Flow-CombineTuple-KT

Flow-CombineTuple-KT contains helper functions for Flow, to combine their latest emissions into typed tuples.

Under the hood, it uses Tuples-KT to help provide combiners from 2 to 36 arity.

combineTuple(flow1, flow2, flow3) // returns Flow<Triple<A, B, C>>
    .map { (t1, t2, t3) ->
        // do something with combined Flow values
    }

There are two other convenience helpers.

val state: StateFlow<...> = combineAsState(
    viewModelScope,
    SharingStarted.WhileSubscribed(),
    flow1, 
    flow2, 
    flow3,
    flow4,
    null,
    ::Tuple4, // this can be any mapper as { a, b, c, d -> ... }
)

val state: StateFlow<...> = combineStates(
    viewModelScope,
    SharingStarted.WhileSubscribed(),
    stateFlow1, 
    stateFlow2, 
    stateFlow3,
    stateFlow4,
    ::Tuple4,  // this can be any mapper as { a, b, c, d -> ... }
)

Why?

It's useful when you want to combine multiple reactive streams together and get a combined object of the latest values, without defining an actual class with an actual name to do it.

Using Flow-CombineTuple-KT

In order to use Flow-CombineTuple-KT, you need to add jitpack to your project root build.gradle.kts (or build.gradle):

// build.gradle.kts
allprojects {
    repositories {
        // ...
        maven { setUrl("https://jitpack.io") }
    }
    // ...
}

or

// build.gradle
allprojects {
    repositories {
        // ...
        maven { url "https://jitpack.io" }
    }
    // ...
}

In newer projects, you need to also update the settings.gradle file's dependencyResolutionManagement block:

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()
        maven { url 'https://jitpack.io' }  // <--
        jcenter() // Warning: this repository is going to shut down soon
    }
}

and then, add the dependency to your module's build.gradle.kts (or build.gradle):

// build.gradle.kts
implementation("com.github.Zhuinden:flow-combinetuple-kt:1.3.0")

or

// build.gradle
implementation 'com.github.Zhuinden:flow-combinetuple-kt:1.3.0'

License

Copyright 2020-2023 Gabor Varadi

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.