Hello Mark...

hello, Invisible

how can I help you today

?

Do you know what an * means in many Android's source xml files... Like:

android:theme="@*android:style/Theme.Holo.Dialog.Alert"

no, I don't

I know of @+id notation, but what is @*android: notation?

in fact, I don't remember ever seeing that * notation

when I use them they work with or without * char...

Hello Mark

(BTW, hello, Arif -- I will be with you shortly!)

Oh, ok then...

Invisible: sorry, but I have no clue

That was the only thing I wanted... You may answer Arif's questions...

and, unfortunately, it's one of those things that might be hard to research, given that it is punctuation... :-)

OK

Arif: do you have a question?

I have a project that needs data transmission between devices through Internet

and those data will be use to chart graph

and additionally, these data will be updated once, daily

however I'm not used with database usage nor data transmission

so what's your suggestion to tackle those problems?

um

if you are going to have a central database, then most of your work involves creating a Web service to which the devices can send data

the only Android parts would then be communicating with that Web service, and the details for how best to do that would depend almost entirely upon what sort of protocol the Web service supports (e.g., REST with JSON)

if, on the other hand, you are trying to say that you want devices to be communicating directly with each other, and somehow maintaining a database synchronized between all of them, that's a massive challenge

and I have no idea how you would even start trying to do that well

what I am trying to do is generally like this

one user enter data into his device to plot the graph

and then these data can be pushed into the cloud/database/etc

and the other user would be able to know when there is a new data available and download them to view to the graph on his own device

OK

first, you need to create your "cloud/database/etc"

that does not directly have anything to do with Android

particularly if you want to also support other platforms

your choice of "cloud/database/etc" implementation will determine how best to do the communications from the device to the "cloud/databae/etc"

in terms of "the other user would be able to know when there is a new data available", Google Cloud Messaging (GCM) is a likely solution

your cloud can send messages to relevant devices, alerting them of data changes

or, the device can simply poll periodically for changes

so will GCM be able to act as database as well?

no

GCM is a messaging service

your Web service that has a database can also use GCM to push data back down to devices

but GCM is not your Web service, and it is not a database

(BTW, Invisible, if you come up with another question, let me know)

No, I have an answer though...

It seems @*android: is a way to access private androids values...

I use:

android:layout_marginLeft="@*android:dimen/preference_fragment_padding_side"

but without the @* it halts parsing of XML with:

layout_file.xml:6: error: Error: Resource is not public. (at 'layout_marginLeft' with value '@android:dimen/preference_fragment_padding_side').

OK

Thanks Mark

as for now you've gave me a valuable insight on this stuff

if either of you have another question, go right ahead

I don't... Thank you for your service...

bye...

you are very welcome -- bye!

OK, that is a wrap for today's chat

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this chat's transcript will appear at http://commonsware.com/office-hours/ shortly

have a pleasant day!