How to add an explicit declaration in gradle android

Question

compile "com.google.firebase:firebase-auth:$FOO"
compile "com.google.android.gms:play-services-auth:$FOO"

compile "com.android.support:design:$BAR"
compile "com.android.support:customtabs:$BAR"
compile "com.android.support:cardview-v7:$BAR"

I need to add explicit compilation declarations in the build.gradle file. This link says https://github.com/firebase/FirebaseUI-Android#installation so that these codes avoid conflicts. but Android studio says that FOO, BAR was not found. help me

Answer 1

FOOand BAR- these are just the variables defined in the file .gradle.
You can call them whatever you want.

To use this kind of syntax, you can define build.gradlesomething like:

project.ext { 
    firebaseVersion = '11.2.0'
    supportLibraryVersion = '26.0.1'
}

build.gradle, , .

:

dependencies {
    compile "com.android.support:design:$supportLibraryVersion"
    compile "com.google.android.gms:play-services-auth:$firebaseVersion"
}

, FOO BAR

project.ext { 
        FOO = '11.2.0'
        BAR = '26.0.1'
    }

 dependencies {
        compile "com.android.support:design:$BAR"
        compile "com.google.android.gms:play-services-auth:$FOO"
    }

Answer 2

constants.gradle

.gradle

project.ext {
    compileSdk = 26
    targetSdk = 26
    minSdk = 14

    buildTools = '26.0.1' 
    firebaseVersion = '11.2.0'
    supportLibraryVersion = '26.0.1'
    playServiesVersion = '11.2.0'
}

constants.gradle

apply from: 'constants.gradle' 

build.gradle .

// Top-level build file where you can add configuration options common to all sub-projects/modules.
apply from: 'constants.gradle'

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'
        classpath 'com.google.gms:google-services:3.1.0'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}