I've looked around for this but haven't found what I'm looking for. I need some data to basically come pre-loaded in the app. I know that I could just put it all in on the first launch but would like to stay away from a long load time on the first launch and have it already loaded.
Is it possible to insert entities into core-data so that they are hard-coded in?
Yeah, you include a a pre-filled data store in your app bundle and copy it from the bundle to the documents directory as part of the app launch process - check if the data store exists and, if not, do the copy. You do this prior to accessing the Core Data stack for the first time.
There are a few ways you could do this. The lazy programmer way is to enter your default data into the app, either on the phone or in the simulator, grab the data store file, and include it in your Xcode project. The downside is it doesn't work well if you need to go back and edit the data model later.
The other option is to create an editor app on the Mac that uses the same Core Data model as your iPhone app (they're compatible) and edit the data in your Mac app. Jeff Lamarche talks a bit about this in one of his blog postings. I've done something similar, except I wrote a command line tool to download the latest data from a web site (in my case, XML data) and parse the XML into NSManagedObjects.
This StackOverflow post talks about a bit more complex option of having two data stores - one for your system data and one for your user data - and letting Core Data use both stores at runtime.
Related
I need to make my app such that
the first screen will have the option : NEW and SEARCH.
2.Clicking NEW should allow the user to create a new profile,
3.but clicking search should allow to access one of the stored profiles by searching for the user number.
These profiles will actually be some data about the person, his name etc. and then yes/no answers to some questions.
At the moment my app works such that I can type in my name, and do the yes/no checks and I am using plists to save the info. this means that when the I start the app the next time the app loads with the saved info. So I have got half the task done.
Now how do I make it multi-user capable so that it has the option of creating a new file or providing a search option to access existing data?
also, I am creating the plist in application directory, using the code on apple's website, but I have no clue how to access these files directly..is it possible to access these files, if I want to show the information on a desktop? Thanks.
The key phrase you want for searching Apple's docs is: Data Management.
Specifically, I would recommend the Data Management Starting Point.
Handling data can be as simple as writing a string or array to disk or as complex as a big Core Data data model. If you plan on writing and maintaining several Apple API apps, I strongly recommend eventually learning Core Data.
I hope all of you have had a good Christmas :-)
In my app i have a database, using Core Data, that requires a lot of data, at least 1.500 records consisting of 6 fields. That means at least 9.000 lines of data. All data is pure text.
During the development phase i have 250 records to test on.
The way i do populate the DB at this point is that i have a text (.txt) file, which i edit in Word and then reads into my database. This is very inconvenient for many reasons such as if i save it, by mistake, in the wrong format it all screws up (i have Swedish characters that changes).
Given the amount of records i will need i would like to ask for advice how people do these things and what to use? Is there some sort of (free) database available that i could use etc.
Cheers
For editing use notepad, notepad++, or gedit. You won't have issues with MS Word specific characters.
I am not too familiar with Core Data, but I believe it uses SQlite on the backend.
I have implemented SQLite directly into a few developments that I have worked on. It might be worth your time to take a look.
Can you give more details about your app? Platform, how often data is accessed, how often it is modified, etc.
Hmm, one way to get started on this might be to fill the Core Data store a single time, and then, whenever you need to run your tests, just copy this store file out of your application bundle into your documents directory. I maintain a "Reset All" function in a game I've worked on using this method, and it works great for very quickly populating Core Data.
Hej,
currently I am developing an app with very similar requirements - a prepopulated Core Data database with 1200+ entries with more or less the same amount of fields.
The data I receive is in xml format. I've written a small mac app which features the same core data model as the iphone app does - it will read the xml and create core data entries accordingly. I then take the database file my mac app created and add it to my iphone apps bundle, from where it will be copied to the documents folder on the first launch (or whenever a reset to the factory data is required).
This is working perfectly, I think you could do something very similar. The only difference would be that, instead of parsing xml, you'd need to write something that reads your textfile. Fear not, it's easy to do!
I've taken the approach to add a unit test that determines if the database exists. If the database doesn't exist, the test creates it from a text file (usually a plist or csv).
This approach enables me to: alter the underlying data via text, "clean" the database by simply deleting it, and run tests against the data. Since you're using CoreData, there might be some additional benefits by ensuring your schema matches the dataset; I once found I'd accidentally set an attribute to not allow nil.
So I have a question about the ideal setup for an app I am getting ready to build. The app is basically going to be a memorization tool and I already have an sqlite database full of content that I will be using for the app.
The user will navigate through the contents of the database(using the uipickerview), and select something for memorization. If that row or cell of data is selected, it is put into a pool or a uitableview that is dedicated to showing which items you have in your "need to memorize" pool. When you go to that tableview, you can select the row, and the actual data would be populated. All information in the tableview would be deletable, in the event that they don't want it there anymore...
Thats it.
I know that with database interfacing, there are a few different options out there, in this particular setup, is core data the easiest approach? Is there any other way that would be better? I am just kind of looking for a point in the right direction, any help is greatly appreciated!!
Core Data is going to be the easiest. You will want to migrate your data from your raw SQLite file to a Core Data generated SQLite file as Core Data is designed to manage its own file 100%. Fortunately you can do this with a quick command line app on the desktop and then copy the resulting Core Data Sqlite file into your application bundle for later use on iOS.
Doing raw SQLite on iOS is possible but a real headache to get right compared to the ease of use that Core Data offers.
Update
Core Data on iOS produces identical files to Core Data on the Desktop. Therefore you can develop a quick and easy app for the desktop that say for example takes the following inputs:
Table/Entity Name
CSV of a row of data
Then it would create a Core Data entity based on the entity name and insert the data into that row.
With that in place it would be trivial to do a bash script to loop through the all of the tables and the rows in those tables to create your new SQLite file.
Hmmm, might have to do a blog post some time on CIMGF about this :)
I have a Core Data based application that stores hierarchal data displayed using a series of UITableViews. To illustrate my app functionality to the user I would like to pre-populate my database/app with some dummy values. This data would be available upon installation on the user's iPhone/iPod Touch.
What is the best way to achieve this?
Create the data and include it in the app bundle. On first launch, copy that sqlite file to the documents directory and then stand up the core data stack afterwards.
Personally i would create a desktop app using the same model to do the initial data entry to make it easier on you. From there take the sqlite file that is generated and include it in your appilcation.
I'm doing an iPhone application. In this app, I just want to have a database to be used as a looked up table for values in my app. The only thing the database will do was to supply me the values I needed depending on the query of the program. It won't do any addition or deletion in the database. My question was how do I initialize a default data on the application using CoreData. So that when the program starts It already had all the values needed.
If you have other suggestions of what is better do or what are other alternatives, please tell me.
Thanks.
I would create a simple Mac application, starting from the template for a Core Data document-based application. Copy your existing .xcdatamodel over the default one in the project (or add the new data model and be sure to rename anywhere that refers to the default model). Open up the XIB file for the document window in Interface Builder and drag the Core Data Entity item into it from the Interface Builder library inspector. From the resulting dialog, choose an entity to display and select an interface to display it in.
What this will do is create a fully functional interface for adding, removing, or editing the properties of that entity type. Everything should be hooked up via Cocoa Bindings so that you don't need to write a line of code for this to work. You can add interfaces for each entity type in your model this way.
This will let you quickly enter and edit data within a Core Data document, which you can then save out to disk and add as a resource to your iPhone application. The SQLite database structures are fully compatible between the desktop and iPhone Core Data implementations, so I've found that this is a quick and easy way of testing your iPhone Core Data code.
Please refer to the Core Data Programming Guide, or see below (copy from the PG):
"
How do I initialize a store with default data?
There are two issues here: creating the data, and ensuring the data is imported only once.
There are several ways to create the data.
You can create a separate persistent store that contains the default
data and include the store as an application resource. When you want
to use it, you must either copy the whole store to a suitable
location, or copy the objects from the defaults store to an existing
store. For small datasets, you can create the managed objects
directly in code.
You can create a property list—or some other file-based
representation—of the data, and store it as an application resource.
When you want to use it, you must open the file and parse the
representation to create managed objects.
You should not use this technique on iOS, and only if absolutely necessary on Mac OS X. Parsing a file to create a store incurs unnecessary overhead. It is much better to create a Core Data store yourself offline and use it directly in your application.
There are also several ways to ensure that the defaults are imported only once:
If you are using iOS or creating a non-document-based application for
Mac OS X, you can add a check on application launch to determine
whether a file exists at the location you specify for the
application’s store. If it doesn't, you need to import the data. For
an iOS-based example, see CoreDataBooks .
If you are creating a document-based application using NSPersistentDocument, you initialize
the defaults in initWithType:error:.
If there is a possibility that the store (hence file) might be
created but the data not imported, then you can add a metadata flag
to the store. You can check the metadata (using
metadataForPersistentStoreWithURL:error:) more efficiently than
executing a fetch (and it does not require you to hard code any
default data values).
"
As mentioned above, generally we need to create a pre-populated default store with code, then use it as a
resource file, and copy it from resource bundle to document directory if the coredata file is missing. Please search the CoreDataBooks code example in your Xcode Organizer (or Apple Developer Center), and look at the - (NSPersistentStoreCoordinator *)persistentStoreCoordinator method.
I racked my brain for hours attempting to solve this. What I came up with was simply not to save the database. That way, it will be initialized each time the app is opened. If you save it, it will continue to duplicate.
I would write a tool that populates a database with the data you want in it, generate the db at build time and stuff it in your resources folder. If you are not going to write to it you can just leave it there and access it directly, if you ever did want to write to it you would need to copy it somewhere you are allowed to write (like the documents folder).