While this covers ~25 file types it is important to include support for custom file extensions/MIME types.

We need to be able to define these in tauri.conf.json for desktop/mobile so they are available to the builder in order to generate correct platform-specific metadata e.g. info.plist, AndroidManifest.xml.

these are just some default values because a mime type is required for the iOS file association to work; you can still define those manually in tauri.conf.json to support other types

Android's pathPattern has known limitations e.g. Doesn't match paths with multiple dots (e.g., file.backup.png).

• https://stackoverflow.com/questions/3400072
• https://issuetracker.google.com/issues/36983133

Workarounds:

1. Use multiple patterns

<data android:pathPattern=".*\\.png" />
<data android:pathPattern=".*\\..*\\.png" />
<data android:pathPattern=".*\\..*\\..*\\.png" />

2. Use MIME type only

<intent-filter>
    <action android:name="android.intent.action.SEND" />
    <data android:mimeType="image/png" />
    <!-- No pathPattern - rely on MIME type -->
</intent-filter>

3. Scheme + MIME Type

<intent-filter>
    <action android:name="android.intent.action.VIEW" />
    <data android:scheme="file" />
    <data android:scheme="content" />
    <data android:mimeType="image/png" />
</intent-filter

If filters are not generated properly, the only way forward is then to use a wildcard (*) filter which associates the app with all file/MIME types - this is not an ideal UX experience.

this can be accomplished by just setting a mimeType in the file association config

We are missing ACTION_VIEW e.g. user taps in file manager. Ideally, if would be good if we could define which actions we which to listen to.

From Android Docs:

BROWSABLE - The target activity allows itself to be started by a web browser to display data referenced by a link, such as an image or an e-mail message.

This is related to deep-linking not file association. Does this need to be handled differently? How will this interact with the deep-link plugin?

Tauri config has rank but this is not being used on Android.

{
  "ext": ["png"],
  "mimeType": "image/png",
  "rank": "Owner"  // ← This exists in config
}

Android can specify a priority on intent filters which is a signed integer between -1000 to 1000.

<intent-filter android:priority="1000">
    <action android:name="android.intent.action.VIEW" />
    <data android:mimeType="image/png" />
</intent-filter>

Same content RE: file extensions and standard UTIs. While this covers ~30 file types it is important to include support for custom file extensions/MIME types in tauri.conf.json.