I have file.txt data file in my project which is in resource folder.
Now i need to fetch the data from the file and load it into NSMutableArray.
how to approach to it.
First of all you need to read the file. And the you need to separate the string in components.
NSString *fileString = [NSString stringWithContentsOfFile:[[NSBundle mainBundle]pathForResource:#"test" ofType:#"txt"]
encoding:NSUTF8StringEncoding
error:nil];
NSMutableArray *stringsArray = [NSMutableArray arrayWithArray:[fileString componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]];
NSLog(#"Array:%#",[stringsArray description]);
Good luck.
Related
I'm trying to write a csv file. I have two arrays at hand - one with the titles (Name, Number etc), another with the actual values (Jon, 123 ...).
Now, after the following two operations:
[[titles componentsJoinedByString:#", "] writeToFile:file atomically:YES];
[[values componentsJoinedByString:#", "] writeToFile:file atomically:YES];
only the values array is written to the file. I realise that I may need to open the file again, but how do I do that after writing the first array? Or what is it exactly that I'm doing wrong if this is not the case?
Thanks!
The second line is in fact overwriting the file you wrote in the first line. One simple way to get around this problem would be to simply append the second string to the first (likely with an '\n' in between since you're making a csv file) and writing that string to your file:
NSString *str1 = [[titles componentsJoinedByString:#", "];
NSString *str2 = [[values componentsJoinedByString:#", "];
NSString *outputStr = [str1 stringByAppendingFormat:#"\n%#", str2];
[outputStr writeToFile:file atomically:YES];
Second time it replaces the old contents. So you could read the old content, append the old content with the new content and save on file.
Write first row
[[titles componentsJoinedByString:#", "] writeToFile:file atomically:YES];
Where you need to add another row every time
NSString *previousContent = [[NSString alloc] initWithContentsOfFile:file usedEncoding:nil error:nil];
NSString *str2 = [[values componentsJoinedByString:#", "];
NSString *outputStr = [previousContent stringByAppendingFormat:#"\n%#", str2];
[outputStr writeToFile:file atomically:YES];
i am trying to parse a text file saved in doc dir below show is the code for it
NSArray *filePaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString *docDirPath=[filePaths objectAtIndex:0];
NSString *filePath=[docDirPath stringByAppendingPathComponent:#"SKU.txt"];
NSError *error;
NSString *fileContents=[NSString stringWithContentsOfFile:filePath];
NSLog(#"fileContents---%#",fileContents);
if(!fileContents)
NSLog(#"error in reading file----%#",error);
NSArray *values=[fileContents componentsSeparatedByString:#"\n"];
NSLog(#"values-----%#",values);
NSMutableArray *parsedValues=[[NSMutableArray alloc]init];
for(int i=0;i<[values count];i++){
NSString *lineStr=[values objectAtIndex:i];
NSLog(#"linestr---%#",lineStr);
NSMutableDictionary *valuesDic=[[NSMutableDictionary alloc]init];
NSArray *seperatedValues=[[NSArray alloc]init];
seperatedValues=[lineStr componentsSeparatedByString:#","];
NSLog(#"seperatedvalues---%#",seperatedValues);
[valuesDic setObject:seperatedValues forKey:[seperatedValues objectAtIndex:0]];
NSLog(#"valuesDic---%#",valuesDic);
[parsedValues addObject:valuesDic];
[seperatedValues release];
[valuesDic release];
}
NSLog(#"parsedValues----%#",parsedValues);
NSMutableDictionary *result;
result=[parsedValues objectAtIndex:1];
NSLog(#"res----%#",[result objectForKey:#"WALM-FT"]);
The problem what i am facing is when i try to print lineStr ie the data of the text file it is printing as a single string so i could not able to get the contents in line by line way please help me solve this issue.
Instead use:
- (NSArray *)componentsSeparatedByCharactersInSet:(NSCharacterSet *)separator
it covers several different newline characters.
Example:
NSArray *values = [fileContents componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];
for (NSString *lineStr in values) {
// Parsing code here
}
ALso seperatedValues is over released. First one is created with alloc init, then on the next line it is replaced by the method componentsSeparatedByString. So the first one od lost without being released, that is a leak. Later the seperatedValues created by componentsSeparatedByString is released but it is already auto released by componentsSeparatedByString to that is an over release;
Solve all the retain/release/autorelease problem with ARC (Automatic Reference Counting).
Here is a version that uses convenience methods and omits over release:
NSArray *values = [fileContents componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];
for (NSString *lineStr in values) {
NSArray *seperatedValues = [lineStr componentsSeparatedByString:#","];
NSString *key = [seperatedValues objectAtIndex:0];
NSDictionary *valuesDic = [NSDictionary dictionaryWithObject:seperatedValues forKey:key];
[parsedValues addObject:valuesDic];
}
NSLog(#"parsedValues---%#",parsedValues);
Are you sure the line separator used in your text file is \n and not \r (or \r\n)?
The problem may come from this, explaining why you don't manage to split the files into different lines.
I am using Dave DeLong's CHCSVParser to parse a csv. I can parse the csv locally, but I cannot get it load a remote csv file. I have been staring at my MacBook way too long today and the answer is right in front of me. Here is my code:
NSString *urlStr = [[NSString alloc] initWithFormat:#"http://www.somewhere.com/LunchSpecials.csv"];
NSURL *lunchFileURL = [NSURL URLWithString:urlStr];
NSStringEncoding encoding = 0;
CHCSVParser *p = [[CHCSVParser alloc] initWithContentsOfCSVFile:[lunchFileURL path] usedEncoding:&encoding error:nil];
[p setParserDelegate:self];
[p parse];
[p release];
Thanks for any help that someone can give me.
-[NSURL path] is not doing what you're expecting.
If I have the URL http://stackoverflow.com/questions/4636428, then it's -path is /questions/4636428. When you pass that path to CHCSVParser, it's going to try and open that path on the local system. Since that file doesn't exist, you won't be able to open it.
What you need to do (as Walter points out) is download the CSV file locally, and then open it. You can download the file in several different ways (+[NSString stringWithContentsOfURL:...], NSURLConnection, etc). Once you've got either the file saved locally to disk or the string of CSV in memory, you can then pass it to the parser.
If this is a very big file, then you'll want to alloc/init a CHCSVParser with the path to the local copy of the CSV file. The parser will then read through it bit by bit and tell you what it finds via the delegate callbacks.
If the CSV file isn't very big, then you can do:
NSString * csv = ...; //the NSString containing the contents of the CSV file
NSArray * rows = [csv CSVComponents];
That will return an NSArray of NSArrays of NSStrings.
Similar to this last approach is using the NSArray category method:
NSString * csv = ...;
NSError * error = nil;
NSArray * rows = [NSArray arrayWithContentsOfCSVString:csv encoding:[csv fastestEncoding] error:&error];
This will return the same structure (an NSArray of NSArrays of NSStrings), but it will also provide you with an NSError object if it encounters a syntax error in the CSV file (ie, malformed CSV).
I think you need an NSString, not an NSURL object to pass to the parser so the extra part you are doing with changing the NSString to an NSURL is the issue. Looking at the CHCSVParser documentation, it looks like he wants NSString in the init.
So maybe you could do something like:
NSError *err = [[[NSError alloc] init] autorelease];
NSString *lunchFileURL = [[NSString stringWithFormat:#"http://www.somewhere.com/LunchSpecials.csv"] stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *lunchFile = [NSString stringWithContentsOfURL:[NSURL URLWithString:lunchFileURL] encoding:NSUTF8StringEncoding error:&err];
CHCSVParser *p = [[CHCSVParser alloc] initWithContentsOfCSVString:lunchFile usedEncoding:&encoding error:nil];
I am using the following code to open a file's contents and save it to another file.
when it runs the original file length is 793 but the saved file is 0. I have also tried just to copy the file. Nothing seems to work.
Is there some kind of permissions I'm missing on the documents directory?
NSError *error;
NSString *basePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* nGram = [basePath stringByAppendingPathComponent:#"contacts.gram"];
NSString *oGram = [basePath stringByAppendingPathComponent:#"/../vText.app/model/lm/TAR9230/contacts.gram"];
NSString *gramString = [[NSString alloc] initWithContentsOfFile:oGram encoding:NSUTF8StringEncoding error:&error];
BOOL ok = [gramString writeToFile:nGram atomically:NO encoding:NSUnicodeStringEncoding error:&error];
if(!ok) NSLog(#"Mayday!");
NSLog(#"%d",[gramString length]);
gramString = [[NSString alloc] initWithContentsOfFile:nGram encoding:NSUTF8StringEncoding error:&error];
NSLog(#"%d",[gramString length]);
This entire block is unnecessary. All you need is:
NSString *fp=[[NSBundle mainBundle] pathForResource:#"contacts" ofType:#"gram"];
NSString *gramString = [[NSString alloc] initWithContentsOfFile:fp
encoding:NSUTF8StringEncoding
error:&error];
You certainly don't want to try to directly access a file in the app bundle using a hardcoded path because the file isn't guaranteed to be in the same exact place in every build.
In the code you do have, you want to use the same encoding constant for reading as you did for writing. You write with NSUnicodeStringEncoding but you read with NSUTF8StringEncoding. These should overlap but why take the chance if you know the exact coding used?
How do I get an NSArray of the NAMES of all files stored in a specific directory such as: "http://www.someurl/somedirectory/"?
That's really something that has to be generated server-side, then parsed on the device. I know Apache has an option where you can turn on Directory Indexes, so you could do that, then download the generated directory index and parse the HTML (using an NSXMLParser or some other parsing library), adding an NSString to an NSMutableArray every time you find a file name.
Should be something along these lines..
NSURL* url = [NSURL URLWithString: #"http://address.tld/path/files.txt"];
NSString* data = [NSString stringWithContentsOfURL: url];
if(data)
{
NSArray* files = [data componentsSeparatedByString: #"\n"];
for(NSString* filename in files)
{
NSLog(#"%#", filename);
}
}