NSUserDefaults, saving data issue - iphone

So I have an app that lets you put in a title and an author on the front page, then you hit enter and it will go into the actual features of the app. I want to save the data with NSUserDefaults, so that when they click the enter button, it saves it *AND goes into the next view. I have it setup with the storybord already to go into the next view, but when I use this code:
-(IBAction)enter:(id)sender {
titleString = [[NSString alloc] initWithFormat:[title text]];
[title setText:titleString];
NSUserDefaults *titleDefault = [NSUserDefaults standardUserDefaults];
[titleDefault setObject:titleString forKey:#"stringkey"];
authorString = [[NSString alloc] initWithFormat:[author text]];
[title setText:authorString];
NSUserDefaults *authorDefault = [NSUserDefaults standardUserDefaults];
[authorDefault setObject:authorString forKey:#"stringkey2"];
}
It will always crash when you hit the button. I have all the NSStrings defined and such, so I don't see what the problem is. I also have it loading with:
title.text = [[NSUserDefaults standardUserDefaults] objectForKey:#"stringkey"];
author.text = [[NSUserDefaults standardUserDefaults] objectForKey:#"stringkey2"];
Under the viewdidload, so can I have some help as to why this wouldn't work?

Just to optimize your -enter:method:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:title.text forKey:#"stringkey"];
[defaults setObject:author.text forKey:#"stringkey2"];
[defaults synchronize]; // this will store them instantly!
For the crash: can you please provide us with the exact crash log? Maybe your Button is linked to an unknown selector...

First, there are a few questions about this: here, here. Try searching around first, and at least let people know why the duplicate questions you found didn't work for you.
Secondly, I think you might benefit from adding a synchronize. Use this:
titleString = [[NSString alloc] initWithFormat:[title text]];
[title setText:titleString];
NSUserDefaults *titleDefault = [NSUserDefaults standardUserDefaults];
[titleDefault setObject:titleString forKey:#"stringkey"];
[titleDefault synchronize];
authorString = [[NSString alloc] initWithFormat:[author text]];
[author setText:authorString];
NSUserDefaults *authorDefault = [NSUserDefaults standardUserDefaults];
[authorDefault setObject:authorString forKey:#"stringkey2"];
[authorDefault synchronize];
I also changed the [title setText:authorString]; line to [author setText:authorString];. I do, however, think it is a bit redundant the way you are allocating the NSStrings to the value of the text fields and then setting the text back to the value of the string you created. I don't get the need. Anyway, hope this helps.

Related

Retrieval of NSArray from NSUserDefaults returns empty array

I am experiencing strange behaviour with NSUserDefaults. I am initially storing an array to the user defaults in my AppDelegate.m:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSArray *weekdayIDs = [defaults objectForKey:#"weekdayIDs"];
if (weekdayIDs == nil) {
weekdayIDs = [NSArray arrayWithObjects:#"su", #"mo", #"tu", #"we", #"th", #"fr", #"sa", nil];
[defaults setObject:weekdayIDs forKey:#"weekdayIDs"];
}
[defaults synchronize];
Now in a different view controller ContentViewController.m, I want to retrieve the array:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSArray *weekdayIDs = [defaults objectForKey:#"weekdayIDs"];
But I just get an array without objects, although its count == 7. I also used arrayForKey: but with the same result. I added a screenshot from my breakpoint.
I am regularly using NSUserDefaults, but currently I am bit stuck on this. It's probably a stupid mistake, anyone care to help?
Thank you so much!
-- Update:
I also figured it might be a problem with the init of the NSArray in the first place, but even replacing its objects with manually created NSString *dwid_su = [NSString stringWithString:#"su"]; didn't work.
Your code works perfectly.
Just, print the description of you array and you will see what you want.
Right click on weekdayIDs variable and select Print Description of weekdayIDs
or use through lldb debugger console po weekdayIDs
or NSLog(#"%#", weekdayIDs);
Here the results.

Array within a NSDictionary: how to save to the NSUserDefaults

I would like to save Array/NSDictionary to NSUserDefaults but anything I try is just not working. Here is my code so please if you know how to do this, help me.
NSArray *oneArray = [NSArray arrayWithObjects:#"Radio One",nil];
NSDictionary *one = [NSDictionary dictionaryWithObject:oneArray forKey:#"Stations"];
NSArray *oneLinkArray = [NSArray arrayWithObjects:#"http://mobile.com:28000/",nil];
NSDictionary *oneLink = [NSDictionary dictionaryWithObject:oneLinkArray forKey:#"Stations"];
[data addObject:one];
[link addObject:oneLink];
The reason I need this is to put this station into favorites. So my thinking is to save these info in to NSUserDefaults and retrieve in favorites table.
Thanks and please any suggestion is welcomed and appreciated.
You can use something like this when you store everything into a dictionary
[[NSUserDefaults standardUserDefaults] setObject:link forKey:#"dictionary1"];
Or you can put everything into an array and store it like this
[[NSUserDefaults standardUserDefaults] setObject:data forKey:#"array1"];
You can access it again by using
NSDictionary * myDictionary = [[NSUserDefaults standardUserDefaults] dictionaryForKey:#"dictionary1"];
Typically adding an object into NSUserDefaults goes like this:
NSMutableDictionary *dictionaryToAdd = [[NSMutableDictionary alloc] init];
[dictionaryToAdd setObject:#"xyz" forKey:#"myKey"];
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
[myDefaults setObject:dictionaryToAdd forKey:#"someKey"];
[myDefaults synchronize];
A few things on your code above though - you're adding stuff into 'data' and 'link' but I don't see those in your code, so I'm assuming those arrays exist somewhere.
To sum it up - declare an NSUserDefaults object, set objects into it like an NSDictionary, and then synchronize it to save data.
Additional code as requested:
//You have an array named arrayToAdd that has already been created
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
[myDefaults setObject:arrayToAdd forKey:#"SomeKeyThatYouMakeUp"];
[myDefaults synchronize];
//You want to get the array out of NSUserDefaults
NSArray *mySavedArray;
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
mySavedArray = [myDefaults objectForKey:#"SomeKeyThatYouMakeUp"];

How to keep my data in a array-iphone sdk

I'm trying to create an application, and in that I'm receiving some contents from net and loading into and array, if I quit and run the app again i'm losing the data. How can I store the data in the app itself. Should I use some kind of database? If so which one and how can I implement that? I need to store only some string variables.
EDIT:
My app is tabbar based app, and have two tabs. Loading the arrays in one tab and loading that array in a table in the other VC. once I load the array and move to the second tab, the table is loaded with the array. If i go back and add few more values and then if i check, the added datas is not displayed in the table. And also, when I quit the app the table lose all the values, I need to keep the values in the table, even after i quit the app. How can I do that?
here is my code:
in viewdidload:
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
[simplePlistDb setBool:YES forKey:#"isItWorking"];
[simplePlistDb setObject:alertList forKey:#"myArray"];
[simplePlistDb synchronize];
in cellforrowatindexpath:-
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
BOOL flag = [simplePlistDb boolForKey:#"isItWorking"];
if (flag)
{
NSArray *myArray = [simplePlistDb objectForKey:#"myArray"];
for (NSString *str in myArray){
NSLog(#"Str:%#", str);
[loadArray addObject:str];
}
cell.textLabel.text = [loadArray objectAtIndex:indexPath.row];
}
Thank you.
You will want to look into Core Data if you want to save a decent amount of data to the iPhone. However, if not, you can just load the items in the array into a plist and load them from there at launch.
Plist Writing: How to create a new custom property list in iPhone Applications
CoreData: http://www.raywenderlich.com/934/core-data-tutorial-getting-started
Edit--->
As Nekto said, you can also use NSUserDefaults, but I advise mainly using NSUserDefaults for simple NSStrings and integers.
I think for your purposes NSUserDefaults will be enough : NSUserDefaults Class Reference.
Examples:
// save
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
[simplePlistDb setBool:YES forKey:#"isItWorking"];
[simplePlistDb setObject:[NSArray arrayWithObjects:#"very", #"cool", nil]];
[simplePlistDb synchronize];
// restore
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
BOOL flag = [simplePlistDb boolForKey:#"isItWorking"];
if (flag)
{
NSArray *myArray = [simplePlistDb objectForKey:#"myArray"];
for (NSString *str in myArray)
NSLog(#"%#", str);
}
You can use NSUserDefaults in order to store your data till the time your app is installed in your device.
How to write in NSuserDefaults:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:#"yourObject1" forKey:#"correspopndingKey1"];
[defaults setObject:#"yourObject2" forKey:#"correspopndingKey2"];
[defaults synchronize];
How to read from NSuserDefaults:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *temp1 = [defaults objectForKey:#"correspopndingKey1"];
NSString *temp2 = [defaults objectForKey:#"correspopndingKey2"];
You can store NSArray in a similar way.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:objArray forKey:#"correspopndingKey"];
[defaults synchronize];

Saving and Retrieving UILabel value with NSUserDefaults

I trying to save UILabel value to NSUserDefaults. I did IBAction with this code:
-(IBAction)saveData:(id)sender {
NSString *resultString = label.text;
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setObject:resultString forKey:#"result"];
[prefs synchronize];
}
Then, I connect it to button with Touch Up Inside.
What log shows after I pressed the button:
result = 0;
When I pressed a second time, then it works.
result = "28.34";
What I'm doing wrong and how can I retrieve a result?
EDIT
With this code I display result in log. I put it to same action.
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] dictionaryRepresentation]);
Your code looks correct, so the issue is probably not the function you posted but rather the code that contains your NSLog. You might be logging the value in a way that misses the first time it gets set.
Your log statement should be
NSLog(#"%#",[[NSUserDefaults
standardUserDefaults]
objectForKey:#"result"]);
This should be after you set the object in NSUserDefaults.
Add this to your applicationDidFinishLaunching in appDelegate or in init method in viewController(you have to create one) :
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if(prefs == nil)
{
[prefs setObject:#"anything" forKey:#"result"];
[prefs synchronize];
}

Cannot set NSUserDefaults field

I have the following code in my initialization (first time) of my app:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=#"1";
[defaults setObject:uid forKey:#"init_val"];
[defaults synchronize];
Much later in the code (in response to a button press) I check the value using:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *initVal=[defaults objectForKey:#"init_val"];
initVal is always nil. I have checked and init_val is set up exactly the same in my settings bundle as another field that I can set and read from without issue (they are both set up with a single field named "Key".
#mlewis54:
You can try this code. I am very sure that it will work for you.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=#"1";
[defaults setObject:uid forKey:#"init_val"];
[defaults synchronize];
For Retrieving Data You Should Use The Following Code :
NSString *initVal=[[NSUserDefaults standardUserDefaults] valueForKey:#"init_val"];
OR
NSString *initVal=[[NSUserDefaults standardUserDefaults] objectForKey:#"init_val"];
EDIT:
If still it gives nil, then you can use the following code:
NSString *initVal=[NSString stringWithFormat:#"%#",[[NSUserDefaults standardUserDefaults] valueForKey:#"init_val"]];
OR
NSString *initVal=[NSString stringWithFormat:#"%#",[[NSUserDefaults standardUserDefaults] objectForKey:#"init_val"]];
Hope this helps you.
Decelare this at an event on click of button ...
NSUserDefaults *savedData = [NSUserDefaults standardUserDefaults];
[savedData setObject:userEmailTextField.text forKey:#"userid"];
and on load load the data and check the value you have entered is showing or not...
userEmailTextField.text =[[NSUserDefaults standardUserDefaults]objectForKey:#"userid"];
You need to use the line
NSString *initVal = [defaults stringForKey:#"init_val"];
- since it's a String you must use stringForKey. You can similarly use boolForKey to get a boolean value.
There's nothing wrong in your code, i tried to copy it in my project and it worked good,
so your error could be probably when you check initVal...
what's the code you use to see if initVal is nil?
and are you sure that when/where you check initVal, that var/oblect is still visible ?
try to insert this immediately after your reading code:
NSLog(#"____text read in pref: %#", initVal);
it writes this in my console window -> __text read in pref: 1
of course it's an NSString, i hope you keep it in mind it's not an int or a NSNumber when you check it...
luca
It might be that the initialisation isn't happening. Put an NSLog in there to check it's executed.
It works fine for me with the same code:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=#"1";
[defaults setObject:uid forKey:#"init_val"];
[defaults synchronize];
NSUserDefaults *defaultss = [NSUserDefaults standardUserDefaults];
NSString *initVal=[defaultss objectForKey:#"init_val"];
NSLog(#"Value of initVal: %#",initVal);
O/P on console: Value of initVal: 1
So try to do it with the same code with print on console.
Are you sure you properly initialize NSUserDefaults? When I initialize, in my app delegate, I always create the default user defaults by creating a dictionary of the default values then:
[[NSUserDefaults standardUserDefaults] registerDefaults:appDefaults];
Where appDefaults is the dictionary. Then you should be able to access them correctly.