How to save data , in an iOS application?

Question

I am developing an application where the user creates an event which has 3 fields:

Category , name , event. After the user gives his entry , i have a save

Answer 1

For saving data via NSUserDefaults I'm using GVUserDefaults

Usage

Create a category on GVUserDefaults, add some properties in the .h file and make them @dynamic in the .m file.

// .h
@interface GVUserDefaults (Properties)
@property (nonatomic, weak) NSString *userName;
@property (nonatomic, weak) NSNumber *userId;
@property (nonatomic) NSInteger integerValue;
@property (nonatomic) BOOL boolValue;
@property (nonatomic) float floatValue;
@end

---

// .m
@implementation GVUserDefaults (Properties)
@dynamic userName;
@dynamic userId;
@dynamic integerValue;
@dynamic boolValue;
@dynamic floatValue;
@end

Now, instead of using [[NSUserDefaults standardUserDefaults] objectForKey:@"userName"], you can simply use [GVUserDefaults standardUserDefaults].userName.

You can even save defaults by setting the property:

[GVUserDefaults standardUserDefaults].userName = @"myusername";

Answer 2

You can use core data to save all your data and delete it when you want. The code above always create new object of Note class so every time new data you have but when you will try to write with the same name "Note". It always overwrite the old data.

Answer 3

All are correct besides that you can use Sqlite to save the data locally with your application.

This is just a file but accepts all standard sql statements.

This is also one way to save the data locally..

Answer 4

Try

//Note.h 

#define kNoteCategory  @"Category"
#define kNoteName      @"Name"
#define kNoteEvent     @"Event"

@interface Note : NSObject

@property (nonatomic, copy) NSString *category;
@property (nonatomic, copy) NSString *name;
@property (nonatomic, copy) NSString *event;

- (id)initWithDictionary:(NSDictionary *)dictionary;

+ (NSArray *)savedNotes;
- (void)save;

//Note.m file

- (id)initWithDictionary:(NSDictionary *)dictionary
{
    self = [super init];
    if (self)
    {
        self.category = dictionary[kNoteCategory];
        self.name = dictionary[kNoteName];
        self.event = dictionary[kNoteEvent];
    }

    return self;
}

+ (NSString *)userNotesDocumentPath
{
    NSString *documentsPath  = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0] stringByAppendingPathComponent:@"UserNotes.plist"];

    return documentsPath;

}

+ (NSArray *)savedNotes
{
    NSString *documentsPath = [self userNotesDocumentPath];
    NSArray *savedNotes = [NSArray arrayWithContentsOfFile:documentsPath];
    NSMutableArray *savedUserNotes = [@[] mutableCopy];
    for (NSDictionary *dict in savedNotes) {
        Note *note = [[Note alloc]initWithDictionary:dict];
        [savedUserNotes addObject:note];
    }

    return savedUserNotes;

}

- (NSDictionary *)userNoteDictionary
{
    NSMutableDictionary *dict = [NSMutableDictionary dictionary];

    if (self.category) {
        dict[kNoteCategory] = self.category;
    }
    if (self.name) {
        dict[kNoteName] = self.name;
    }
    if (self.event) {
        dict[kNoteEvent] = self.event;
    }

    return dict;
}

- (void)saveUserNotesToPlist:(NSArray *)userNotes
{
    NSMutableArray *mutableUserNotes = [@[] mutableCopy];
    for (Note *note in userNotes) {
        NSDictionary *dict = [note userNoteDictionary];
        [mutableUserNotes addObject:dict];
    }
    NSString *documentsPath  = [Note userNotesDocumentPath];
    [mutableUserNotes writeToFile:documentsPath atomically:YES];
}

#pragma mark - Save

- (void)save
{
    NSMutableArray *savedNotes = [[Note savedNotes] mutableCopy];
    [savedNotes addObject:self];
    [self saveUserNotesToPlist:savedNotes];
}

Save a note by

- (IBAction)save:(id)sender {

    //creating a new "note" object
    Note *newNote = [[Note alloc]init];

    newNote.category = categoryField.text;
    newNote.name = nameField.text;
    newNote.event = eventField.text;

    //Saves the note to plist
    [newNote save];

    //To get all saved notes
    NSArray *savedNotes = [Note savedNotes];
}

Source Code

Answer 5

Look, I am giving you the General Idea, you can use this code according to your requirement.

1) Get the "Path" of yourPlist.plist file :

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; 
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"yourPlist.plist"]; 

2) Insert data into the yourPlist :

NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
[dict setValue:categoryField.text forKey:@"Category"];
[dict setValue:nameField.text forKey:@"Name"];
[dict setValue:eventField.text forKey:@"Event"];

NSMutableArray *arr = [[NSMutableArray alloc] init];
[arr addObject:dict];

[arr writeToFile: path atomically:YES];

3) Retrieve data from the yourPlist :

NSMutableArray *savedStock = [[NSMutableArray alloc] initWithContentsOfFile: path];
for (NSDictionary *dict in savedStock) {
     NSLog(@"my Note : %@",dict);
}

Answer 6

You can use NSKeyedUnArchiver to retrieve the data. It will over write if you try to write in the same file path