aaverin / firekonf

Firebase Remote Config – best practices and Kotlin data classes support

FYI: Only works with Kotlin 1.2.X

Due to updates in kotlinx.serialization, library needs an update to Kotlin 1.3.X

FiReKonf – Firebase Remote Config, best practices and Kotlin support

Firebase Remote Config is very easy and straightforward to implement.

That is, until you find that you throttle the cloud and get random amounts of FirebaseRemoteConfigFetchException or FirebaseRemoteConfigFetchThrottledException.

In this YouTube video

Todd Kerpelman highlights several approaches on how to make sure users get latest data from Firebase Remote Config promptly.

This library implements #3 approach:

• Fetch and activate on first init
• Fetch, but don't activate on all other inits
• Activate previously fetched data on every init
• Support force-refetch in case of critical errors

In addition to that, thanks to kotlinx.serialization, it is now possible to write a data class, and back it by data coming from Remote Config.

Same class can be used to provide default values.

Take a look:

@Serializable
data class TestKonf(
    @SerialName("list_ads_frequency")
    val myCustomParam: Int = 0,
    val someTestParam: String = "default_value"
) 

Then in your Application class add:

override fun onCreate() {
   super.onCreate()

   val defaultsKonfig = TestKonf()
   
   fiReKonf.init(defaultsKonfig, FiReKonfOptions(isFirst = sharedPrefs.isFirst /*, forceUpdatePending = true*/))
}

And later you can simply use the data by calling

val fetchedKonfig: TestKonf = fiReKonf.get(remoteConfig)

Depending on current state of Remote Config, FiReConf will fill in data class, merging defaults with data from Remote Config

You can see more detailed example in sample folder

Installation

Install via Jitpack.io

Add it in your root build.gradle at the end of repositories:

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Add the dependency

implementation "com.github.aaverin:firekonf:1.1"

Additionally, you will need to add kotlinx.serialization to the project. Add following to the build.gradle in the root folder:

 buildscript {
    repositories {
        maven { url "https://kotlin.bintray.com/kotlinx" }
    }
 }
 
 allprojects {
     repositories {
         ...
         maven { url "https://kotlin.bintray.com/kotlinx" }
     }
 }

And following to dependencies. Please, note, that kotlinx.serialization version is tightly coupled to kotlin version. eg, for 1.2.61 you need 0.6.1

classpath "org.jetbrains.kotlinx:kotlinx-gradle-serialization-plugin:0.6.1"

Apply plugin in the app/build.gradle file:

apply plugin: 'kotlinx-serialization'

Extra

A little javascript to build a Kotlin data class from Firebase Remote Config. Source

process = () => {
    let names = $("mat-card > .parameter .content .name").map((i, e) => {
        return $(e).html()
    }).toArray()
    let descriptions = $("mat-card > .parameter .content").map((i, e) => {
        let desc = $(e).find(".description").html()
        if (desc) { return desc } else { return "" }
    }).toArray()
    let values = $("mat-card > .parameter .content .values").map((i, e) => {
        return $(e).find(".default-value .parameter-value").html()
    }).toArray()

    if (names.length != descriptions.length || names.length != values.length || descriptions.length != values.length) {
        console.log(`Critical script error, please report to author! names: ${names.length}, descriptions: ${descriptions.length}, values: ${values.length}`)
        return
    }

    let kotlinDataClass = []

    kotlinDataClass.push("@Serializable\n")
    kotlinDataClass.push("data class FiReKonf(\n")
    console.log(names)
    let structure = names.flatMap((name, index) => {
        let description = descriptions[index]
        let value = values[index]
        var fixedValue
        if (value.length > 60) {
            fixedValue = `"""${value}"""`
        } else {
            fixedValue = `"${value}"`
        }
        let result = []
        if (description) {
            result.push(`    //${description}\n`)
        }
        result.push(`    val ${name}: String = ${fixedValue}`)
        if (index != names.length - 1) {
            result.push(",\n")
        }
        return result
    })
    structure.forEach(e => {
        kotlinDataClass.push(e)
    })


    kotlinDataClass.push("\n)")

    console.log(kotlinDataClass.join(""))
}

How to use

1. Go to your Firebase Remote Config page in Chrome
2. Select Menu -> More Tools -> Developer Tools (or press Option + Shift + I on Mac / Alt + Shift + I on Windows)
3. Select Console tab
4. Paste javascript into the Console and press Enter
5. Type process() and press Enter

Resulting Kotlin data class will be printed into the output. Copy it and put into your project.

You can use @SerialName kotlinx.serialization annotation to instruct parser which name to grab from Remote Config