Android File Chooser not calling from Android Webview

Question

Its a simple WebApp with a Webview in it and there is a registration page with upload file option. trying to open file chooser when click on browse button but there is not response. i assume that there is some issue in my gradle files. please help me debug it. Here is my Code.

here is my project gradle

    buildscript {

        repositories {
            google()
            jcenter()
            mavenCentral()
        }
        dependencies {
            classpath 'com.android.tools.build:gradle:3.1.3'
            classpath 'com.google.gms:google-services:3.2.1'
        }
    }
    allprojects {
        repositories {
            google()
            jcenter()
        }
    }

    task clean(type: Delete) {
        delete rootProject.buildDir
    }

and here is my app gradle

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.androidapp.myApp"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 2
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        useLibrary 'org.apache.http.legacy'

        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support:support-v4:27.1.1'
    implementation 'com.google.firebase:firebase-invites:16.0.1'
    implementation 'com.google.firebase:firebase-messaging:17.1.0'

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.squareup.okhttp3:okhttp:3.8.0'

    implementation 'com.android.support:multidex:1.0.3'


}

apply plugin: 'com.google.gms.google-services'

Answer 1

It is not the gradle file error. You just need to provide custom WebChromeClient like below.

class MyWebChromeClient extends WebChromeClient {
    // For 3.0+ Devices (Start)
    // onActivityResult attached before constructor
    protected void openFileChooser(ValueCallback uploadMsg, String acceptType) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }


    // For Lollipop 5.0+ Devices
    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
        if (uploadMessage != null) {
            uploadMessage.onReceiveValue(null);
            uploadMessage = null;
        }

        uploadMessage = filePathCallback;

        Intent intent = fileChooserParams.createIntent();
        try {
            startActivityForResult(intent, REQUEST_SELECT_FILE);
        } catch (ActivityNotFoundException e) {
            uploadMessage = null;
            Toast.makeText(WebLink.this, "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
            return false;
        }
        return true;
    }

    //For Android 4.1 only
    protected void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
        mUploadMessage = uploadMsg;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("image/*");
        startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE);
    }

    protected void openFileChooser(ValueCallback<Uri> uploadMsg) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }
}

and it in your webview like below

webview.setWebChromeClient(new MyWebChromeClient());

some other useful stuff/variables to be declared globally.

public ValueCallback<Uri[]> uploadMessage;
private ValueCallback<Uri> mUploadMessage;
public static final int REQUEST_SELECT_FILE = 100;
private final static int FILECHOOSER_RESULTCODE = 1;

make sure you have all the read/write permissions

UPDATE

Use below lines to provide access to files from storage.

webview.getSettings().setDomStorageEnabled(true);
webview.getSettings().setAllowContentAccess(true);
webview.getSettings().setAllowFileAccess(true);

// EDIT, add this line also
webview.getSettings().setJavaScriptEnabled(true);

UPDATE 2

Get the result in onActivityResult method. You can use the result given like below.

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        if (requestCode == REQUEST_SELECT_FILE) {
            if (uploadMessage == null)
                return;
            uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, intent));
            uploadMessage = null;
        }
    } else if (requestCode == FILECHOOSER_RESULTCODE) {
        if (null == mUploadMessage)
            return;
        // Use MainActivity.RESULT_OK if you're implementing WebView inside Fragment
        // Use RESULT_OK only if you're implementing WebView inside an Activity
        Uri result = intent == null || resultCode != WebLink.RESULT_OK ? null : intent.getData();
        mUploadMessage.onReceiveValue(result);
        mUploadMessage = null;
    } else
        Toast.makeText(WebLink.this, "Failed to Upload Image", Toast.LENGTH_LONG).show();
}