Vet Your Manifest, Again
A couple of years ago, I warned you to vet the contents of your manifest. But, if you are like me, the past two years have felt like a decade. So, it’s not unreasonable to have forgotten the lessons from that blog post. Since a recent bit of news highlighted this problem again, perhaps it is time to revisit the topic.
What you ship in your app is your job to manage. That includes all the entries in the merged manifest. It does not matter whether the entries were added by you, by a library, or by a space alien 👽. If it is in your app, you own it and any problems it causes.
So, there’s this app. It is not a Web browser. However, as Kate McNamara pointed out, the app really wants to be a Web browser, offering to handle random URLs as an alternative to the user’s real browser.
The app has a splash screen, in the form of a
SplashActivity. That activity’s
manifest entry has the following
<intent-filter> <action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.BROWSABLE" /> <data android:name="http" /> </intent-filter>
If another app calls
startActivity() for a matching
Intent, and the user chooses to
have this app handle it, this app will
start up and show its
SplashActivity. However, that is a very generic
having little to do with the app or its maker.
This is not good.
Fortunately, it only honors the insecure
http scheme. 🙄
Having an activity in your app that responds to your own domain name is reasonable.
It is a key element of deep links,
for example. But the
<intent-filter> needs to be scoped to your
own site using
android:host on the
<data> element. In this case, that was not
done, to users’ detriment.
Every so often, scan through your merged manifest and ask yourself: do we need all this stuff? You might be scared by what you find in there.
And, um, don’t try to be a Web browser. Unless, y’know, you are writing a Web browser.
Learn second-generation Android app development — with Kotlin and the Android Jetpack — through CommonsWare’s Android app development training!