I save XML file in Resources folder in xcode. And I parse it when application launches and use it for a default data set. I don't see any problem with this but people are talking about CoreData to handle a default data set. Can I just still use XML file for a default data? what is the disadvantage of using XML for default data set?
I'd say you're fine using an XML file, assuming that the data is small and you're not modifying it a lot. I use a CSV file for a couple of my apps and that's worked fine for me.
With that said, here are better answers to a similar question: Plist vs SQLite vs Core Data for a rss reader type application?
Related
I have Excel file with table ~100x100 and need to get access to this values from iOS app.
At first, I've try to make json in Mr.DataConverter and then it's not a problem to read to array. But! Some float values didn't recognized properly, and I'd got numbers without quotes:
At the time other parsed correctly!
So, from this moment I can't parse my Json string to NSArray.
The question is:
How to convert xls to json, OR How to put and retrieve the values in iOS device?
Thanks.
You can use the DHlibxls iOS Framework and simply pull the .xls file into your app, then read and process with that framework. The framework is based on the open source libxls library on SourceForge, and has a non-attributed BSD license.
I recommend exporting the Excel spreadsheet to CSV and then using a proper CSV parser to parse the data. If you run into any issues then there is likely an issue in the spreadsheet that you would need to fix.
Alternative: If possible use excel file in formate: tab delimited-text-file. That solve all your problem. Easy to open text file in iOS with file manager/c++.
convert-an-excel-spreadsheet-to-a-tab-delimited-text-file
I have read that this works, but I can't get it to. I want to pre populate Core Data. I ran my project so it would create the sqlite file. I copied that to my desktop and then prepopulated it using the command line, sqlite3. I ran queries to make sure it was populated correctly. So now I re-add it to my project. No matter what I do, though, it won't fetch the data.
I got it to work ONCE. I re-copied the sqlite file from my project's document folder after running it in the simulator. I then populated this new sqlite file. I put it back in my project and I got the contents to display.
I think the problem is the Z_METADATA table. This table has a Z_UUID attribute. I think the only time it worked was when the simulator's UUID and the sqlite's Z_UUID attribute were the same.
I went into ~/Library/Developer/Xcode/DerivedData and deleted the contents of the DerivedData folder. So now my simulator will have a different UUID when I run it. I did this and now the contents of the sqlite file will not display. This is why I think the Z_METADATA table is the problem. The Z_METADATA's UUID and my simulator's UUID are not the same so for some reason it can't use it?
All the articles about pre populating Core Data this way I found are old, around 2009, so I don't think this was a problem then. So can I use this method of copying the sqlite file, using the command line to pre populate it, then re-adding it to the project? Does anyone have a current way to prepopulate Core Data?
So the error is that my NSFetchedResultsController is returning a count of 0 objects. I got it to return all the data the one time I mentioned above.
According to the Core Data Programming Guide,
Important Although Core Data supports SQLite as a store type, the store format—like those of the other native Core Data stores—is private. You cannot create a SQLite database using native SQLite API and use it directly with Core Data (nor should you manipulate an existing Core Data SQLite store using native SQLite API). If you have an existing SQLite database, you need to import it into a Core Data store (see “Efficiently Importing Data”).
While I'm sure someone has reverse-engineered the Core Data sqlite format, Apple does not provide any documentation, and it is likely to change across across major OS releases.
Write a command-line app that uses Core Data to do your import.
Can someone help me find where CoreData is storing the SQL file it creates in iOS applications?
So far I've tried "Show package contents" on the .xcdatamodel file and also the .xcodeproj file...No dice!
Is there an editor for looking at the contents of these SQL files?
Cheers.
-A
The url parameter of [NSPersistentStoreCoordinator addPersistentStoreWithType:configuration:url:options:error] specifies the location of the file. Find this call in your code and see where you've stored it. XCode templates will put it into the top of your application documents directory, but you can put it anywhere you like.
Note that Apple considers the contents of this database to be opaque and non-user-modifiable. Playing with the data in your store is likely to cause issues with Core Data.
It's typically saved into your application's documents directory, with the name of your data model.
So, for example, if my data model is called AppData.xcdatamodeld, it will be AppData.sqlite inside my app's document directory. You shouldn't really need to touch the .sqlite file though.
Hope that helps!
Core Data editor --> http://christian-kienle.de/CoreDataEditor/
I'm using an NSXMLParser to read data out of a XML, but how can I make my iPhone App storing data into this specific XML.
The case is that I want to create an app to display available dates and one that administrates this dates, whether they are available or not (I'm using an UISwitch to handle this).
Thanks for your answers,
btype.
If you have small amount of data, you can save them in a plist.
See Property List Programming Guide
There's a github project that let's you create XML DOM objects. You can save your XML to your documents folder on the phone.
https://github.com/arashpayan/apxml/
i am working on an application that displays read-only data i am shipping.
it is more of a book.
It is easy with SQLite but i am not satisfied with the performance and trying to use Core Data.
The issue is with pre-filling Core Data is that it is a hard process.
My question is:
Is it possible to build an assistant iphone application (for me to use) which uses the same data model for pre-filling.
and then take the populated .xcdatamodel file and use it in my original application?
I hope this makes sense :)
Adham
I believe what you're asking is whether you can create a CoreData database upfront and copy it to the iPhone. Is that correct?
This article will help. Here's a quote:
I thus suggest the following five-step process:
Create your data in a comma-separated file, typically placing each row of data (an entity) in a row of the file and separating different columns (its attributes) by commas.
Write a standalone program and copy in your .xcdatamodel file from your main project.
Write code in your new program that parses your comma-separated file and inserts the information into a Core Data persistent store that should be identical to the persistent store in your main project.
Run the program in the Simulator
Copy your data from the Simulator's documents directory into your actual project's bundle.
It's possible, I've done it. I made a desktop application to read from a CSV file using the code here:
http://www.mac-developer-network.com/columns/coredata/may2009/
I just had to alter the way the CSV part worked, and change the model.
I copied and pasted my model from the model builder into the iPhone model. (Clicked on the "grid" area, selected all, copied)
Then I took the sqlite database the desktop app produced (found it in Application Support, in the folder for this application) and put it into the resources folder
I made some code to copy the sqlite into the documents folder on the iPhone (if it wasn't already there) at startup, in the applicationDidLaunch method. It's possible that having it in the resources folder is no good. Even though you're using the database as read only, Core Data may want to write something to it. Not sure about this though..
I used the sqlite file in the documents folder in my Core Data set up.
The desktop and iPhone Core Data sqlite file seem to be exactly the same format. You can transfer one sqlite file to another application (iPhone to iPhone too) as long as they have the same data model. In another application, I used NSXMLParser to create the Core Data sqlite file, then transferred it to another app, both on iPhone using the Simulator.
Yeah, your data source can be whatever you want it to be. The other suggestions are good ones. Create a managed object model (.xcdatamodel) identical to what you want to use in your app. Read in the data from your file, create a new instance of your managed object and populate it from the file. Then save, and dive into the bundle in the iPhone Simulator and copy it over. This has the added bonus of being in exactly the format you need, with all the helpful metadata. Copy your object model and your managed object classes and you're good to go.
Note, though, if you really intend for it to be read-only, and you're using it at install, it will be installed in your finished app's bundle (under Applications/{SIGNATURE}/Myapp.app). If you intend to edit this database or allow a user to save to it, it's a better idea to copy it to the Applications/{SIGNATURE}/Documents directory where your user database lives.