I am having difficulty understanding intent filter categories. Wondering if someone can elaborate.

First, some seeming inconsistencies on Pg 145 of the book says

1. add an intent-filter tag to the component's manifest node using the following tags (though all the examples I see are within the activity node)

2. ACTION ... Each intent filter must have one and only one action tag (though the android documentation has examples all listing multiple action tags)

3. DEFAULT ... This is also necessary for Activities that are launched using an explicit intent (though the Android doc says - Therefore the DEFAULT category is required for all filters, expcet for those with the MAIN action and LAUNCHER category - intent filters are not consulted for explicit intents)

Anyway, I am having difficulty understanding DEFAULT, ALTERNATIVE, SELECTED_ALTERNATIVE, HOME (for example, I tried with no action and HOME category with SELECTED category to see if I would be asked at bootup or on clicking Home button to pick between my app and the system home screen - but nothing happened).

Thanks in advance

Some more seeming inconsistencies.

P146 says (2.1) Action matches are made if the Intent filter has no action specified, but http://developer.android.com/guide/t...s-filters.html states if the filter fails to list any actions, all intents fail the test

3 Data match: Specifying no data values in an Intent filter will result in a match with all Intent data values , but http://developer.android.com/guide/t...s-filters.html says (b, c, d) if an intent object contains a URI and / or data type, the intent filter is required to have the exact same

ok, after reading & rereading the android documentation (including menus) as well as the book, beginning to get a clearer idea on DEFAULT, ALTERNATIVE and SELECTED_ALTERNATIVE. Still not clear about how HOME works.

This chapter on Intents could definitely have more structure to the descriptions, I feel.

Anyway, on a slightly unrelated note, I was searching for what the "vnd" meant and I found a good description from way back 2007 here.

http://markmail.org/message/4qto6tizez2pyp4v