Persistence on an online click once application - deployment

Is there a way to persist an string from an online click once application. I saw something about isolated file storage as answers to other questions. But none of them specify if it works also for online apps (I really don't think so).
I think that something like a cookie will work. Is there something like that available?
The application must run only online (is triggered with some parameters), but for each user it needs to save a file with specific information asked to him. Once the app runs for the very first time it must not ask for that info to the user.
Thanks.

You can store the information in LocalApplicationData. Just create a directory with either your application name or your company name, stick the string in a file, and read it from there. This article shows you how to persist this data, and not have it impacted by ClickOnce updates. It will work even though your application is online-only. (Online-only C/O apps are still installed, it just means it always runs it from the URL, and requires the user to be connected in order to install the app.)

Related

How do you do continous deployment in an AJAX application with lots of client side interaction and local data?

We have an app that is written in PHP. The front end uses javascript heavily. Generally, for normal applications that require page reloads, continuous deployment is not really an issue, because:
The app can be deployed with build tags: myapp-4-3-2013-b1, myapp-4-3-2013-b2, etc.
When the user loads a page (we are using the front controller pattern), we can inject the buildtag and the files are loaded from the app directory with the correct build tag.
We do not need to keep the older builds around for too long because as the older requests finish, they will move to the newer build tags.
The issue with database and user data being incompatible is not very high as we move people to the newer builds after their requests finish (more on this later).
Now, the problem with our app is that it uses AJAX heavily for smooth page loads. In addition, because there is no page refresh at all when people navigate through the application, people can keep their unsaved data in a their current browser session and revisit it as long as the browser has not been refreshed.
This leads to bigger problems if we want to achieve continuous deployment:
We can keep the user's buildtag in their session (set when they make the first request) and only switch to newer buildtags after the logout and login again. This is obviously bad, because if things like the database schema changes or the format of files to be written to disk changes in a newer build, there is no way to reconcile this.
We force all new requests to a newer build tag, but there is a possibility we change client side javascript and will break a lot of things if we force everyone with a session onto the new build tags immediately.
Obviously, the above won't occur with every build we push and hopefully will not happen a lot, but we want to build a fool proof process so that every build which passes our tests can be deployed. At the same time, we want to make sure that every deployed and test passing build does not inadvertently break in clients with running sessions cause a whole bunch of problems.
I have done some investigation and what google does (at least in google groups) is that they push a message out to the clients to refresh the application (browser window). However, in their case, all unsaved client side data (like unsaved message, etc) would be lost.
Given that applications that uses AJAX and local data are very common these days, what are some more intelligent ways of handling this that will provide minimal disruption to users/clients?
Let me preface this that I haven't ever thought of continuous deployment before reading your post, but it does sound like quite a good idea! I've got a few examples where this would be nice.
My thoughts on solving your problem though would be to go for your first suggestion (which is cleaner), and get around the database schema changes like this:
Implement an API service layer in your application that handles the database or file access, which is outside of your build tag environment. For example, you'd have myapp-4-3-2013-b1, and db-services folders.
db-services would provide any interaction with the database with a series of versioned services. For example, registerNewUser2() or processOrder3().
When you needed to change the database schema, you'd provide a new version of that service and upgrade your build tag environment to look at the new version. You'd also provide a legacy service that handles the old schema to new schema upgrade.
For example, say you registered new users like this:
registerNewUser2(username, password, fullname) {
writeToDB(username, password, fullname);
}
And you needed to update the schema to add the user's date of birth:
registerNewUser3(username, password, fullname, dateofbirth) {
writeToDB(username, password, fullname, dateofbirth);
}
registerNewUser2(username, password, fullname) {
registerNewUser3(username, password, fullname, NULL);
}
The new build tag will be changed to call registerNewUser3(), while the previous build tag is still using registerNewUser2().
So the old build tag will continue to work, just that any new users registered will have a NULL date of birth. When an updated build tag is used, the date of birth is written to the database correctly.
You would need to update db-services immediately, as soon as you roll out the new build tag - or even before you roll out the build tag I guess.
Once you're sure that everyone is using the new version, you can just delete registerNewUser2() from the next version of db-services.
This will be quite complicated to make sure that you are correctly handling the conversion between old API and new API calls, but might be feasible if you're already handling continuous deployment.

Password login for ios app

I am currently developing an app for a company that is in a very competitive field. I have finished all of the features of the app that they requested except for one, making it somehow protected from their competing companies to download and use. I thought that I could set up a UIViewController with a password field that would check against some kind of database, but I'm not sure how to do the checking against a database part nor the practicality of it, and was hoping I could get some ideas on how to do this so that other companies couldn't steal and use this app without a password or something that changes like every 30 days or something and is kind of like an activation code.
Review the WWDC 2012 video "Building and Distributing Custom B2B Apps for iOS". I'm unsure if your app is in this B2B classification, it seems that it might be from your description.
What I ended up doing (if everyone needs a reference) was setting up a server with an SQL table that has pass codes in it. Since apple does not allow for any sort of system that requires you to "buy the app from outside the app store" I made a dumby username field (shame on me) that takes any value you like and then requires to have a pass code that fits. Once the pass code gets authenticated with the web server in a json sql request (there are plenty of api's to do this with) it comes back and sends the user to the first screen and sets a value in a plist with how many days of use the user has left. Whenever the user opens up the app it checks to see if the date is different from the last date logged in (saved in the same plist file) and if it is different then it calculates the difference and deducts that many. When the count reaches 0 it sends the user to the pass code authentication screen again. A bit complicated but an effective method of getting around Apple's restriction on not having a sort of pass code system like this. Thanks for the answers, unfortunately enterprise did not work for this company since they needed to be able to distribute the app to as many 3rd party members as they wanted to without having to worry about them leaving the company for other suppliers and remote management of the app (I.e ability to remote uninstall) was also not an option. Hope this helps someone someday!

iOS encryption to use web data securely

I'm developing an app that's pretty simple, and the important part of it is the content, which consists of lots of info that has been gathered over many years. I want to format it in a nice way to show to the user.
When the user downloads the app and first loads it, it goes to the server to get the whole database into the phone. Then, he can see the important items, and sort/filter through them. To avoid somebody taking my database, I'll use a SSL connection. I know if they want they could use the app to see every piece of content one by one, but there's nothing to do about that.
The thing is: I have the data in the cloud (mine). I can securely download it using an SSL connection (any other ideas to secure the transfer?). When I get it here, I'll save it in a db (Core Data is the obvious choice).
How can I secure the data in the internal database, so if the app is hacked, someone cannot access the db? I would put it in the keychain but it's a rather large db for that and it's not that important. (It's not sensible info, just info I don't want anybody to get massively.)
The other thing I could do is to never store anything in the device and have the user always making calls to the cloud, but I think this would be too time consuming. And just give him the option to save their favorite picks to the device. But that's too time consuming and there is the sync issue.
This is a reference I looked up about a similar issue, without the part I'm asking answered:
How to encrypt iPhone upload and download of info?
Basically, the only choice is to use SqlCipher. Of course, you have to port it to iPhone yourself (unless someone else has posted a port since last I looked). But it's not an insurmountable task.
Of course, even with SqlCipher you have the challenge of storing the key somehow. There's no really secure way to do this -- you have to use some form of "security by obscurity".
Why not just have some private key info stored in the code, and then when you want to download the database just have it query the server with the key? That way you wan't need to worry about SSL or encryption in the downloading part. In regards to storing it I agree with Hot Licks, SqlCipher appears to be the best and only option. However watch out for encryption, as you will have to declare it to apple and get all kinds of export permits (http://stackoverflow.com/questions/2135081/does-my-application-contain-encryption).
Hope this helps,
Jonathan

Way to expose appstore IDs but keep them secured for release

I am working on an application that will allow the user to purchase content from the app store
https://developer.apple.com/library/mac/#documentation/NetworkingInternet/Conceptual/StoreKitGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40008267-CH1-SW1
These products require a "ProductID" that ties them to whatever is in the appstore.
I will need to store these IDs somewhere in the application so I know what to send the server when the purchase button is clicked.
I wish to expose these ID's and allow non-programmers to enter any ID they want in both our side and the server side, and not have to call on a programmer to go into the code and change some enum.
I figured a config file would not be very secure, for in the end it's just a text file that a user could potentially view after purchasing the app. May not be a huge problem if a user saw the ID, but I don't like the idea of anybody seeing the innards that go through a payment process
Assuming im making sense here, whats a good way to expose these IDs but still keep them secure so users may not find them?
Also curious, how secure is something like an enum in c++? Can people break the .exe down and see the code and its values?
For your final question, yes and no. If they have access to the debugging information (a PDB in Microsoft land) then yes. But armed with just an exe and disassembler, you will see only the constant values that are assigned to the enum members.

Copying data from Field Test Mode

I'd like to copy out some data from the iPhone field test mode. Is there any way to do it? I'm using the data for testing, so it's not necessary to require App Store approval.
Since the field test mode is a built-in application that gathers information on the phone and its network, you can't really do anything to interact with it.
The information that the application gathers is likely taken from the private API. If there's specific information you're tying to get, I would ask a more specific question here on stackoverflow about it.