I would like to parse csv from webserver which gets updated everyday.I am using the csvparser from this link https://github.com/davedelong/CHCSVParser and I am using this code:
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 get this error :
No visible #interface for 'CHCSVParser' declares the selector 'initWithContentsOfCSVString:usedEncoding:error:'
I checked this link Load remote csv into CHCSVParser and its not working .I am a noob to ios ,Please let me know how to fix this .Really Appreciate the help.Thanks in Advance.
It should probably be:
NSError *err;
NSString *lunchFileURL = [[NSString stringWithFormat:#"http://www.somewhere.com/LunchSpecials.csv"] stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *lunchFile = [NSString stringWithContentsOfURL:[NSURL URLWithString:lunchFileURL]
encoding:NSUTF8StringEncoding
error:&err];
// if you're going to create a CHCSVParser yourself, the syntax is:
CHCSVParser *p = [[CHCSVParser alloc] initWithCSVString:lunchFile
encoding:NSUTF8StringEncoding
error:&err];
// or, if you're going to use NSArray+CHCSVAdditions.h, the syntax might be:
NSArray *array = [[NSArray alloc] initWithContentsOfCSVString:lunchFile
encoding:NSUTF8StringEncoding
error:&err];
Note:
You don't need to alloc/init the NSError object; these classes that take a NSError ** parameter will create the autorelease error object for you if they encounter an error; otherwise they leave it alone;
The CHCSVParser class method is not initWithContentsOfCSVString, but rather initWithCSVString;
Alternatively, if you use the NSArray class extension, then the syntax is arrayWithContentsOfCSVString or initWithContentsOfCSVString; and
You specified an encoding of &encoding, but this parameter is not a pointer, so I don't see how that can possibly be right; I've just specified the encoding.
I assume you want to use the NSArray+CHCSVAdditions category method initWithContentsOfCSVString or arrayWithContentsOfCSVString (which gives you an autorelease object), not the CHCSVParser, but it's up to you.
Related
I have a very simple xml file by name options.xml
<Dat>
<Name>Tom</Name>
<Option>1</Option>
</Dat>
Using NSXML I am trying to change "Tom" to "Jim" and save the file. How can I do that. I read many document and there is no straight forward solution. Can some one help me with the code ?
update: I ended up in trying with Gdatasxml
-(void)saveToXML
{
NSString* path = [[NSBundle mainBundle] pathForResource:#"options" ofType:#"xml"];
NSData *xmlData = [[NSMutableData alloc] initWithContentsOfFile:path];
NSError *error;
GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithData:xmlData options:0 error:&error];
GDataXMLElement *rootElement = [GDataXMLElement elementWithName:#"Dat"];
NSArray *mySettings = [doc.rootElement elementsForName:#"Dat"];
for (GDataXMLElement *mySet in mySettings)
{
NSString *name;
NSArray *names = [mySet elementsForName:#"Name"];
if (names.count > 0)
{
GDataXMLElement *childElement = (GDataXMLElement *) [names objectAtIndex:0];
name = childElement.stringValue;
NSLog(childElement.stringValue);
[childElement setStringValue:#"Jim"];
}
}
[xmlData writeToFile:path atomically:YES];
}
But this is not saving the data. Help.
Editing XML is a little difficult in iOS. You need to parse the original xml to a model and then form the xml.
You can make use of 3rd party library such as GDataXML for forming XML from a data source.
//Edited user info saved in a dictionary
NSDictionary *dictionary = #{#"Name": #"Jim", #"Option":#"1"};
GDataXMLElement *rootElement = [GDataXMLElement elementWithName:#"Dat"];
[dictionary enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
GDataXMLElement *element = [GDataXMLElement elementWithName:key stringValue:obj];
[rootElement addChild:element];
}];
//xml document is formed
GDataXMLDocument *document = [[GDataXMLDocument alloc]
initWithRootElement:rootElement];
NSData *xmlData = document.XMLData;
NSString *filePath = [self savedXMLPath];
//XML Data is written back to a filePath
[xmlData writeToFile:filePath atomically:YES];
Create a class that is essentially an XML "node". Then in your parser setup a system of these XML nodes in the same fashion as you read them. Then search through that body and find the element that you would like to change. Change it. Then write a function that goes through these "node" objects and writes a new NSString in XML format and save that string to file. There is no real easy way that I know of to write XML files. I'm sure someone has a library out there to do it, but I had very complex XML's to deal with so I wrote my own. If you would like specific code let me know and I can try to give you parts of what you may need.
You Can use GDATAXML for changing XML node
Here is Working Code snippet
NSString *XMLString = #"<Dat><Name>Tom</Name><Option>1</Option></Dat>";
NSError *error = nil;
GDataXMLElement *newElement = [[GDataXMLElement alloc] initWithXMLString: XMLString error: &error];
NSLog(#"New element: %# error: %#", newElement, error);
if(nil == error)
{
GDataXMLElement *childElement = [[newElement elementsForName: #"Name"] objectAtIndex: 0];
[childElement setStringValue:#"Jim"];
childElement = [[newElement elementsForName: #"Option"] objectAtIndex: 0];
[childElement setStringValue:#"2"];
}
NSLog(#"New element now: %#", newElement);
Check by using this code snippet
I have upgraded from XCODE 4 to 4.2 and now i have problems.
The following code worked pre 4.2 to read the file in "filePath":
// Fill myString with questions from the .txt file and then read .txt file
NSString *filePath = whatFile;
NSString *myString = [[NSString alloc] initWithContentsOfFile:filePath];
// Load array
NSArray* myArray = [myString componentsSeparatedByString:#"\r"];
NSLog (#"\n \n Number of elements in myArray = %i", [myArray count]);
With 4.2 the "initWithContentsOfFile" in the following code line is deprecated:
NSString *myString = [[NSString alloc] initWithContentsOfFile:filePath];
...and should be replaced with the below according to the manual:
NSString *myString = [NSString stringWithContentsOfFile:filePath encoding: NSUTF8StringEncoding error:&err];
and i can not get this to read the records in the same file by replacing the code line. BTW, i have defined the &err.
When i NSLog myString i get (null).
I am getting a bit desperate to solve this and would very much appreciate any help.
Cheers
NSLog the err variable if there is an error. Also NSLog filePath.
Perhaps the encoding is not UTF-8, are you sure about the encoding?
The best non-UTF-8 encoding bet is NSMacOSRomanStringEncoding which supports 8-bit characters.
Try :
NSError* error = nil;
NSStringEncoding encoding;
NSString *fileContent = [NSString stringWithContentsOfFile:filePath usedEncoding:&encoding error:&error];
If that does not works, try in your code : NSASCIIStringEncoding
The file probably doesn't contain a UTF8 encoded string. See apple's documentation, which has an example of reading a file where you do not know the encoding: Reading data with an unknown encoding
You need to use the [string|init]WithContentsOfFile:usedEncoding:error method, and if that fails there are a few more things you can try before finally presenting an error message to the user (for example, try reading it as an NSAttributedString).
For example, you could do this:
// Fill myString with questions from the .txt file and then read .txt file
NSString *filePath = whatFile;
NSStringEncoding encoding;
NSError *error;
NSString *myString = [[NSString alloc] initWithContentsOfFile:filePath usedEncoding:&encoding error:&error];
if (!myString) {
myString = [[NSString alloc] encoding:NSUTF8StringEncoding error:&error]
}
if (!myString) {
myString = [[NSString alloc] encoding:NSISOLatin1StringEncoding error:&error]
}
if (!myString) {
NSLog(#"error: %#", error);
return;
}
// Load array
NSArray* myArray = [myString componentsSeparatedByString:#"\r"];
NSLog (#"\n \n Number of elements in myArray = %i", [myArray count]);
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?
What does mean? I get this error when trying to iterate through a file in Cocoa obj-c.
I can't find any information on the web.
Would appreciate some help. Thanks.
EDIT
I've been following this tutorial (link) to preload Core Data. I've tried creating a Cococa application and have also tried doing this from within my iPhone app. I think all my setup code for Core Data is fine. Whenever this method is called I get EXEC BAD ACCESS.
- (void)loadInitialData
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
// name ZSTREET_1 ZSTREET_2 ZCITY ZZIP ZURL ZTEL latitude longitude
NSString *path = [[NSBundle mainBundle] pathForResource:#"placesdata" ofType:#"txt"];
NSString *fileString = [NSString stringWithContentsOfFile:path]; // reads file into memory as an NSString
NSArray *lines = [fileString componentsSeparatedByString:#"\r"]; // each line, adjust character for line endings
NSManagedObjectContext *context = [self managedObjectContext];
for (NSString *line in lines)
{
NSLog(line);
NSString* string = [[NSString alloc] initWithUTF8String:line];
NSArray *parts = [string componentsSeparatedByString:#"\t"];
// value mapping
NSString *name = [parts objectAtIndex:0];
NSString *street_1 = [parts objectAtIndex:1];
NSString *street_2 = [parts objectAtIndex:2];
NSString *city = [parts objectAtIndex:3];
NSString *zip = [parts objectAtIndex:4];
NSString *url = [parts objectAtIndex:5];
NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterDecimalStyle];
NSNumber *latitude = [f numberFromString:[parts objectAtIndex:6]];
NSNumber *longitude = [f numberFromString:[parts objectAtIndex:7]];
[f release];
// splitting the parts to create the objects
Place *place = (Place *)[NSEntityDescription insertNewObjectForEntityForName:#"Place" inManagedObjectContext:context];
Address *address = (Address *)[NSEntityDescription insertNewObjectForEntityForName:#"Address" inManagedObjectContext:context];
Location *location = (Location *)[NSEntityDescription insertNewObjectForEntityForName:#"Location" inManagedObjectContext:context];
// set attributes
[place setValue:name forKey:#"name"];
[address setValue:street_1 forKey:#"street_1"];
[address setValue:street_2 forKey:#"street_2"];
[address setValue:city forKey:#"city"];
[address setValue:zip forKey:"#zip"];
[address setValue:url forKey:#"url"];
[location setValue:latitude forKey:#"latitude"];
[location setValue:longitude forKey:#"longitude"];
// link the objects together
[place setValue:address forKey:#"address"];
[place setValue:location forKeyPath:#"address.location"];
[string release];
}
NSLog(#"Done initial load");
NSError *error;
if (![context save:&error]) {
NSLog(#"Error saving: %#", error);
}
[context release];
[pool drain];
}
For other people running into this problem with entirely different code, this is a bit of a red herring.
The warning is from the debugger itself. The debugger creates a struct containing info for each object in the system. After the EXC_BAD_ACCESS, it tried to create one of these but was unable to. Note that this is a warning and not an error so it may even be expected in situations like this.
In any event, the details surrounding this don't matter. You've got to find the source of your EXC_BAD_ACCESS. A common cause is trying to access an object after it has been released.
For someone who comes across this in the future, I got this problem because I was doing this too much:
NSString* aString = #"";
for(int i=0; i<someLargeNumber; i++) {
aString = [aString stringByAppendingFormat:#"..."];
}
Once I switched to using NSMutableString, the problem was resolved.
This line is wrong and should produce a compiler warning:
NSString* string = [[NSString alloc] initWithUTF8String:line];
The method initWithUTF8String: expects an UTF-8 encoded C string and not a NSString object.
Before you continue you should fix all compiler warnings! And you also should check that the parts array actually contains as many objects as you expect. You also need to use a format string with NSLog, you might even crash there if your line contains any % characters.
I happen to run into EXC_BAD_ACCESS on a fairly regular basis (which is not a good thing), because we haven't enabled ARC yet.
I find the best way to track those errors down by using the Profiler in Zombie modus. This post shows you how to "hunt for zombies":
How do I set up NSZombieEnabled in Xcode 4?