I have a .txt file in which some data is present, when I stored it in an array I got 50000 words. I want to search the data from text file according to user input and show it on UITableview cell, how is it possible ?
Can any body help me?
Here is my code to read data from .txt file in viewDidLoad:
NSString *filepath = [[NSBundle mainBundle] pathForResource:#"myList" ofType:#"txt"];
NSError *error;
NSString *fileContents = [NSString stringWithContentsOfFile:filepath encoding:NSUTF8StringEncoding error:&error];
if (error)
NSLog(#"Error reading file: %#", error.localizedDescription);
// maybe for debugging...
NSLog(#"contents: %#", fileContents);
NSArray *listArray = [fileContents componentsSeparatedByString:#"\n"];
NSLog(#"items = %d", [listArray count]);
You should use fast enumeration using block. Those are fastest of all for loop iteration. But changing the value in that array at time of enumeration could cause a crash.
Here is a link of how to use block enumeration
Here is a link of how it performance wise.
Hope this helps you!!
Related
I'm trying to save recieving values in Txt file in delegate method using the below code. Those are Integer values, i'm putting those values in graph meanwhile saving in txt file.
but saving values in txt file is blocking graph plotting.
NSError *error;
NSString *filepath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject] stringByAppendingPathComponent:fileNameString];
NSString *string = [NSString stringWithContentsOfFile:filepath encoding:NSUTF8StringEncoding error:&error];
NSString *writeString = [NSString stringWithFormat:#"%#\n %#",string,values];
[writeString writeToFile:filepath atomically:YES encoding:NSUTF8StringEncoding error:&error];
PS: I used putting this piece of code dispatch_async, then its not saving all receiving values
If you are pushing on a thread and not all the values are being written, it sounds like a race condition with the thread. Try and do all your string processing on the write thread to make sure that thread is the 'source of truth' and has the most updated information.
I have this code:
NSString *studentList = _textIn.text;
NSString *path = [[self applicationDocumentsDirectory].path
stringByAppendingPathComponent:#"ClassOne.txt"];
[studentList writeToFile:path atomically:YES
encoding:NSUTF8StringEncoding error:nil];
NSLog(#"%#", studentList);
NSLog(#"students 1 saved");
I try to write to a text file on the phone system. When I try to read from that file with:
NSError *error;
NSString *strFileContent = [NSString stringWithContentsOfFile:[[NSBundle mainBundle]
pathForResource: #"classOne" ofType: #"txt"] encoding:NSUTF8StringEncoding error:&error];
_textIn.text = strFileContent;
The textfield comes up blank. The NSLog prints what was in the text field but when I try to load it up later the textfield is empty. how do I get the textfield to display what is in the file.
The writing part is alright. You are trying to read the file from your application main bundle instead of your original file path.
I'm trying to retrieve content of a csv file to NSString. Thats what I do:
NSString *strBundle = [[NSBundle mainBundle] pathForResource:#"socs" ofType:#"csv"];
NSLog(#"bundle path: %#",strBundle);
NSString *file = [NSString stringWithContentsOfFile:strBundle
encoding:NSUTF8StringEncoding
error:nil];
if ([[NSFileManager defaultManager]fileExistsAtPath:strBundle]) {
NSLog(#"file is there!!!");
}else {
NSLog(#"no file");
}
NSLog(#"file: %#",file);
NSArray *allLines = [file componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];
NSLog(#"lines: %lu",(unsigned long)[allLines count]);
file manager shows that the file is there. When i try to log the NSString or number of files it says null. I even created NSData object with the content of exactly the same file and when I logged the NSData object, I clearly saw that there is some data. Then when I tried to create NSString with the content of NSData, I had the same result as before - null. Maybe the problem is somewhere in the formatting of the file?
Any help will be appreciated :)
I see 3 issues:
You are passing a nil argument to the error: parameter in your stringWithContentsOfFile: line. If there's a possibility something might go wrong (and apparently there is), you should pass a real argument there so you can figure out what went wrong.
You can use componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet], but that has a tendency to produce blank "components" between every line. Plain old #"\n" works better in virtually all cases I've run into.
You should be checking fileExistsAtPath before you try to load it into the NSString
If you were truly able to create an NSData object from the path it doesn't necessarily mean it's correct data. But let's say it is, if you were not able to convert it to a NSString then you need to check your encoding parameter.
This question already has an answer here:
Writing a NSArray to file
(1 answer)
Closed 9 years ago.
I have an app which has several ViewControllers. Each ViewController has a question with 2-5 buttons as possible answers. The title of a button is saved to a NSMutableArray called submission. The user can go back to previous questions, change their answer, and the NSMutableArray will be updated accordingly. I need to save this array to file so new results can be saved into a UITableView each time the questionnaire is completed. I have researched and it sounds like a .plist is a good option, as all of my objects in the array are NSStrings.
A sample of my array:
2013-12-17 14:06:34.210 Questionnaire[1724:70b] (
1234,
"Dec 17, 2013",
Yes,
Games,
"Not Applicable",
Yes
)
"1234" is the User ID, the date is the Date of Birth, and the other submissions are the answers to each question.
My ViewControllers look like this:
MainViewController
InfoViewController <-- Array allocated + initialised, inserting ID and DoB
Q1ViewController <-- question
..
Q4ViewController <--question
ENDViewController <-- offers user options for Home or Results
ResultsViewController <-- UITableView ordered by User ID
SavedResultsViewController <-- UITableView showing complete submission
The NSMutableArray gets passed through each ViewController.
My questions: What method of saving to file would best suit my needs? (.plist, filetype, etc). Viewing the results on Excel would be nice (but not essential). Where should the save take place? I was thinking when the last object is inserted into the array on Q4 ViewController, so it would be saved to file when the ENDViewController is popped, is this logical? Do I need to create a new Objective-C file to store the data? I have saw a few tutorials explaining this, declaring each object in a separate NSObject file, although I'm not sure if that is needed as my objects are already stored in the array.
As you've probably guessed I am quite new to Objective-C and iOS programming, so any help offered is greatly appreciated. I am not sure how else to describe my problem, so apologies if the question is still unclear.
Edit: I have learnt a bit more about Objective-C since creating this post, and have decided to save my data to a .csv file. This file is strictly for the purpose of emailing, it doesn't get displayed on the UITableView (I am currently implementing Core Data for that). This solution might help someone in the future, so here it is:
// Set column titles for .csv
NSArray *columnTitleArray = #[#"User ID", #"DoB", #"Question 1", #"Question 2", #"Question 3", #"Question 4"];
NSString *columnTitle = [columnTitleArray componentsJoinedByString:#","];
NSString *columnTitleToWrite = [columnTitle stringByAppendingString:#"\n"];
// Separate submissions from array into cells
NSString *questionResults = [self.submission componentsJoinedByString:#","];
NSString *questionResultsToWrite = [questionResults stringByAppendingString:#"\n"];
// Find documents directory
NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
// Set file name and type
NSString *survey = [docPath stringByAppendingPathComponent:#"result.csv"];
// Create new file if none exists
if (![[NSFileManager defaultManager] fileExistsAtPath:survey]){
[[NSFileManager defaultManager] createFileAtPath:survey contents:nil attributes:nil];
// Set column titles for new file
NSFileHandle *fileHandle = [NSFileHandle fileHandleForUpdatingAtPath:survey];
[fileHandle writeData:[columnTitleToWrite dataUsingEncoding:NSUTF8StringEncoding]];
}
NSFileHandle *fileHandle = [NSFileHandle fileHandleForUpdatingAtPath:survey];
[fileHandle seekToEndOfFile];
[fileHandle writeData:[questionResultsToWrite dataUsingEncoding:NSUTF8StringEncoding]];
[fileHandle closeFile];
You could save your array as a JSON file. This would allow you to view it in a text editor, but not a spreadsheet. The following code will write it out as JSON to a file:
NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
url = [url URLByAppendingPathComponent:#"yourdata.json"];
NSError *e = nil;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:yourdata options:NSJSONWritingPrettyPrinted error:&e];
if (jsonData) {
[jsonData writeToFile:url.path atomically:YES];
}
You could also save your data as a plist file. The following will write the data to a plist:
NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
url = [url URLByAppendingPathComponent:#"yourdata.plist"];
NSError *e = nil;
NSData *plistData = [NSPropertyListSerialization dataWithPropertyList:yourdata format:NSPropertyListXMLFormat_v1_0 options:0 error:&e];
if (plistData) {
[plistData writeToFile:url.path atomically:YES];
}
Plists can be saved in binary or XML format, and the above will save it as XML format, which means the XML will also be readable with a text editor. Again, this won't be viewable as a spreadsheet. If you want to export your data in CSV format, you'll probably have to write your own code to output it.
You can use standard NSCoding protocol for saving data but in this case you can't read it in excel.
Or you can save it in xml.
Or you can manually create a csv (comma separated values) file and open it anywhere.
Implementation is up to you anyway :)
I know this is probably a silly question but I'm storing most of my game data in a plist - with that I'd like to include references to images used within my game - same hierarchal level as 'supporting files'. I have different types of images stored in 3 separate folders. One folder for example is called imageclue. How could I store the path in my plist, I'm stuck because I can't just store the path in my plist as string - filename.jpg. I've tried getting the path of the file but when I log it out it .
Sorry if I'm not explaining well and thank you in advance for any help :)
EDIT**
I have a plist file added to my program I don't want to programatically add to it as the images are constants - the screenshots below show a tutorial instead of the filename.jpg (because that won't work seen as my images are stored in a file) I wondered what path name do I use as a string.
The image is from a tutorial off of appcoda.com - where it says thumbnails are the image path files. If you look at where the images are stored on the left - they are stored with the program files. My images are in a folder in there so I'm confused as to what to enter in my plist for the image file.
Hope this clears up what I meant, sorry :)
Store three variables in .h file
#interface YourViewController : UIViewController
{
NSString *folder1;
NSString *folder2;
NSString *folder3;
}
in viewdidload:
-(void) viewdidLoad
{
//get the documents directory:
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//getting the folder name:
folder1 = [NSString stringWithFormat:#"%#/imageclue",
documentsDirectory];
folder2 = [NSString stringWithFormat:#"%#/folder2",
documentsDirectory];
folder3 = [NSString stringWithFormat:#"%#/folder3",
documentsDirectory];
}
-(NSArray*) getPlistFromFolder:(NSString*)folder imageName:(NSString*)image
{
NSString *imageTitle = [NSString stringWithFormat:#"%#/image",
folder];
NSArray *data = [[NSArray alloc] initWithContentsOfFile:plistName];
return data;
}
So in the plist file, just store the image name.
Hope this helps...
Do it like this,
NSDictionary *imagePaths = #{#"image 1": [NSHomeDirectory() stringByAppendingPathComponent:#"image 1"]};
[self writeToPlist:imagePaths];
- (void)writeToPlist:imagePaths:(id)plist{
NSError *error;
NSData *data = [NSPropertyListSerialization dataWithPropertyList:plist format:kCFPropertyListXMLFormat_v1_0 options:0 error:&error];
if(error){
NSLog(#"Could not write to file");
return;
}
[data writeToFile:[self plistPath] atomically:YES];
}
Like wise loading is simple as this;
[self loadImagePathForImageNamed:#"image 1"];
- (NSString*)loadImagePathForImageNamed:(NSString*)imageName{
}
- (NSString*)loadImagePathForImageNamed:(NSString*)imageName{
NSData *data = [NSData dataWithContentsOfFile:[self plistPath]];
NSString *error;
NSPropertyListFormat format;
NSDictionary *dictionary = [NSPropertyListSerialization propertyListFromData:data mutabilityOption:NSPropertyListImmutable format:&format errorDescription:&error];
if(error){
NSLog(#"Could not open plist %#", error);
return nil;
}
return dictionary[imageName];
}
You may have to handle the error when the file is not there by creating a new one, otherwise this should work.
You are storing path right way, just need to store filename of image with extension in plist when your images are in your Application Bundle, for more reference you can define key name Instead "item1", "item2" in your plist.
Now coming to actual Question, how to access image from plist
Step 1 : Read your recipes.plist from Application Bundle
NSString *bundlePath = [[NSBundle mainBundle] pathForResource:#"recipes" ofType:#"plist"];
NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:bundlePath];
Step 2 : Now Get Image/Thumbnails name out of it, which you want to load
Step 3 : Define following Function in your Controller, which returns image from name
- (UIImage *)getImageWithName:(NSString *)imageFileName
{
NSString *ext = [imageFileName pathExtension];
NSString *imagePath = [[NSBundle mainBundle] pathForResource:[imageFileName stringByDeletingPathExtension] ofType:ext];
return [UIImage imageWithContentsOfFile:imagePath];
}
HOW TO USE
Suppose you want to load Image with key "Item2" then write following code
NSString *imageFileName = [[dict objectForKey:#"Thumbnail"] valueForKey:#"Item2"];
UIImage *item2Image = [self getImageWithName:imageFileName];
For "Item6"
NSString *imageFileName1 = [[dict objectForKey:#"Thumbnail"] valueForKey:#"Item6"];
UIImage *item6Image = [self getImageWithName:imageFileName1];