Gmail attachment and custom extension

Question

I work currently on an Android application that read file with a custom extension. One of the mandatory features, is that the app must be proposed by gmail when the user receive a mail with the attachment .ourextension.

I did some research, and found that gmail client on Android doesn't rely on the extension, because in the data of the launched intent the file proposed has no extension. It only rely on the mime-type given by the mail client.

The problem is that our custom file are not detected the same way between mail clients. For example, if I send to myself with the gmail webpage our custom file, the mime-type is detect as application/octet-stream. If a friend of mine send with apple mail desktop software, it is detected as a text/xml (which would be nice). And on another mail client, Evolution, the mime-type is text/plain...

Our application can't handle all those types ! Otherwise, it would be proposed for every type of attachment...

Is there any solution for this ?

Answer 1

Solution to open file with custom extension tested with gmail < 4.2, gmail 4.2, Google Drive and file browser

Code to send file :

sendIntent.setType("application/calc1");

Intent-filter :

           <!-- Filter to open file with gmail version < 4.2 -->
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:mimeType="application/calc1" />
            <data android:pathPattern=".*\\.calc1" />
            <data android:host="*" />
        </intent-filter>

        <!-- Filter to open with file browser or google drive -->
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:scheme="file" />
            <data android:mimeType="*/*" />
            <data android:pathPattern=".*\\.calc1" />
            <data android:host="*" />
        </intent-filter>

        <!-- Filter to open file with gmail version 4.2 -->
        <!-- Save file first with "save" button otherwise gmail crashes -->
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:mimeType="application/octet-stream" />
            <data android:pathPattern=".*\\.calc1" />
            <data android:host="*" />
        </intent-filter>