(#) Data tags should only declare unique attributes !!! WARNING: Data tags should only declare unique attributes This is a warning. Id : `IntentFilterUniqueDataAttributes` Summary : Data tags should only declare unique attributes Severity : Warning Category : Correctness Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : 7.1.0 (January 2022) Affects : Manifest files Editing : This check runs on the fly in the IDE editor See : https://developer.android.com/guide/components/intents-filters Implementation : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/AppLinksValidDetector.kt) Tests : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/AppLinksValidDetectorTest.kt) `` `` tags should only declare a single unique attribute (i.e. scheme OR host, but not both). This better matches the runtime behavior of intent filters, as they combine all of the declared data attributes into a single matcher which is allowed to handle any combination across attribute types. For example, the following two `` declarations are the same: ```xml ``` ```xml ``` They both handle all of the following: * http://example.com * https://example.com * http://example.org * https://example.org The second one better communicates the combining behavior and is clearer to an external reader that one should not rely on the scheme/host being self contained. It is not obvious in the first that http://example.org is also matched, which can lead to confusion (or incorrect behavior) with a more complex set of schemes/hosts. Note that this does not apply to host + port, as those must be declared in the same `` tag and are only associated with each other. !!! Tip This lint check has an associated quickfix available in the IDE. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text AndroidManifest.xml:5:Warning: Consider splitting data tag into multiple tags with individual attributes to avoid confusion [IntentFilterUniqueDataAttributes] <data alt-android:scheme="https" alt-android:host="example.com"/> ----------------------------------------------------------------- AndroidManifest.xml:6:Warning: Consider splitting data tag into multiple tags with individual attributes to avoid confusion [IntentFilterUniqueDataAttributes] <data alt-android:scheme="http" alt-android:host="example.org"/> ---------------------------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `AndroidManifest.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <manifest xmlns:alt-android="http://schemas.android.com/apk/res/android" package="com.example.helloworld" > <activity alt-android:name="com.example.Activity"> <intent-filter> <data alt-android:scheme="https" alt-android:host="example.com"/> <data alt-android:scheme="http" alt-android:host="example.org"/> </intent-filter> </activity> </manifest> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/AppLinksValidDetectorTest.kt) for the unit tests for this check to see additional scenarios. (##) Suppressing You can suppress false positives using one of the following mechanisms: * Adding the suppression attribute `tools:ignore="IntentFilterUniqueDataAttributes"` 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"?> <manifest xmlns:tools="http://schemas.android.com/tools"> ... <activity tools:ignore="IntentFilterUniqueDataAttributes" .../> ... </manifest> ``` * 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="IntentFilterUniqueDataAttributes" 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 'IntentFilterUniqueDataAttributes' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore IntentFilterUniqueDataAttributes ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).