delegate

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Delegate

Some custom implementations for delegated properties

Usage

Add into your project

build.gradle

First you need to add Kotlin and the androidx core components

// Module build.gradle.kts
apply plugin: 'kotlin-android'

dependencies{
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$versions.kotlin"
    implementation "androidx.annotation:annotation:$versions.androidx.annotation"
    implementation "androidx.appcompat:appcompat:$versions.androidx.appcompat"
    implementation "androidx.recyclerview:recyclerview:$versions.androidx.recyclerview"
}

Then add the Delegate dependency

implementation "io.github.matheus-corregiari:delegate:$latest_version"

or

api "io.github.matheus-corregiari:delegate:$latest_version"

How to use

ViewProvider

class YourView : AppCompatActivity() {
    
    // Required Views (throws exception when not found)
    private val view: View by viewProvider(R.id.view_id)
    // or
    private val view: View by viewProvider(R.id.view_id, parentId= R.id.parent_view_id)

    // Optional Views accept only nullable references \o/
    private val view: View? by optionalViewProvider(R.id.view_id)
    // or
    private val view: View? by optionalViewProvider(R.id.view_id, parentId= R.id.parent_view_id)
    
}

// Also works with
class YourView : Fragment()
class YourView : View()
class YourView : RecyclerView.ViewHolder()

BIG NOTE: like another strategies to use some view binding, you need to use the references below the layout inflate... otherwise your app will crash

• AppCompatActivity -> after the inflate
• Fragment -> It's recommend to call your view on any method after onCreateView and before onDestroyView ... also after the inflate
• View -> after the inflate
• RecyclerView.ViewHolder -> after the inflate

ExtraProvider

class YourView : AppCompatActivity() {
    
    // Required Views (throws exception when not found)
    private val extra: String? by extraProvider("EXTRA_KEY")
    
    // keepState FALSE means that the delegate will call getExtra every time! TRUE means that the delegate will lazily keeps a reference extracted from getExtra
    private val extra: String? by extraProvider("EXTRA_KEY", keepState=true)

    // default value to make your extra type non null \o/
    private val extra: String by extraProvider("EXTRA_KEY", keepState=true, default="default value")

    // is you want to execute a block to build the default value
    private val extra: String by extraProvider("EXTRA_KEY", keepState=true) { "default value" }

    // You can also set this variables with var but it only works with delegates with keepState attribute set to TRUE (default value)
    private var extra: String? by extraProvider("EXTRA_KEY")
    
}

// Also works with
class YourView : Fragment()