As part of an Adobe Flex application, I am writing an android native extension to allow me to send emails with file attachments using files generated from flex code. However I don't want the file to be world readable as it might contain sensitive data. Therefore I want to send the file from within my app's internal storage area / cache. I am using Intents to communicate with other apps (such as Gmail) to send the email.
After doing some research, I discovered that the functionality of FileProviders should do exactly what I want. However the static method **FileProvider.getUriForFile()** is silently failing / crashing the native extension. The native extension stops and returns null with no errors or output from LogCat.
If I manually create the Uri by parsing a string, Gmail complains that it can't attach the file to the email, and the email is sent with no attachment.
Code in FREObject call():
//... (Deal with params from flex app) ...
//Setup Intent, and attach email data send from flex application:
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("message/rfc822");
intent.putExtra(Intent.EXTRA_EMAIL, toArray);
intent.putExtra(Intent.EXTRA_CC, ccArray);
intent.putExtra(Intent.EXTRA_BCC, bccArray);
intent.putExtra(Intent.EXTRA_SUBJECT, subject);
intent.putExtra(Intent.EXTRA_TEXT, message);
Log.d("emaildebug", filePath);
//Check we can read our email attachment from flex app
//filePath is a temporary cache location.
File appFile = new File(filePath);
if (appFile.exists() && appFile.canRead()) {
Log.d("emaildebug", "file successfully read");
} else {
return null;
}
//Get a handle on the android Context instead of FREContext.
Context androidContext = (Context) context.getActivity();
//Get the location of the root files directory.
File attachPath = androidContext.getFilesDir();
File attachFile = new File(attachPath, "attachment.pdf");
//Copy file to root of files directory, so that our FileProvider can access it.
try {
copyFileUsingChannel(appFile, attachFile);
} catch (Exception e) {
Log.d("emaildebug", e.getMessage());
}
Log.d("emaildebug", "attachFile exists: " + attachFile.exists() );
Log.d("emaildebug", "attachFile path: " + attachFile.getAbsolutePath());
//This line will silently crash the native extension, instantly returning null, even in try catch.
//Uri contentUri = FileProvider.getUriForFile(androidContext, "com.example.androidextensiontest.provider", attachFile);
//Therefore manually create the Uri from a string.
Uri contentUri = Uri.parse("content://com.example.androidextensiontest.provider/files/attachment.pdf");
Log.d("emaildebug", "uri created");
Log.d("emaildebug", contentUri.toString());
//Grant permisions for all apps that can handle given intent
//Courtesy of: http://stackoverflow.com/questions/18249007/how-to-use-support-fileprovider-for-sharing-content-to-o...
List<ResolveInfo> resInfoList = androidContext.getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
for (ResolveInfo resolveInfo : resInfoList) {
String packageName = resolveInfo.activityInfo.packageName;
Log.d("emaildebug", "package: " + packageName);
androidContext.grantUriPermission(packageName, contentUri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
}
intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
intent.putExtra(Intent.EXTRA_STREAM, contentUri);
context.getActivity().startActivity(Intent.createChooser(intent, "Send mail using..."));
In Manifest File:
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="com.example.androidextensiontest.provider"
android:exported="false"
android:grantUriPermissions="true" >
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/my_paths" />
</provider>
**In my_paths.xml:**
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<files-path name="files" path="." />
</paths>
LogCat output:
11-01 10:58:09.971: D/emaildebug(17013): /data/data/air.com.example.MyAppName.debug/cache/FlashTmp.V17013/attachment.pdf
11-01 10:58:09.971: D/emaildebug(17013): file successfully read
11-01 10:58:09.991: D/emaildebug(17013): attachFile exists: true
11-01 10:58:09.991: D/emaildebug(17013): attachFile path: /data/data/air.com.example.MyAppName.debug/files/attachment.pdf
11-01 10:58:09.991: D/emaildebug(17013): uri created
11-01 10:58:09.991: D/emaildebug(17013): content://com.example.androidextensiontest.provider/files/attachment.pdf
11-01 10:58:09.991: D/emaildebug(17013): package: com.android.email
11-01 10:58:09.991: D/emaildebug(17013): package: com.google.android.gm
If I attempt to send the file from external storage using a file:// Uri, the file attachment works perfectly. However as previously mentioned the file attachment potentially contains sensitive data, therefore I wish to avoid using external storage.
What I believe I'm seeing is that FileProviders do not work within native extensions. I tried also using a ContentProvider, however neither the Constructor nor onCreate methods were called.
ContentProvider Manifest:
<provider
android:name="com.example.androidextensiontest.provider.MyContentProvider"
android:authorities="com.example.androidextensiontest.provider">
</provider>
MyContentProvider:
public class MyContentProvider extends ContentProvider implements PipeDataWriter<InputStream> {
public MyContentProvider() {
// Never Output
Log.d("emaildebug", "Constructor");
}
@Override
public boolean onCreate() {
// Never Output
Log.d("emaildebug", "OnCreate");
return false;
}
//.. Rest of class
}
Am I doing something wrong or are ContentProviders / FileProviders just not supported within flex native extensions? Alternatively, are there any other solutions for attaching a file located in internal storage to an email. My searching on Stack Overflow and google has not encountered anyone else having similar experiences, especially regarding FileProvider.getUriForFile(). Any help / comments appreciated.
Sorry for the wall of text, I wanted to record everything I've tried so far, and what works and what doesn't.
tldr; Do ContentProviders / File Providers work in flex native extensions? Are there any other methods of sending internal files as email attachments?
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