I'm currently pulling my hair out trying to generate an info_hash from a torrent file I've downloaded. I created the Torrent file using uTorrent and using PeerTracker as my tracking software.
I'm using an updated version of the code found here:
https://code.google.com/p/rouge-server/source/browse/trunk/driver/objective-c/RougeDriver/BEncoding.m?r=88
{
announce = "http://sub.url.com:8080/announce.php";
"created by" = "uTorrent/1870";
"creation date" = 1425134140;
encoding = "UTF-8";
info = {
length = 4;
name = "test.txt";
"piece length" = 16384;
pieces = "\U00a9J\U00e8\U00c2\U00c3\U00b1\U00f5\U00b6L\bs\U201d\U00eb\U00c8\U00e1\U00f2/\U00aa\U201d";
};
}
Below is the exact encoding method I'm using:
+ (void)encode:(id)object toString:(NSMutableString *)string
{
if([object isKindOfClass:[NSDictionary class]])
{
NSDictionary *dictionary = (NSDictionary *)object;
[string appendString:#"d"];
for(id key in [dictionary allKeys])
{
[self encode:key toString:string];
[self encode:[dictionary objectForKey:key] toString:string];
}
[string appendString:#"e"];
}
else if([object isKindOfClass:[NSString class]])
{
NSString *stringObject = (NSString *)object;
NSString *format = #"%lu:%#";
[string appendFormat:format, [string length], stringObject];
}
else if([object isKindOfClass:[NSArray class]])
{
NSArray *array = (NSArray *)object;
[string appendString:#"l"];
for(id item in array)
{
[self encode:item toString:string];
}
[string appendString:#"e"];
}
else if([object isKindOfClass:[NSNumber class]])
{
NSNumber *number = (NSNumber *)object;
NSString *format = #"i%de";
[string appendFormat:format, [number intValue]];
}
}
This is my first time working with Torrents and bencoding. I know I'm only supposed to Encode the "info" dictionary contained within the main dictionary.
Does anyone one know where I could be going wrong here?
The actual pieces content is data:
0xa9, 0x4a, 0x8f, 0xe5, 0xcc, 0xb1, 0x9b, 0xa6, 0x1c, 0x4c, 0x08, 0x73, 0xd3, 0x91, 0xe9, 0x87, 0x98, 0x2f, 0xbb, 0xd3
As #Encombe states this is the SHA1 hash.
From Wikipedia:
The specification does not deal with encoding of characters outside the ASCII set; to mitigate this, some BitTorrent applications explicitly communicate the encoding (most commonly UTF-8) in various non-standard ways.
And pieces is hex data, not UTF-8.
I finally found the solution to this issue. As everyone suspected it was an encoding issue.
I followed the instructions from this SO:
Calculating the info-hash of a torrent file
However, I made one small tweak:
+ (NSDictionary *)decodeDictionary:(HTData *)data
{
NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
[data getNextCharacter];
while([data showNextCharacter] != 'e')
{
NSString *key = [self decodeString:data];
id object;
if([key isEqualToString:#"info"])
{
NSInteger startIndex = [data getCurrentIndex];
NSInteger endIndex;
object = [self decodeNextObject:data];
endIndex = [data getCurrentIndex];
NSMutableData *charData = [[NSMutableData alloc] init];
for(NSInteger i = startIndex; i < endIndex; i++)
{
char c = [data charAtIndex:i];
[charData appendBytes:&c length:1];
}
NSData *hashedInfo = [charData SHA1];
[dictionary setObject:hashedInfo forKey:#"info_hash"];
}
else
{
object = [self decodeNextObject:data];
}
[dictionary setObject:object forKey:key];
}
[data getNextCharacter];
return dictionary;
}
I'm now calculating the hash within the dictionary decoder. I'm also working with individual chars and appending them directly to an NSMutableData object. This avoids the encoding issues I had and generates the correct hash.
Not the most elegant solution but I'm just glad it works.
With all the URL-handling objects lying around in the standard Cocoa libraries (NSURL, NSMutableURL, NSMutableURLRequest, etc), I know I must be overlooking an easy way to programmatically compose a GET request.
Currently I'm manually appending "?" followed by name value pairs joined by "&", but all of my name and value pairs need to be manually encoded so NSMutableURLRequest doesn't fail entirely when it tries to connect to the URL.
This feels like something I should be able to use a pre-baked API for.... is there anything out of the box to append an NSDictionary of query parameters to an NSURL? Is there another way I should approach this?
Introduced in iOS8 and OS X 10.10 is NSURLQueryItem, which can be used to build queries. From the docs on NSURLQueryItem:
An NSURLQueryItem object represents a single name/value pair for an item in the query portion of a URL. You use query items with the queryItems property of an NSURLComponents object.
To create one use the designated initializer queryItemWithName:value: and then add them to NSURLComponents to generate an NSURL. For example:
NSURLComponents *components = [NSURLComponents componentsWithString:#"http://stackoverflow.com"];
NSURLQueryItem *search = [NSURLQueryItem queryItemWithName:#"q" value:#"ios"];
NSURLQueryItem *count = [NSURLQueryItem queryItemWithName:#"count" value:#"10"];
components.queryItems = #[ search, count ];
NSURL *url = components.URL; // http://stackoverflow.com?q=ios&count=10
Notice that the question mark and ampersand are automatically handled. Creating an NSURL from a dictionary of parameters is as simple as:
NSDictionary *queryDictionary = #{ #"q": #"ios", #"count": #"10" };
NSMutableArray *queryItems = [NSMutableArray array];
for (NSString *key in queryDictionary) {
[queryItems addObject:[NSURLQueryItem queryItemWithName:key value:queryDictionary[key]]];
}
components.queryItems = queryItems;
I've also written a blog post on how to build URLs with NSURLComponents and NSURLQueryItems.
You can create a category for NSDictionary to do this -- there isn't a standard way in the Cocoa library that I could find either. The code that I use looks like this:
// file "NSDictionary+UrlEncoding.h"
#import <cocoa/cocoa.h>
#interface NSDictionary (UrlEncoding)
-(NSString*) urlEncodedString;
#end
with this implementation:
// file "NSDictionary+UrlEncoding.m"
#import "NSDictionary+UrlEncoding.h"
// helper function: get the string form of any object
static NSString *toString(id object) {
return [NSString stringWithFormat: #"%#", object];
}
// helper function: get the url encoded string form of any object
static NSString *urlEncode(id object) {
NSString *string = toString(object);
return [string stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
}
#implementation NSDictionary (UrlEncoding)
-(NSString*) urlEncodedString {
NSMutableArray *parts = [NSMutableArray array];
for (id key in self) {
id value = [self objectForKey: key];
NSString *part = [NSString stringWithFormat: #"%#=%#", urlEncode(key), urlEncode(value)];
[parts addObject: part];
}
return [parts componentsJoinedByString: #"&"];
}
#end
I think the code's pretty straightforward, but I discuss it in some more detail at http://blog.ablepear.com/2008/12/urlencoding-category-for-nsdictionary.html.
I wanted to use Chris's answer, but it wasn't written for Automatic Reference Counting (ARC) so I updated it. I thought I'd paste my solution in case anyone else has this same issue. Note: replace self with the instance or class name where appropriate.
+(NSString*)urlEscapeString:(NSString *)unencodedString
{
CFStringRef originalStringRef = (__bridge_retained CFStringRef)unencodedString;
NSString *s = (__bridge_transfer NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,originalStringRef, NULL, (CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ", kCFStringEncodingUTF8);
CFRelease(originalStringRef);
return s;
}
+(NSString*)addQueryStringToUrlString:(NSString *)urlString withDictionary:(NSDictionary *)dictionary
{
NSMutableString *urlWithQuerystring = [[NSMutableString alloc] initWithString:urlString];
for (id key in dictionary) {
NSString *keyString = [key description];
NSString *valueString = [[dictionary objectForKey:key] description];
if ([urlWithQuerystring rangeOfString:#"?"].location == NSNotFound) {
[urlWithQuerystring appendFormat:#"?%#=%#", [self urlEscapeString:keyString], [self urlEscapeString:valueString]];
} else {
[urlWithQuerystring appendFormat:#"&%#=%#", [self urlEscapeString:keyString], [self urlEscapeString:valueString]];
}
}
return urlWithQuerystring;
}
The other answers work great if the values are strings, however if the values are dictionaries or arrays then this code will handle that.
Its important to note that there is no standard way of passing an array/dictionary via the query string but PHP handles this output just fine
-(NSString *)serializeParams:(NSDictionary *)params {
/*
Convert an NSDictionary to a query string
*/
NSMutableArray* pairs = [NSMutableArray array];
for (NSString* key in [params keyEnumerator]) {
id value = [params objectForKey:key];
if ([value isKindOfClass:[NSDictionary class]]) {
for (NSString *subKey in value) {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)[value objectForKey:subKey],
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#[%#]=%#", key, subKey, escaped_value]];
}
} else if ([value isKindOfClass:[NSArray class]]) {
for (NSString *subValue in value) {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)subValue,
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#[]=%#", key, escaped_value]];
}
} else {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)[params objectForKey:key],
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#=%#", key, escaped_value]];
[escaped_value release];
}
}
return [pairs componentsJoinedByString:#"&"];
}
Examples
[foo] => bar
[translations] =>
{
[one] => uno
[two] => dos
[three] => tres
}
foo=bar&translations[one]=uno&translations[two]=dos&translations[three]=tres
[foo] => bar
[translations] =>
{
uno
dos
tres
}
foo=bar&translations[]=uno&translations[]=dos&translations[]=tres
I refactored and converted to ARC answer by AlBeebe
- (NSString *)serializeParams:(NSDictionary *)params {
NSMutableArray *pairs = NSMutableArray.array;
for (NSString *key in params.keyEnumerator) {
id value = params[key];
if ([value isKindOfClass:[NSDictionary class]])
for (NSString *subKey in value)
[pairs addObject:[NSString stringWithFormat:#"%#[%#]=%#", key, subKey, [self escapeValueForURLParameter:[value objectForKey:subKey]]]];
else if ([value isKindOfClass:[NSArray class]])
for (NSString *subValue in value)
[pairs addObject:[NSString stringWithFormat:#"%#[]=%#", key, [self escapeValueForURLParameter:subValue]]];
else
[pairs addObject:[NSString stringWithFormat:#"%#=%#", key, [self escapeValueForURLParameter:value]]];
}
return [pairs componentsJoinedByString:#"&"];
}
- (NSString *)escapeValueForURLParameter:(NSString *)valueToEscape {
return (__bridge_transfer NSString *) CFURLCreateStringByAddingPercentEscapes(NULL, (__bridge CFStringRef) valueToEscape,
NULL, (CFStringRef) #"!*'();:#&=+$,/?%#[]", kCFStringEncodingUTF8);
}
If you are already using AFNetworking (as was the case with me), you can use it's class AFHTTPRequestSerializer to create the required NSURLRequest.
[[AFHTTPRequestSerializer serializer] requestWithMethod:#"GET" URLString:#"YOUR_URL" parameters:#{PARAMS} error:nil];
In case you only require the URL for your work, use NSURLRequest.URL.
Here is a simple example in Swift (iOS8+):
private let kSNStockInfoFetchRequestPath: String = "http://dev.markitondemand.com/Api/v2/Quote/json"
private func SNStockInfoFetchRequestURL(symbol:String) -> NSURL? {
if let components = NSURLComponents(string:kSNStockInfoFetchRequestPath) {
components.queryItems = [NSURLQueryItem(name:"symbol", value:symbol)]
return components.URL
}
return nil
}
I took Joel's recommendation of using URLQueryItems and turned into a Swift Extension (Swift 3)
extension URL
{
/// Creates an NSURL with url-encoded parameters.
init?(string : String, parameters : [String : String])
{
guard var components = URLComponents(string: string) else { return nil }
components.queryItems = parameters.map { return URLQueryItem(name: $0, value: $1) }
guard let url = components.url else { return nil }
// Kinda redundant, but we need to call init.
self.init(string: url.absoluteString)
}
}
(The self.init method is kinda cheesy, but there was no NSURL init with components)
Can be used as
URL(string: "http://www.google.com/", parameters: ["q" : "search me"])
I've got another solution:
http://splinter.com.au/build-a-url-query-string-in-obj-c-from-a-dict
+(NSString*)urlEscape:(NSString *)unencodedString {
NSString *s = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)unencodedString,
NULL,
(CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ",
kCFStringEncodingUTF8);
return [s autorelease]; // Due to the 'create rule' we own the above and must autorelease it
}
// Put a query string onto the end of a url
+(NSString*)addQueryStringToUrl:(NSString *)url params:(NSDictionary *)params {
NSMutableString *urlWithQuerystring = [[[NSMutableString alloc] initWithString:url] autorelease];
// Convert the params into a query string
if (params) {
for(id key in params) {
NSString *sKey = [key description];
NSString *sVal = [[params objectForKey:key] description];
// Do we need to add ?k=v or &k=v ?
if ([urlWithQuerystring rangeOfString:#"?"].location==NSNotFound) {
[urlWithQuerystring appendFormat:#"?%#=%#", [Http urlEscape:sKey], [Http urlEscape:sVal]];
} else {
[urlWithQuerystring appendFormat:#"&%#=%#", [Http urlEscape:sKey], [Http urlEscape:sVal]];
}
}
}
return urlWithQuerystring;
}
You can then use it like so:
NSDictionary *params = #{#"username":#"jim", #"password":#"abc123"};
NSString *urlWithQuerystring = [self addQueryStringToUrl:#"https://myapp.com/login" params:params];
-(NSString*)encodeDictionary:(NSDictionary*)dictionary{
NSMutableString *bodyData = [[NSMutableString alloc]init];
int i = 0;
for (NSString *key in dictionary.allKeys) {
i++;
[bodyData appendFormat:#"%#=",key];
NSString *value = [dictionary valueForKey:key];
NSString *newString = [value stringByReplacingOccurrencesOfString:#" " withString:#"+"];
[bodyData appendString:newString];
if (i < dictionary.allKeys.count) {
[bodyData appendString:#"&"];
}
}
return bodyData;
}
Yet another solution, if you use RestKit there's a function in RKURLEncodedSerialization called RKURLEncodedStringFromDictionaryWithEncoding that does exactly what you want.
Simple way of converting NSDictionary to url query string in Objective-c
Ex: first_name=Steve&middle_name=Gates&last_name=Jobs&address=Palo Alto, California
NSDictionary *sampleDictionary = #{#"first_name" : #"Steve",
#"middle_name" : #"Gates",
#"last_name" : #"Jobs",
#"address" : #"Palo Alto, California"};
NSMutableString *resultString = [NSMutableString string];
for (NSString* key in [sampleDictionary allKeys]){
if ([resultString length]>0)
[resultString appendString:#"&"];
[resultString appendFormat:#"%#=%#", key, [sampleDictionary objectForKey:key]];
}
NSLog(#"QueryString: %#", resultString);
Hope will help :)
If you are already using AFNetwork, you can use their built in serializer to to produce an encoded URL;
NSString *baseURL = #"https://api.app.com/parse";
NSDictionary *mutableParameters = [[NSMutableDictionary alloc] initWithObjectsAndKeys:#"true",#"option1", data, #"option2", token, #"token", #"3.0", #"app", nil];
NSURLRequest *request = [[AFHTTPRequestSerializer serializer] requestWithMethod:#"GET" URLString:baseURL parameters:mutableParameters error:nil];
NSString *urlPath = request.URL.absoluteString;
NSLog(#"%#", urlPath); // https://api.app.com/parse?option1=true&option2=datavalue&token=200%3ATEST%3AENCODE ....
Note; this is an extension to an above answer. The edit queue is full so cannot be added to the existing answer.
I am using Mantle to parse some JSON data from Yelp.
For each business returned I get an NSArray of categories. This would be an example:
yelpCategories = (
(
"Wine Bars",
"wine_bars"
),
(
"Ice Cream & Frozen Yogurt",
icecream
)
);
yelpCategories is the name of the array that I save. Later on I am trying to parse the array into a string:
NSMutableString *yelpCats = [[NSMutableString alloc] init];
for (NSObject * obj in business.yelpCategories)
{
[yelpCats appendString:[NSString stringWithFormat:#"%#,",[obj description]]];
}
The issue is with the above. I am being returned a string just as "(" so I must be accessing the array incorrectly. How can I correctly access each object, ideally I would be looking for the end string o be #"Wine Bars, Ice Cream & Frozen Yogurt".
EDIT
The categories array: (
(
Pubs,
pubs
)
)
FINAL EDIT - Proposed Solution
for (NSArray *cats in business.yelpCategories)
{
NSString *category = [cats objectAtIndex:0];
if ([category length] > 0) {
category = [category substringToIndex:[category length] - 1];
}
if (cats == business.yelpCategories.lastObject) {
[yelpCats appendString:[NSString stringWithFormat:#"%#",category]];
} else {
[yelpCats appendString:[NSString stringWithFormat:#"%#, ",category]];
}
}
cell.yelpCategories.text = yelpCats;
Using the description of the object gives you what you see in the debugger, which includes extra carriage returns.
What you want to do is something like:
yelpCats = [yelpCategories componentsJoinedByString:#", "];
#jeffamaphone 's answer is the correct and best way of doing things however what your doing will almost work, I think your just confused on the contents of the array.
The yelpCategories array is an array of strings so you don't need to call stringWithFormat or call the description method. In fact [obj description] will return a string so you didn't even need stringWithFormat in your example and you would have gotten the same output. To make your original method work change to:
NSMutableString *yelpCats = [[NSMutableString alloc] init];
for (id obj in business.yelpCategories)
{
//obj is a string so we can just append it.
[yelpCats appendString:obj]];
}
Also noticed I changed NSObject *obj to just id obj, this is the idiomatic way and shorthand way of declaring NSObjects in objective-c. In this example however I would actually use (NSString *category in business.yelpCategories) instead for better readability. In this case you are declaring to everyone that you expect each object in the array to be a string and then if you wanted to use NSString methods on it inside the loop then you don't have to cast it.
for (NSArray *cats in business.yelpCategories)
{
NSString *category = [cats objectAtIndex:0];
if ([category length] > 0) {
category = [category substringToIndex:[category length] - 1];
}
if (cats == business.yelpCategories.lastObject) {
[yelpCats appendString:[NSString stringWithFormat:#"%#",category]];
} else {
[yelpCats appendString:[NSString stringWithFormat:#"%#, ",category]];
}
}
cell.yelpCategories.text = yelpCats;
I need to convert XML response to JSON and sand to the json To javaScript code.
My XML response:
<cell>
<Result>True</Result>
<sguid>02291c402-2220-422b-b199-f92f22e56d2f</sguid>
</cell>
I am using XMLReader supporting file from this site:
XMLReader
I am using this code to convert XML to JSON :
+ (NSString*) XMLToJson:(CXMLDocument *)xmlDocument
{
NSError *error = nil;
NSArray *resultNodes = [xmlDocument nodesForXPath:#"//cell" error:&error];
if(error)
NSLog(#"%#",error.description);
CXMLNode *cellNode = [resultNodes objectAtIndex:0];
NSLog(#"%#",cellNode.XMLString);
NSError *parseError = nil;
NSDictionary *xmlDictionary = [XMLReader dictionaryForXMLString:cellNode.XMLString error:&parseError];
NSLog(#"%#", xmlDictionary);
//{print this.
// cell = {
// Result = {
// text = True;
// };
// sguid = {
// text = "0391c402-1120-460b-b199-f92fffe56d2f";
// };
// };
//}
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:xmlDictionary
options:NSJSONWritingPrettyPrinted // Pass 0 if you don't care about the readability of the generated string
error:&error];
if(error)
NSLog(#"%#",error.description);
NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
NSLog(#"%#", jsonString);
return jsonString;
}
I got JSON response like this:
{
"cell" : {
"Result" : {
"text" : "True"
},
"sguid" : {
"text" : "0391c402-1120-460b-b199-f92fffe56d2f"
}
}
}
I need JSON response like this:
{
"cell": {
"Result": "True",
"sguid": "02291c402-2220-422b-b199-f92f22e56d2f"
}
}
Because then I send this json to javascript code I get that exception jquery mobile dont know parser this and throws an exception of syntax error.
I've seen programmers use this solution and is helping them but I still get the same result in this solution.
XML into JSON conversion in iOS
thanks
I just wrote a function for your problem, I tried it on with a couple of XMLs. Let me know if you find any issues
- (NSMutableDictionary *)extractXML:(NSMutableDictionary *)XMLDictionary
{
for (NSString *key in [XMLDictionary allKeys]) {
// get the current object for this key
id object = [XMLDictionary objectForKey:key];
if ([object isKindOfClass:[NSDictionary class]]) {
if ([[object allKeys] count] == 1 &&
[[[object allKeys] objectAtIndex:0] isEqualToString:#"text"] &&
![[object objectForKey:#"text"] isKindOfClass:[NSDictionary class]]) {
// this means the object has the key "text" and has no node
// or array (for multiple values) attached to it.
[XMLDictionary setObject:[object objectForKey:#"text"] forKey:key];
}
else {
// go deeper
[self extractXML:object];
}
}
else if ([object isKindOfClass:[NSArray class]]) {
// this is an array of dictionaries, iterate
for (id inArrayObject in (NSArray *)object) {
if ([inArrayObject isKindOfClass:[NSDictionary class]]) {
// if this is a dictionary, go deeper
[self extractXML:inArrayObject];
}
}
}
}
return XMLDictionary;
}
And use it like this
NSDictionary *clearXML = [[self extractXML:[yourParsedXMLDictionary mutableCopy]] copy];
Your problem in using XMLReader. For resolve this problem you can use XMLConverter instead of the XMLReader.
In my project i have implemented multiple service and getting response. Among that one WSDL service that returns one data set as a response,
+ (id)deserializeAsDictionary:(CXMLNode*)element {
NSLog(#"deserializeAsDictionary = %#, children: %d", element.stringValue, [element childCount]);
if([element childCount] == 1) {
CXMLNode* child = [[element children] objectAtIndex:0];
if([child kind] == CXMLTextKind) {
NSLog(#"child %# added", [child stringValue]);
return [[[element children] objectAtIndex:0] stringValue];
}
}
NSMutableDictionary* d = [NSMutableDictionary dictionary];
NSInteger i = 1;
NSString *objKey;
for(CXMLNode* child in [element children]) {
id v = [Soap deserialize:child];
if(v == nil) {
v = [NSNull null];
} else {
if([[child name] isEqualToString:#"(null)"]) {
objKey = [NSString stringWithFormat:#"%#",[child stringValue]];
} else if([[child name] isEqualToString:#"key"] || [[child name] isEqualToString:#"value"]) {
objKey = [NSString stringWithFormat:#"%#",[child name]];
} else {
objKey = [NSString stringWithFormat:#"%#%d",[child name],i++];
}
}
[d setObject:v forKey:objKey];
NSLog(#"child %# added", objKey);
}
return d;
}
soap class will use this method to convert that data set into dictionary. Its working perfectly in IOS 5 but its not working in ios 6. Application will crash in ios 6 and through error as " CXML copy with zone "Please help me to fix this issue.
I think u get the soap classes with ARC enabled for ios6.If so you need to update the soap request class.Please refer this link Sudzc with iOS 5 and ARC
I think it may useful to you