Kotlin - Define variable globally for WebView

Question

I'm trying to define a variable globally which is of the class WebView. In Android Java it could be easy done by writing the it

Java for global variable

 < ClassName > < variableName >

But in Kotlin I'm facing issue with its declaration.

class MainActivity : AppCompatActivity() {

var mywebview : WebView //<- This shows Property must be initialized or be abstract



override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
}

override fun onStart() {
    super.onStart()

    mywebview = findViewById(R.id.webViewGyrix) as WebView

    mywebview.setWebViewClient(object : WebViewClient() {
        override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {
            view?.loadUrl(url);
            return true
        }
    } )
    mywebview.loadUrl("http://www.example.com/")
}

Bruno Wieczorek · Accepted Answer · 2017-04-20 15:27:26Z

30

You can use late initialization - you don't have to make WebView nullable

lateinit var webView: WebView

answered Apr 20, 2017 at 15:27

Bruno Wieczorek

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3 Comments

RobCo Over a year ago

This is much better than accepted answer. Just don't access it before assigning it.

Prateekro Over a year ago

@RobCo it says Expecting member declaration

Prateekro Over a year ago

Also, This shows Property must be initialized or be abstract

Marcin Orlowski · Accepted Answer · 2018-09-17 09:26:32Z

22

This shows Property must be initialized or be abstract

Then initialize it i.e. to null. This is not a final value and you will be able to change it later:

var mywebview : WebView? = null

Alternatively, you can use lateinit feature of Kotlin, which would let you prevent having nullable mywebview if not needed:

lateinit var webView: WebView

edited Sep 17, 2018 at 9:26

answered Apr 20, 2017 at 13:56

Marcin Orlowski

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2 Comments

Prateekro Over a year ago

it shows: Null can not be a value of a non-null type WebView

Prateekro Over a year ago

Why cant we use lateinit here?

Big Zak · Accepted Answer · 2017-08-12 19:55:38Z

0

for a global variable, this means it shouldn't be overridden accidentally , so you should instead lazyload it using kotlin's lazy which create the variable on the first call, other calls will just reference the lazy loaded variable

private val webview:WebView by lazy{
  findViewById<WebView>(R.id.webview)
}

That should come before the onCreate method

answered Aug 12, 2017 at 19:55

Big Zak

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Comments

Android01 · Accepted Answer · 2017-09-25 03:45:48Z

0

Below code worked for me:

val mywebviewURL = "https://www.google.com"

  override fun onStart() {
    super.onStart()

    events_webview.setWebViewClient(object : WebViewClient() {
        override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {
            view?.loadUrl(url);
            return true
        }
    })
    events_webview.loadUrl(mywebviewURL)
}

Add internet permission to AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET"/>

answered Sep 25, 2017 at 3:45

Android01

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