Update wiki to reflect 3.x (tracking issue)

[akarnokd]

This is the overview of the suggested/planned changes to the Wiki. Text in bold are for extra considerations/options.

• Additional-Reading.md: review links, add newer links to blogs and topics
• Alphabetical-List-of-Observable-Operators.md: remove non-standard, deleted & otherwise project-external operators, add newer operators, link to the categorized other .md files and sections in the wiki.
• Alphabetical-List-of-3rd-party-operators.md: create page and list operators that used to be in RxJava and/or interesting enough, but available in 3rd party libraries, such as rxjava2-extras.
• Async-Operators: review the operator set, point to RxJava2Extensions project, add fancy descriptions like in 2.x: Expand Creating-Observables.md wiki #6131.
• Backpressure: update wording, remove unavailable operators, fix image links, make sure examples are in Java.
• Backpressure-(2.0).md: maybe review, should be okay as it has been recently added
• Blocking-Observable-Operators.md: update to blockingX methods, add fancy descriptions like in 2.x: Expand Creating-Observables.md wiki #6131, existing operators only, fix image link
• Combining-Observables.md: expand operator list (concat/eager/withLatestFrom missing?), fancy like 2.x: Expand Creating-Observables.md wiki #6131, link to RxJava2Extensions or explain join patterns here.
• Conditional-and-Boolean-Operators.md: review operators, link/explain extensions ops, fancy like 2.x: Expand Creating-Observables.md wiki #6131
• Connectable-Observable-Operators.md: add newer operators, have examples in Java, fix image links
• Creating-Observables.md: add generate
• Error-Handling-Operators.md: review set, fancy like 2.x: Expand Creating-Observables.md wiki #6131
• Error-Handling.md: review, only existing exceptions, include the error handling explanations from the What's different page.
• Filtering-Observables.md: review, remove nonexistent operators, fancy like 2.x: Expand Creating-Observables.md wiki #6131
• Getting-Started.md: fix versions and maven group ids, remove troubleshooting section?, add getting started from Readme.md?
• Home.md: RxJava project is no longer polyglot, link to the other RxYYY projects instead, review "sales pitch", review/expand libraries and check for true v2 version support, mention the v1 interop for the older libs
• How-To-Use-RxJava.md: turn non-Java examples into Java, use only Java examples, fix image links, review the create section
• How-to-Contribute.md: needs extensive rewrite and detailing
• Implementing-Your-Own-Operators.md: needs extensive rewrite, somewhat redundant with Writing-Operators-(2.0).md.
• Implementing-custom-operators-(draft).md: v1 only, unlist it and add banner 1.x content!
• Mathematical-and-Aggregate-Operators.md: review operator list, link to RxJava2Extensions, fancy like 2.x: Expand Creating-Observables.md wiki #6131, concat is not an aggregator
• Observable-Utility-Operators.md: review set, add new operators, fancy like 2.x: Expand Creating-Observables.md wiki #6131
• Observable.md: pretty barebone, perhaps list all reactive types and their support interfaces with some descriptions
• Parallel-flows.md: list parallel operators, sequentialDelayError, fancy like 2.x: Expand Creating-Observables.md wiki #6131, no longer experimental/beta
• Phantom-Operators.md: dumping ground for old/never relaized operators, remove or add warning about historical/museum content?
• Plugins.md: rewrite for RxJavaPlugins and related components
• Problem-Solving-Examples-in-RxJava.md: Fibonacci is not a relevant problem, not sure what problem examples could be listed here instead: how to wrap/bridge to existing technologies? How to get REST data into a listview?
• Reactive-Streams.md: remove v1 related details, wording: Java Flow has been shipped.
• Scheduler.md: needs extensive expansion, also add system properties, perhaps mention exotic schedulers in RxJava2Extensions, perhaps show how to write a scheduler.
• String-Observables.md: the RxJava2Extensions only has a few string operators, link to them?, fancy like 2.x: Expand Creating-Observables.md wiki #6131
• Subject.md: needs extensive expansion: show the various subject types, their specific methods, examples.
• The-RxJava-Android-Module.md: maybe just link to RxAndroid and remove the rest?
• Transforming-Observables.md: review and add new operators, fancy like 2.x: Expand Creating-Observables.md wiki #6131
• What's-different-in-2.0.md: fine
• Writing-operators-for-2.0.md: expand: fusion topics, example operators
• _Footer.md: fine
• _Sidebar.md: not sure if this is actually displayed as there is the _Sidebar.md.md too. Sync the two.
• _Sidebar.md.md: reorganize a bit (list categories under "all operators"), remove v1 references, move v2 pages up

[khkong]

@akarnokd
An invalid link was found in the Additional-Reading.md file.
Can I merge request a partial update?

[MorrisLaw]

Maybe you can start picking up these tasks to get familiar with making PRs to this repo @ddunig2

[ddunig2]

@akarnokd may I help contribute to this project?

[akarnokd]

@ddunig2 Sure.

[ddunig2]

@akarnokd im not sure if this issue is closed or not but I am fairly new to GitHub contribution. If this happens to be closed, whats a good first issue on this project?

[akarnokd]

Closed issues have a big red button indicating as such:

Otherwise, we don't have any good first issues at the moment. However, you could try and backport #6729 to the RxJava 2.x branch. Please consult a Git/Github tutorial if you don't know how to do things.

[ddunig2]

@akarnokd Im somewhat familiar with GitHub. By backport do you mean committing the fixes in #6729 to the 2.x branch?

[akarnokd]

You'd have to manually apply the changes in the source code of the 2.x branch as the files and locations do not match for an automatic backport.

[ddunig2]

@akarnokd I'm having trouble getting the project on my local machine without any errors. I forked and download it and wanted to make the changes on the eclipse IDE. Any idea why that may be?

[akarnokd]

What are those errors? Which Eclipse version are you using?

[ddunig2]

@akarnokd Im using Eclipse-java 2019-09, java jdk13. The i just recloned it to check the issue and atm has no issue warning but when I run .\gradlew build, it fails

FAILURE: Build failed with an exception.

• Where:
  Settings file 'C:\Users\lugdu\Desktop\GitHubContribution\RxJava\settings.gradle'

• What went wrong:
  Could not compile settings file 'C:\Users\lugdu\Desktop\GitHubContribution\RxJava\settings.gradle'.

startup failed:
General error during semantic analysis: Unsupported class file major version 57

java.lang.IllegalArgumentException: Unsupported class file major version 57
at groovyjarjarasm.asm.ClassReader.(ClassReader.java:184)
at groovyjarjarasm.asm.ClassReader.(ClassReader.java:166)
at groovyjarjarasm.asm.ClassReader.(ClassReader.java:152)
at groovyjarjarasm.asm.ClassReader.(ClassReader.java:273)
at org.codehaus.groovy.ast.decompiled.AsmDecompiler.parseClass(AsmDecompiler.java:81)
at org.codehaus.groovy.control.ClassNodeResolver.findDecompiled(ClassNodeResolver.java:254)
at org.codehaus.groovy.control.ClassNodeResolver.tryAsLoaderClassOrScript(ClassNodeResolver.java:192)
at org.codehaus.groovy.control.ClassNodeResolver.findClassNode(ClassNodeResolver.java:172)
at org.codehaus.groovy.control.ClassNodeResolver.resolveName(ClassNodeResolver.java:128)
at org.codehaus.groovy.ast.decompiled.AsmReferenceResolver.resolveClassNullable(AsmReferenceResolver.java:59)
at org.codehaus.groovy.ast.decompiled.AsmReferenceResolver.resolveClass(AsmReferenceResolver.java:46)
at org.codehaus.groovy.ast.decompiled.AsmReferenceResolver.resolveNonArrayType(AsmReferenceResolver.java:81)
at org.codehaus.groovy.ast.decompiled.AsmReferenceResolver.resolveType(AsmReferenceResolver.java:72)
at org.codehaus.groovy.ast.decompiled.MemberSignatureParser.createMethodNode(MemberSignatureParser.java:55)
at org.codehaus.groovy.ast.decompiled.DecompiledClassNode.lazyInitMembers(DecompiledClassNode.java:195)
at org.codehaus.groovy.ast.decompiled.DecompiledClassNode.getDeclaredMethods(DecompiledClassNode.java:121)
at org.codehaus.groovy.ast.ClassNode.getMethods(ClassNode.java:912)
at org.codehaus.groovy.ast.ClassNode.tryFindPossibleMethod(ClassNode.java:1280)
at org.codehaus.groovy.control.StaticImportVisitor.transformMethodCallExpression(StaticImportVisitor.java:252)
at org.codehaus.groovy.control.StaticImportVisitor.transform(StaticImportVisitor.java:112)
at org.codehaus.groovy.ast.ClassCodeExpressionTransformer.visitExpressionStatement(ClassCodeExpressionTransformer.java:144)
at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:42)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:110)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:121)
at org.codehaus.groovy.ast.ClassCodeExpressionTransformer.visitConstructorOrMethod(ClassCodeExpressionTransformer.java:55)
at org.codehaus.groovy.control.StaticImportVisitor.visitConstructorOrMethod(StaticImportVisitor.java:88)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructor(ClassCodeVisitorSupport.java:128)
at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1099)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:54)
at org.codehaus.groovy.control.StaticImportVisitor.visitClass(StaticImportVisitor.java:82)
at org.codehaus.groovy.control.CompilationUnit$14.call(CompilationUnit.java:717)
at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1095)
at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:649)
at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:627)
at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:604)
at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:390)
at groovy.lang.GroovyClassLoader.access$300(GroovyClassLoader.java:89)
at groovy.lang.GroovyClassLoader$5.provide(GroovyClassLoader.java:330)
at groovy.lang.GroovyClassLoader$5.provide(GroovyClassLoader.java:327)
at org.codehaus.groovy.runtime.memoize.ConcurrentCommonCache.getAndPut(ConcurrentCommonCache.java:147)
at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:325)
at org.gradle.groovy.scripts.internal.DefaultScriptCompilationHandler.compileScript(DefaultScriptCompilationHandler.java:133)

[akarnokd]

Install a Jdk 8 runtime and have Eclipse use it as a target:

[ddunig2]

@akarnokd of great, I don't notice any errors. Now, I am on the 3x branch, Im not too familiar with backporting, would you be able to give me a quick guide as to what happens from here? So you mentioned that i would have to manually change the source code in the 2x branch to match the 3x branch, Can I get a little more detail. Am I changing the whole code or am I looking at a specific package?

[akarnokd]

No.

1. Check out the 2.x branch
2. Create a new branch of of 2.x named JavadocCleanup_1203
3. Open the changed files of 3.x: Fix self-see references, some comments #6729 in a browser
4. For each file, expand the sections until you see the method name. For the first entry, it is public final Single<Long> count() {
5. Locate this file and method in your IDE
6. Apply the changes you see on the web page: remove lines or add lines
7. Once done, make sure you have your own fork as remote in the Git repositories view under RxJava
8. Add a commit message and commit the changes, and then push to your fork.
9. Go to the PR page and wait for your branch to pop up to make a PR
10. Make a PR and fill in some explanation about what you've done.

[ddunig2]

@akarnokd thank you that was fairly descriptive. The first change I see is the removal of the @see #count but nothing in the method itself. Is that what you are referring to?

[ddunig2]

@akarnokd I made a PR!

[VovaStelmashchuk]

Doc https://github.com/ReactiveX/RxJava/blob/2.x/docs/Filtering-Observables.md, Looks like up to date. Can you put checkmark?

[skywall]

https://github.com/ReactiveX/RxJava/wiki/What's-different-in-3.0#blockingstream
Currently defined as:
Flowable, Observable, Maybe, Single, Completable

But this should be:
Flowable, Observable, Maybe, Single, Completable

[akarnokd]

@skywall Updated.

[mghildiy]

I would like to work on it.

[aleedy]

Looking to do a little a little contribution since I'm back working on a project using RxJava. Would checking some of these off be the best place to start?

[akarnokd]

These two could use the restyling:

• https://github.com/ReactiveX/RxJava/blob/3.x/docs/Conditional-and-Boolean-Operators.md
• https://github.com/ReactiveX/RxJava/blob/3.x/docs/Observable-Utility-Operators.md