(#) A should not be attached to an destination !!! WARNING: A should not be attached to an destination This is a warning. Id : `DeepLinkInActivityDestination` Summary : A should not be attached to an destination Severity : Warning Category : Correctness Platform : Android Vendor : Android Open Source Project Identifier : androidx.navigation.runtime Feedback : https://issuetracker.google.com/issues/new?component=409828 Min : Lint 8.0 and 8.1 Compiled : Lint 8.7+ Artifact : [androidx.navigation:navigation-runtime](androidx_navigation_navigation-runtime.md.html) Since : 2.5.0 Affects : Resource files Editing : This check runs on the fly in the IDE editor Implementation : [Source Code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/navigation/navigation-runtime-lint/src/main/java/androidx/navigation/runtime/lint/DeepLinkInActivityDestinationDetector.kt) Tests : [Source Code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/navigation/navigation-runtime-lint/src/test/java/androidx/navigation/runtime/lint/DeepLinkInActivityDestinationDetectorTest.kt) Copyright Year : 2022 Attaching a to an destination will never give the right behavior when using an implicit deep link on another app's task (where the system back should immediately take the user back to the app that triggered the deep link). Instead, attach the deep link directly to the second activity (either by manually writing the appropriate or by adding the to the start destination of a nav host in that second activity). (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text res/navigation/nav_main.xml:17:Warning: Do not attach a to an destination. Attach the deeplink directly to the second activity or the start destination of a nav host in the second activity instead. [DeepLinkInActivityDestination] <deepLink app:uri="www.example.com" /> -------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `res/navigation/nav_main.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <navigation xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/nav_main" app:startDestination="@id/fragment_main" > <fragment android:id="@+id/fragment_main" android:name="com.example.deeplink.MainFragment" /> <activity android:id="@+id/activity_deep_link" android:name="com.example.deeplink.DeepLinkActivity" > <deepLink app:uri="www.example.com" /> </activity> </navigation> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/navigation/navigation-runtime-lint/src/test/java/androidx/navigation/runtime/lint/DeepLinkInActivityDestinationDetectorTest.kt) for the unit tests for this check to see additional scenarios. The above example was automatically extracted from the first unit test found for this lint check, `DeepLinkInActivityDestinationDetector.expectFail`. To report a problem with this extracted sample, visit https://issuetracker.google.com/issues/new?component=409828. (##) Including !!! This is not a built-in check. To include it, add the below dependency to your project. ``` // build.gradle.kts implementation("androidx.navigation:navigation-runtime:2.9.0-rc01") // build.gradle implementation 'androidx.navigation:navigation-runtime:2.9.0-rc01' // build.gradle.kts with version catalogs: implementation(libs.navigation.runtime) # libs.versions.toml [versions] navigation-runtime = "2.9.0-rc01" [libraries] # For clarity and text wrapping purposes the following declaration is # shown split up across lines, but in TOML it needs to be on a single # line (see https://github.com/toml-lang/toml/issues/516) so adjust # when pasting into libs.versions.toml: navigation-runtime = { module = "androidx.navigation:navigation-runtime", version.ref = "navigation-runtime" } ``` 2.9.0-rc01 is the version this documentation was generated from; there may be newer versions available. [Additional details about androidx.navigation:navigation-runtime](androidx_navigation_navigation-runtime.md.html). (##) Suppressing You can suppress false positives using one of the following mechanisms: * Adding the suppression attribute `tools:ignore="DeepLinkInActivityDestination"` on the problematic XML element (or one of its enclosing elements). You may also need to add the following namespace declaration on the root element in the XML file if it's not already there: `xmlns:tools="http://schemas.android.com/tools"`. ```xml <?xml version="1.0" encoding="UTF-8"?> <deepLink xmlns:tools="http://schemas.android.com/tools" tools:ignore="DeepLinkInActivityDestination" ...> ... </deepLink> ``` * Using a special `lint.xml` file in the source tree which turns off the check in that folder and any sub folder. A simple file might look like this: ```xml <?xml version="1.0" encoding="UTF-8"?> <lint> <issue id="DeepLinkInActivityDestination" severity="ignore" /> </lint> ``` Instead of `ignore` you can also change the severity here, for example from `error` to `warning`. You can find additional documentation on how to filter issues by path, regular expression and so on [here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html). * In Gradle projects, using the DSL syntax to configure lint. For example, you can use something like ```gradle lintOptions { disable 'DeepLinkInActivityDestination' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore DeepLinkInActivityDestination ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).