How does my phone know what to sync?

[abhoward9]

okay so i've been flashing a few roms recently to see what i liked best, but i've been wondering, how does my device know what to sync? for example: if i flash a new rom, my contact list starts off as being empty, but it quickly syncs with my gmail account, and my contact list fills up. but when i add a new contact on my phone after that, i can look at my phone contacts in gmail, and it will appear in there. how is it that my contact list doesnt try syncing with the list on my newly flashed phone and delete all the contacts?

 

[mwhartman]

Your Google account contains your contacts and gmail. I have a Droid so my experience may be different. Tap menu, tap settings, tap accounts & sync. Tap my Gmail, tap contacts, email, and picasa.

Mike

 

[abhoward9]

Your Google account contains your contacts and gmail. I have a Droid so my experience may be different. Tap menu, tap settings, tap accounts & sync. Tap my Gmail, tap contacts, email, and picasa.

Mike

sorry, but thats really not even close to what i was asking...

here:
If I add a contact on my phone, I can go to gmail and see that it has been added there
If i go to gmail on my computer and add a contact there, it will show up on my phone
So it syncs both ways
Now, if I flash a new ROM, how is it that my phone knows to take the contacts that are in Gmail, instead of Gmail seeing that my phone has no contacts and syncing to that and deleting all my contacts?

 

[jstafford1]

When you flash the new ROM I assume you are wiping data. Therefore when you log in for the first time its loading contacts from your gmail to the phone.

When its just you adding or deleting it goes both ways but the initial login its loading from google. So anything tied to you gmail upon reactivating will get loaded when you first log in on your phone.

Sent from somewhere...

 

[mwhartman]

Sorry if I miscommunicated. Let me try again. Your contacts are associated with your Google account. When you flash a new rom you wipe your data and cache. When you reactive by reentering your google account the phone and your google account begin communicate and look and compare entries. At this point the phone has no entries, therefore, the information in google is transferred to the phone.

It is like a thermos. How does it know to keep the liquid hot or cold?

 

[abhoward9]

Ah i see, thank you for the explanation

 

[abhoward9]

Sorry if I miscommunicated. Let me try again. Your contacts are associated with your Google account. When you flash a new rom you wipe your data and cache. When you reactive by reentering your google account the phone and your google account begin communicate and look and compare entries. At this point the phone has no entries, therefore, the information in google is transferred to the phone.

It is like a thermos. How does it know to keep the liquid hot or cold?

well thermos's work because they use magic... obviously

but yea i get it now, thanks

 

[mwhartman]

Sorry if I miscommunicated. Let me try again. Your contacts are associated with your Google account. When you flash a new rom you wipe your data and cache. When you reactive by reentering your google account the phone and your google account begin communicate and look and compare entries. At this point the phone has no entries, therefore, the information in google is transferred to the phone.

It is like a thermos. How does it know to keep the liquid hot or cold?

well thermos's work because they use magic... obviously

but yea i get it now, thanks

Google uses the same magic, I think!