Pagination sample](https://github.com/matzuk/PaginationSample)
+* [Recursive Paging example](http://stackoverflow.com/questions/28047272/handle-paging-with-rxjava)
+### 15. Orchestrating Observable: make parallel network calls, then combine the result into a single data point (using flatmap & zip)
-### Pagination
+The below ascii diagram expresses the intention of our next example with panache. f1,f2,f3,f4,f5 are essentially network calls that when made, give back a result that's needed for a future calculation.
-a. Simple pagination
-b. Optimized pagination
+ (flatmap)
+ f1 ___________________ f3 _______
+ (flatmap) | (zip)
+ f2 ___________________ f4 _______| ___________ final output
+ \ |
+ \____________ f5 _______|
+
+The code for this example has already been written by one Mr.skehlet in the interwebs. Head over to [the gist](https://gist.github.com/skehlet/9418379) for the code. It's written in pure Java (6) so it's pretty comprehensible if you've understood the previous examples. I'll flush it out here again when time permits or I've run out of other compelling examples.
+
+### 16. Simple Timeout example (using timeout)
+
+This is a simple example demonstrating the use of the `.timeout` operator. Button 1 will complete the task before the timeout constraint, while Button 2 will force a timeout error.
+
+Notice how we can provide a custom Observable that indicates how to react under a timeout Exception.
+
+### 17. Setup and teardown resources (using `using`)
+
+The [operator `using`](http://reactivex.io/documentation/operators/using.html) is relatively less known and notoriously hard to Google. It's a beautiful API that helps to setup a (costly) resource, use it and then dispose off in a clean way.
+
+The nice thing about this operator is that it provides a mechansim to use potentially costly resources in a tightly scoped manner. using -> setup, use and dispose. Think DB connections (like Realm instances), socket connections, thread locks etc.
+
+### 18. Multicast Playground
+
+Multicasting in Rx is like a dark art. Not too many folks know how to pull it off without concern. This example condiers two subscribers (in the forms of buttons) and allows you to add/remove subscribers at different points of time and see how the different operators behave under those circumstances.
+
+The source observale is a timer (`interval`) observable and the reason this was chosen was to intentionally pick a non-terminating observable, so you can test/confirm if your multicast experiment will leak.
+
+_I also gave a talk about [Multicasting in detail at 360|Andev](https://speakerdeck.com/kaushikgopal/rx-by-example-volume-3-the-multicast-edition). If you have the inclination and time, I highly suggest watching that talk first (specifically the Multicast operator permutation segment) and then messing around with the example here._
+
+## Rx 2.x
+
+All the examples here have been migrated to use RxJava 2.X.
+
+* Have a look at [PR #83 to see the diff of changes between RxJava 1 and 2](https://github.com/kaushikgopal/RxJava-Android-Samples/pull/83/files)
+* [What's different in Rx 2.x](https://github.com/ReactiveX/RxJava/wiki/What's-different-in-2.0)
+
+We use [David Karnok's Interop library](https://github.com/akarnokd/RxJava2Interop) in some cases as certain libraries like RxBindings, RxRelays, RxJava-Math etc. have not been ported yet to 2.x.
## Contributing:
@@ -158,6 +253,18 @@ I try to ensure the examples are not overly contrived but reflect a real-world u
I'm wrapping my head around RxJava too so if you feel there's a better way of doing one of the examples mentioned above, open up an issue explaining how. Even better, send a pull request.
+
+## Sponsorship (Memory Management/Profiling)
+
+Rx threading is messy business. To help, this project uses YourKit tools for analysis.
+
+
+
+
+YourKit supports open source projects with innovative and intelligent tools
+for monitoring and profiling Java applications. YourKit is the creator of YourKit Java Profiler.
+
+
## License
Licensed under the Apache License, Version 2.0 (the "License").
diff --git a/app/build.gradle b/app/build.gradle
index 8fedb1bc..edbcd31c 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,35 +1,78 @@
+buildscript {
+ repositories {
+// mavenCentral()
+ jcenter()
+ }
+ dependencies {
+ classpath 'me.tatarka:gradle-retrolambda:3.6.0'
+ classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}"
+ }
+
+ // Exclude the lombok version that the android plugin depends on.
+ configurations.classpath.exclude group: 'com.android.tools.external.lombok'
+}
+
apply plugin: 'com.android.application'
+apply plugin: 'me.tatarka.retrolambda'
+apply plugin: 'com.f2prateek.javafmt'
+apply plugin: 'kotlin-android'
dependencies {
- compile 'com.android.support:support-v13:21.0.2'
+ compile 'com.android.support:multidex:1.0.1'
+ compile "com.android.support:support-v13:${supportLibVersion}"
+ compile "com.android.support:appcompat-v7:${supportLibVersion}"
+ compile "com.android.support:recyclerview-v7:${supportLibVersion}"
+
+ compile 'com.github.kaushikgopal:CoreTextUtils:c703fa12b6'
+ compile "com.jakewharton:butterknife:${butterKnifeVersion}"
+ kapt "com.jakewharton:butterknife-compiler:${butterKnifeVersion}"
+ compile 'com.jakewharton.timber:timber:4.5.1'
+ compile "com.squareup.retrofit2:retrofit:${retrofitVersion}"
+ compile "com.squareup.retrofit2:converter-gson:${retrofitVersion}"
+ compile "com.squareup.okhttp3:okhttp:${okhttpVersion}"
+ compile "com.squareup.okhttp3:okhttp-urlconnection:${okhttpVersion}"
+ compile 'com.mcxiaoke.volley:library:1.0.19'
+
+ compile "org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}"
+ compile "com.nhaarman:mockito-kotlin:${mockitoKotlinVersion}"
+
+ compile "android.arch.lifecycle:runtime:${archComponentsVersion}"
+ compile "android.arch.lifecycle:extensions:${archComponentsVersion}"
+ kapt "android.arch.lifecycle:compiler:${archComponentsVersion}"
+
+ // ----------------------------------
+ // Rx dependencies
+
+ compile 'io.reactivex.rxjava2:rxjava:2.0.7'
- compile 'io.reactivex:rxandroid:1.0.1'
// Because RxAndroid releases are few and far between, it is recommended you also
// explicitly depend on RxJava's latest version for bug fixes and new features.
- compile 'io.reactivex:rxjava:1.0.14'
- compile 'io.reactivex:rxjava-math:1.0.0'
- compile 'com.jakewharton.rxbinding:rxbinding:0.2.0'
-
- compile 'com.jakewharton:butterknife:5.1.1'
- compile 'com.jakewharton.timber:timber:2.4.2'
- compile 'com.squareup.retrofit:retrofit:1.6.1'
- compile 'com.squareup.okhttp:okhttp:2.0.0'
- compile 'com.squareup.okhttp:okhttp-urlconnection:2.0.0'
-
- debugCompile 'com.squareup.leakcanary:leakcanary-android:1.3'
- releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.3'
+ compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
+
+ compile 'com.jakewharton.rx:replaying-share-kotlin:2.0.0'
+ compile "com.github.akarnokd:rxjava2-extensions:0.16.0"
+ compile 'com.jakewharton.rxrelay2:rxrelay:2.0.0'
+
+ compile 'com.jakewharton.rxbinding2:rxbinding:2.0.0'
+ compile 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
+
+ // ----------------------------------
+
+ debugCompile 'com.squareup.leakcanary:leakcanary-android:1.5.1'
+ releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.5.1'
}
android {
- compileSdkVersion 23
- buildToolsVersion '23'
+ compileSdkVersion sdkVersion
+ buildToolsVersion buildToolsVrs
defaultConfig {
applicationId "com.morihacky.android.rxjava"
- minSdkVersion 14
- targetSdkVersion 22
- versionCode 1
- versionName "1.0"
+ minSdkVersion 15
+ targetSdkVersion sdkVersion
+ versionCode 2
+ versionName "1.2"
+ multiDexEnabled true
}
buildTypes {
release {
@@ -37,4 +80,14 @@ android {
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
+ sourceSets {
+ main.java.srcDirs += 'src/main/kotlin'
+ }
+ compileOptions {
+ sourceCompatibility JavaVersion.VERSION_1_8
+ targetCompatibility JavaVersion.VERSION_1_8
+ }
+ packagingOptions {
+ pickFirst 'META-INF/rxjava.properties'
+ }
}
\ No newline at end of file
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 7466dc56..3b469d7c 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -21,6 +21,8 @@
+
+
diff --git a/app/src/main/java/com/morihacky/android/rxjava/MainActivity.java b/app/src/main/java/com/morihacky/android/rxjava/MainActivity.java
index 41bc79ae..068a393d 100644
--- a/app/src/main/java/com/morihacky/android/rxjava/MainActivity.java
+++ b/app/src/main/java/com/morihacky/android/rxjava/MainActivity.java
@@ -2,56 +2,58 @@
import android.os.Bundle;
import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentActivity;
+import android.support.v7.app.AppCompatActivity;
import com.morihacky.android.rxjava.fragments.MainFragment;
import com.morihacky.android.rxjava.fragments.RotationPersist1WorkerFragment;
import com.morihacky.android.rxjava.fragments.RotationPersist2WorkerFragment;
import com.morihacky.android.rxjava.rxbus.RxBus;
-public class MainActivity
- extends FragmentActivity {
+public class MainActivity extends AppCompatActivity {
- private RxBus _rxBus = null;
+ private RxBus _rxBus = null;
- // This is better done with a DI Library like Dagger
- public RxBus getRxBusSingleton() {
- if (_rxBus == null) {
- _rxBus = new RxBus();
- }
+ @Override
+ public void onBackPressed() {
+ super.onBackPressed();
+ _removeWorkerFragments();
+ }
- return _rxBus;
- }
+ @Override
+ protected void onCreate(Bundle savedInstanceState) {
+ super.onCreate(savedInstanceState);
- @Override
- public void onBackPressed() {
- super.onBackPressed();
- _removeWorkerFragments();
+ if (savedInstanceState == null) {
+ getSupportFragmentManager()
+ .beginTransaction()
+ .replace(android.R.id.content, new MainFragment(), this.toString())
+ .commit();
}
+ }
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
-
- if (savedInstanceState == null) {
- getSupportFragmentManager().beginTransaction()
- .replace(android.R.id.content, new MainFragment(), this.toString())
- .commit();
- }
+ // This is better done with a DI Library like Dagger
+ public RxBus getRxBusSingleton() {
+ if (_rxBus == null) {
+ _rxBus = new RxBus();
}
- private void _removeWorkerFragments() {
- Fragment frag = getSupportFragmentManager()//
- .findFragmentByTag(RotationPersist1WorkerFragment.class.getName());
+ return _rxBus;
+ }
- if (frag != null) {
- getSupportFragmentManager().beginTransaction().remove(frag).commit();
- }
+ private void _removeWorkerFragments() {
+ Fragment frag =
+ getSupportFragmentManager()
+ .findFragmentByTag(RotationPersist1WorkerFragment.class.getName());
+
+ if (frag != null) {
+ getSupportFragmentManager().beginTransaction().remove(frag).commit();
+ }
- frag = getSupportFragmentManager()//
- .findFragmentByTag(RotationPersist2WorkerFragment.class.getName());
+ frag =
+ getSupportFragmentManager()
+ .findFragmentByTag(RotationPersist2WorkerFragment.class.getName());
- if (frag != null) {
- getSupportFragmentManager().beginTransaction().remove(frag).commit();
- }
+ if (frag != null) {
+ getSupportFragmentManager().beginTransaction().remove(frag).commit();
}
-}
\ No newline at end of file
+ }
+}
diff --git a/app/src/main/java/com/morihacky/android/rxjava/MyApp.java b/app/src/main/java/com/morihacky/android/rxjava/MyApp.java
index b66f855f..23a90b23 100644
--- a/app/src/main/java/com/morihacky/android/rxjava/MyApp.java
+++ b/app/src/main/java/com/morihacky/android/rxjava/MyApp.java
@@ -1,31 +1,43 @@
package com.morihacky.android.rxjava;
-import android.app.Application;
+import android.support.multidex.MultiDexApplication;
+import com.morihacky.android.rxjava.volley.MyVolley;
import com.squareup.leakcanary.LeakCanary;
import com.squareup.leakcanary.RefWatcher;
import timber.log.Timber;
-public class MyApp
- extends Application {
+public class MyApp extends MultiDexApplication {
- private static MyApp _instance;
- private RefWatcher _refWatcher;
+ private static MyApp _instance;
+ private RefWatcher _refWatcher;
- public static MyApp get() {
- return _instance;
- }
+ public static MyApp get() {
+ return _instance;
+ }
+
+ public static RefWatcher getRefWatcher() {
+ return MyApp.get()._refWatcher;
+ }
+
+ @Override
+ public void onCreate() {
+ super.onCreate();
- public static RefWatcher getRefWatcher() {
- return MyApp.get()._refWatcher;
+ if (LeakCanary.isInAnalyzerProcess(this)) {
+ // This process is dedicated to LeakCanary for heap analysis.
+ // You should not init your app in this process.
+ return;
}
- @Override
- public void onCreate() {
- super.onCreate();
+ _instance = (MyApp) getApplicationContext();
+ _refWatcher = LeakCanary.install(this);
- _instance = (MyApp) getApplicationContext();
- _refWatcher = LeakCanary.install(this);
+ // for better RxJava debugging
+ //RxJavaHooks.enableAssemblyTracking();
- Timber.plant(new Timber.DebugTree());
- }
+ // Initialize Volley
+ MyVolley.init(this);
+
+ Timber.plant(new Timber.DebugTree());
+ }
}
diff --git a/app/src/main/java/com/morihacky/android/rxjava/RxUtils.java b/app/src/main/java/com/morihacky/android/rxjava/RxUtils.java
deleted file mode 100644
index 100b9aa0..00000000
--- a/app/src/main/java/com/morihacky/android/rxjava/RxUtils.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package com.morihacky.android.rxjava;
-
-import rx.Subscription;
-import rx.subscriptions.CompositeSubscription;
-
-public class RxUtils {
-
- public static void unsubscribeIfNotNull(Subscription subscription) {
- if (subscription != null) {
- subscription.unsubscribe();
- }
- }
-
- public static CompositeSubscription getNewCompositeSubIfUnsubscribed(CompositeSubscription subscription) {
- if (subscription == null || subscription.isUnsubscribed()) {
- return new CompositeSubscription();
- }
-
- return subscription;
- }
-}
diff --git a/app/src/main/java/com/morihacky/android/rxjava/fragments/BaseFragment.java b/app/src/main/java/com/morihacky/android/rxjava/fragments/BaseFragment.java
index 429f8ba0..4ce242f3 100644
--- a/app/src/main/java/com/morihacky/android/rxjava/fragments/BaseFragment.java
+++ b/app/src/main/java/com/morihacky/android/rxjava/fragments/BaseFragment.java
@@ -4,13 +4,12 @@
import com.morihacky.android.rxjava.MyApp;
import com.squareup.leakcanary.RefWatcher;
-public class BaseFragment
- extends Fragment {
+public class BaseFragment extends Fragment {
- @Override
- public void onDestroy() {
- super.onDestroy();
- RefWatcher refWatcher = MyApp.getRefWatcher();
- refWatcher.watch(this);
- }
+ @Override
+ public void onDestroy() {
+ super.onDestroy();
+ RefWatcher refWatcher = MyApp.getRefWatcher();
+ refWatcher.watch(this);
+ }
}
diff --git a/app/src/main/java/com/morihacky/android/rxjava/fragments/BufferDemoFragment.java b/app/src/main/java/com/morihacky/android/rxjava/fragments/BufferDemoFragment.java
index 6a91aec5..bf51b85c 100644
--- a/app/src/main/java/com/morihacky/android/rxjava/fragments/BufferDemoFragment.java
+++ b/app/src/main/java/com/morihacky/android/rxjava/fragments/BufferDemoFragment.java
@@ -9,145 +9,152 @@
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ListView;
-import butterknife.ButterKnife;
-import butterknife.InjectView;
-import com.jakewharton.rxbinding.view.RxView;
-import com.jakewharton.rxbinding.view.ViewClickEvent;
+
+import com.jakewharton.rxbinding2.view.RxView;
import com.morihacky.android.rxjava.R;
import com.morihacky.android.rxjava.wiring.LogAdapter;
+
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
-import rx.Observer;
-import rx.Subscription;
-import rx.android.schedulers.AndroidSchedulers;
-import rx.functions.Func1;
+
+import butterknife.BindView;
+import butterknife.ButterKnife;
+import butterknife.Unbinder;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.observers.DisposableObserver;
import timber.log.Timber;
/**
* This is a demonstration of the `buffer` Observable.
*
- * The buffer observable allows taps to be collected only within a time span. So taps outside the
+ *
The buffer observable allows taps to be collected only within a time span. So taps outside the
* 2s limit imposed by buffer will get accumulated in the next log statement.
*
- * If you're looking for a more foolproof solution that accumulates "continuous" taps vs
- * a more dumb solution as show below (i.e. number of taps within a timespan)
- * look at {@link com.morihacky.android.rxjava.rxbus.RxBusDemo_Bottom3Fragment} where a combo
- * of `publish` and `buffer` is used.
+ *
If you're looking for a more foolproof solution that accumulates "continuous" taps vs a more
+ * dumb solution as show below (i.e. number of taps within a timespan) look at {@link
+ * com.morihacky.android.rxjava.rxbus.RxBusDemo_Bottom3Fragment} where a combo of `publish` and
+ * `buffer` is used.
*
- * Also http://nerds.weddingpartyapp.com/tech/2015/01/05/debouncedbuffer-used-in-rxbus-example/
+ *