Android Example Load HTML files from DirInternal to a WebView with UltimateWebView2 and WebViewAssetLoader

I would like to contribute to the never-ending question of how to load local HTML files into a WebView. The reason are the following recently asked questions (here and here by @Justmer Rivera ), which I found unanswered.

Therefore I would like to give an example of how the library UltimateWebView2 and the contained WebViewAssetLoader can be used to load an HTML file from DirInternal, which refers to other local resources (e.g. an image below the images folder) within the HTML source code.

I have summarized the most important parts of the solution here:

Sub Globals
    Private WebView1 As WebView

    ' from lib: WebViewExtras2 and WebViewSettings
    Private WebViewEx As WebViewExtras
    Private WebViewClient As DefaultWebViewClient
    
    ' from lib: UltimateWebView2
    Private WebViewAssetLoader1 As WebViewAssetLoader
    
End Sub

Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("Layout")
    
    ' Prepare Views
    WebViewAssetLoader1.Initialize(Application.PackageName)
    WebViewEx.Initialize(WebView1)
    WebViewClient.Initialize("WebViewClient")
    WebViewEx.SetWebViewClient(WebViewClient)
    WebViewEx.JavaScriptEnabled=True

    
    ' Copy test data
    File.MakeDir(File.DirInternal, "images")
    File.Copy(File.DirAssets, "test.html", File.DirInternal, "test.html")
    File.Copy(File.DirAssets, "test.jpg", File.Combine(File.DirInternal, "images"), "test.jpg")
End Sub

Private Sub WebViewClient_ShouldInterceptRequest(Url As String) As WebResourceResponse
    Log("URL: " &  Url)
    
    Dim Response As WebResourceResponse
    Dim ResponseReceived As WebResourceResponse

    Try
        ResponseReceived = WebViewAssetLoader1.ShouldInterceptRequest(Url)
        
        If Not(ResponseReceived = Null) And ResponseReceived.IsInitialized Then
            Response.Initialize(ResponseReceived.GetMimeType, ResponseReceived.GetEncoding, ResponseReceived.GetData)
            Return Response
        End If
    Catch
        ' In case the URL fails to load, we receive an exception here
        Log("URL not found: " & Url)
    End Try
    
    Return Null
    
End Sub

Attached you will find a working B4A example project. You will need the additional Libraries WebViewExtras2 and WebViewSettings to run it:

WebViewSettings

Hi all. Here's a new library that makes it easy to set and get various WebView WebSettings. Note that the official documentation for many of these settings is rather brief, sometimes vague or virtually non-existent! Here is an alphabetical list of all methods with a short description. I've...

www.b4x.com

WebViewExtras

Hi all. WebViewExtras is my latest library. It's a much updated version of JSInterface. WebViewExtras exposes more of the available native Android WebView methods to your B4A application: addJavascriptInterface(webView1 As WebView, interfaceName As String) Add a javascript interface to...

www.b4x.com