Book: The Clean Way to Use Rx
This work, groups the different practices used in the implementation of software components through Rx extensions. These practices are organized into 35 application items, and for each item, it is analyzed, which are the recommended code practices and the practices to avoid.
It could also be said that this document is the compilation of good practices learned through the own experience acquired in business projects, recommendations received from forums, blogs, workshops and in general from analyzes given by experts in the area, including the recommendations given in the official sites of each extension.
This book is also intended as a practical reference manual for implementing Rx code. That is why much of the book's material consists of examples of code snippets written in the main programming languages for both Frontend (Mobile, Web; that is, JavaScript, Swift, Java) such as Backend.
The concepts studied in each of the items are agnostic to the programming language, there are few cases in which a certain capacity is not available in an extension and in which case the respective annotation is made in the item.
It is intended that once the concepts of each item have been studied, the reader benefits from a greater understanding of how Rx works.
Readers will also be equipped with tools to apply good practices that are ultimately reflected in the solutions in the area of:
- Clean Code.
- Best performance:
- Mitigate bugs scenarios.
Rules summary
Foundation
Ítem 1: From Imperative to Reactive
Ítem 2: Focus on pure functions
Ítem 3: Check the nature of the streams when they are linked
Ítem 4: Decide when to use an Observable type empty or never
Be Clean
Ítem 5: Keep clean the operators' chain
Ítem 6: Define functional operator chains
Ítem 7: Do not nest subscriptions, use operator chain
Ítem 8: Use Rx when there are events involved
Ítem 9: Do not orchestrate Rx operations with imperative programming
Ítem 10: Do not include Rx code in Do operators
Ítem 11: Propagate wrappers, not units
Ítem 12: Avoid propagating null values, turn to Optionals
Ítem 13: Remember you can use a filter, instead of if sentence
Ítem 14: It is possible to divide the emission when if-else is presented
Ítem 15: Sharing code is not the same as sharing emissions
Ítem 16: Not everything is delegated to the Observer
Ítem 17: Delay as much as possible the definition of the Schedule
Flow dependencies
Ítem 18: Check completion or error events when using filters
Ítem 19: Beware of reduction operators on infinite streams
Ítem 20: Maintain consistency like the stream
Ítem 21: Be careful when you depend on onComplete
Ítem 22: An additional step in the operator chain
Ítem 23: Orchestrating and combining effectively
Operators
Ítem 24: Properly select operators
Ítem 25: Use the map operator only for transformations
Timing
Ítem 26: Make sure you execute the tasks at the right time
Ítem 27: Control execution times on dependent tasks
Error handling
Ítem 28: Handling errors
Multicasting
Ítem 29: Share Observables, share Observers or both
Multi-threading
Ítem 30: Rx is single-threaded by default
Ítem 31: Do the order of the subscribeOn and observeOn operators matter?
Ítem 32: Some operators bring a predefined Scheduler
Ítem 33: Negotiating with UI
Optimizing
Ítem 34: Properly canceling the subscription
Ítem 35: When to use Subjects or Traits?
Versions of IDEs and technologies used.
- Xcode 11.5 - Swift 5
- Android Studio 4.0 - Java 1.8.0
- Visual Studio Code 1.47.1 - TypeScript 3.8.3 - Angular 9.1.0
Other technologies
The reader will also be able to access the public repositories written for each technology at: