Android Question Contacts Changed Event

[echapeta]

I need an efficient way to be alerted when the phone's contacts are changed.

Currently, I'm reading the contacts using ContactUtils (faster) and the Phone/Contacts (to get more info/fields).

I keep a Map with the ContactID and a Hash over the fields, and periodically I check for changes.

This process is very slow and resources consuming when you have more than 1000 or 2000 contacts.

Is there any way to monitor and get an event when something changes in the Contacts ?

I need an event driven way....

Thank You.

 

[bsnqt]

I think you can use ContentObserver... If it is not possible in B4A you need to write a small library (Eclipse) using ContentObserver. Every time there is a change in Contacts, you will have an intent sent by your library with a specific action. Use BroadcastReceiver that listens for this intent (with specific action) in your B4A app. I have successfully listened to Contacts change in my app, using this solution.

It is similar to this task:
http://www.b4x.com/android/forum/threads/is-there-something-similar-to-contentobserver-in-b4a.32051/

Maybe there are better methods but I don't know. I believe experts in this forum will give you more advices.

 

[Erel]

ContentObserver can help. However it is not so simple. It will only track changes when your app is running.

You should use ContactUtils to retrieve the contacts. It shouldn't be a slow operation.

 

[echapeta]

Erel,

Yes, ContactUtils took 2 secs, but If you need more fields, you must extract them for each Contact, this is time consuming.

Also, in order to generate the Hash and compare you must go Contact per Contact.

With 2000 contacts in a S2 it takes about 1 minute,

I use B4A in order to avoid Java and the Android OS, but if there is no other way, I will try to write a Library.

Thank You.

 

[Erel]

Writing the code in Java will not help.

You do not need to get all the fields each time. Only get the IDs and names and if there is a new contact you should get its fields.

You can also do all of this asynchronously by using ContentResolver.QueryAsync instead of Query.

 

[echapeta]

Dear Erel,

I understand that in order to write a Library you need to do it in Java, at least I get this from the examples.

Yes, I get all the Contacts with CU, but anyway when you must loop in them in order to get the fields that CU doesn't provide and to generate and check the Hash, then you get into a very resources and time consuming activity.

Yes, you can do it Async or in another thread, anyway is slow and consumes resources.

As is with the available Libraries, without them, B4A would be very limited in functionality.

Thank You,

 

[Erel]

What I meant is that building a new library will not help in this case. Fetching all the data of all the contacts will always be slow. It is not slow because of B4A. It is slow because you need to send many requests to the contacts content provider.

 

[echapeta]

Dear Erel,

I partially agree.

This happens because we are using a procedural programming model.

We need to periodically scan the contacts looking for changes, and many times just to found that there are not changes.

If we could get an event fired when something changes, and better, what Contact changed, we will go to and event driven programming model, a lot more efficient....

Thank You.

 

[Erel]

You are correct that ContentObserver might be useful here. Though remember that it will only catch changes when your process is running.

 

[echapeta]

I have a service running in foreground...