I am sorry to ask this but I have searched for hours on doing this but I really don't understand it. Please help me. I have a .plist file in my Xcode project and it's root is a Dictionary type. It contains about 50 more dictionaries. Inside the dictionary contains strings. (Dictionary(root) > Dictionary > String. I added a search field to my toolbar and linked it to my code. I am able to get what the user types but then how do I "search" after getting what the user typed? Is there a method for this and how do I link it into my .plist? Thank you so much!!!
You want to search for the user entered string in your Dictionary of Dictionaries?
You're going to have to iterate each dictionary, asking [dict objectForKey:userEntry] in each. Not sure if you want to only find first match or all matches too.
Additionally, you may want to create an abstraction of your Dictionary of Dictionaries to reduce the scale of the problem and clarify the API. In simpler terms, wrap your Dictionary of Dictionaries in a class and put a sensible (non-dictionary-based) set of methods on it. It's probably worth the effort.
To load the plist into a Dictionary, look at [Dictionary dictionaryWithContentsOfFile].
Edit: Filtering options on NSDictionary
Have you looked at the following options for filtering values in an NSDictionary:
[NSDictionary keysOfEntriesPassingTest:] (10.6 and later) or
take the [rootDictionary allValues] NSArray and use Predicates, perhaps like this.
Related
I do not understand how this makes sense. I put two objects in the discoveryinfo dictionary inside the MCNearbyServiceAdvertiser object that I create and the browser doesn't see the advertiser, yet when I move the second object out of the dictionary and comment it out at the end of the line, the browser sees the advertiser. Does the discoveryinfo dictionary only accept one object to work? I have a string as the first object and an array as the second. Here is what it looks like:
advertiser = [[MCNearbyServiceAdvertiser alloc] initWithPeer:myPeerID discoveryInfo:#{#"Name": [[NSString alloc] initWithString:myUniqueID], #"Peers": [[NSArray alloc] initWithArray:connectedPeersAry]} serviceType:#"Blahblah"];
And before that line, I tried this simpler format (but went to the above just in case the syntax was the problem):
advertiser = [[MCNearbyServiceAdvertiser alloc] initWithPeer:myPeerID discoveryInfo:#{#"Name": myUniqueID, #"Peers": connectedPeersAry} serviceType:#"FRCSCOUT"];
I guess I can put a dictionary or array inside the discoveryinfo dictionary, but I feel it's a pretty dumb way of doing things because a dictionary shouldn't ever be limited to one object for any case.
I'll go ahead and put my objects in another layer to "conserve space" inside the discoveryinfo dictionary, but if any of you find a better way of doing things or if you are seeing the same problem, please let me know.
You can have multiple objects in the discoveryInfo dictionary, but keep in mind that the dictionary will be encoded in a Bonjour TXT record. This imposes a few restrictions on what can be put into that dictionary.
As stated in the documentation for [MCNearbyServiceAdvertiser initWithPeer:discoveryInfo:serviceType:]:
This data is advertised using a Bonjour TXT record, encoded according to RFC 6763 (section 6). As a result:
The key-value pair must be no longer than 255 bytes (total) when encoded in UTF-8 format with an equals sign (=) between the key and the value.
Keys cannot contain an equals sign.
For optimal performance, the total size of the keys and values in this dictionary should be no more than about 400 bytes so that the entire advertisement can fit within a single Bluetooth data packet.
Well, found my problem. As quoted by Apple in their class reference for MCNearbyServiceAdvertiser:
"The content of discoveryInfo will be advertised within Bonjour TXT records, so you should keep the dictionary small for better discovery performance."
So, looks like I'll have to use a comma separated string of some sort...
EDIT
I misunderstood the Multipeer Connectivity API. I thought the roles were reversed and the Advertiser was basically the public host for a Multipeer Session, but it should be the Browser that invites Advertisers. I now just have the Unique ID generated as the discovery info.
Thank you all for your help and sorry for the API confusion on my part.
I'm a total newbie to Objective-C and have been tasked with an assignment to compare 2 builds of same app for differences in their Info.plist and Defaults.plist.
I have been able to figure out the steps to read the PLists from app bundle but am having difficulty figuring out how to compare EVERY key in PLists to its counterpart file. For illustration if I need to compare Info.plist between 2 app bundle (lets say build_100 and build_101), how do I recursively go to each key in build_100 and compare the same key in build_101 to verify if they are same or not.
Its easy if both PLists are same because isEqualToDictionary will return TRUE but problem occurs if something in a nested dictionary is different between both the builds.
Going through related queries here, it clear to me that the answer is that I write a recursive method that iterates through both PLists but I'm having a real frustrating time to figure out a way to do this for a nested dictionary like Info.plist.
So I've finally figured this thing out so thought of sharing it with others for future reference. I'm sure there'll be some other lost soul in future looking for something similar (or at least I hope :)).
The way I wrote my code was to:
Read both Plists in NSDictionaries
Treat one Plist as "to be tested" and other as the reference (to compare against) to find out if its a Pass/Fail
Loop through all keys in "to be tested" Plist and compare each one of them in "reference" Plist
When it came to compare an Array or Dictionary, this check (that's the part I was struggling with) had to be a recursive check
The code to write for step #1, 2, 3 is straight forward so I'm going to give the method I wrote for #4 which was the crux of my original question.
This function compareSourceObject() will take 3 arguments:
sourceObject: object to be tested
targetObject: object to compare against
trailPath: string that'll hold the entire path of the key that has failed
- (void)compareSourceObject:(id)sourceObject andTargetObject:(id)targetObject withBreadcrumbTrail:(NSString *)trailPath{
NSString *message = [[NSString alloc] init];
if ([sourceObject isKindOfClass:[NSDictionary class]]){
for(id item in sourceObject){
[self compareSourceObject:[sourceObject objectForKey:item] andTargetObject:[targetObject objectForKey:item] withBreadcrumbTrail:[trailPath stringByAppendingFormat:#"->%#", item]];
}
}
else if ([sourceObject isKindOfClass:[NSArray class]]){
for (int counter=0; counter %d", counter]];
}
}
else if(![sourceObject isEqual:targetObject]){
NSLog(#"Values do not match. Value in \"TestedDicationary\" is (%#) but the reference dict has (%#)", targetObject, sourceObject);
}
}
Hope this helps. Comments/Suggestions/Optimizations are more than welcome.
Take one plist, and interpret the properties as a set (NSSet) of string values, e.g.
:items:0:assets array
:items:0:assets:0:kind string VALUE
Note I am using /usr/libexec/PlistBuddy format to describe a property - path type [value].
Then do the same for the second plist and compare the sets using NSSet functions.
I am creating an iOS word game and need to import every word in the English dictionary. I have to check if a string is part of the array or set or whatever it may be. What is the best and most memory efficient way of importing and utilizing the data?
I feel like I'm working for them, haha, but LexiconText has a very nice product indeed, and it isn't too hard to determine if the word is in the dictionary or not:
Lexicontext *dictionary = [Lexicontext sharedDictionary];
BOOL wordExists = [dictionary containsDefinitionFor:#"MyWord"];
Note: I am not affiliated with lexicontext in any way, other than being a happy customer.
You should use sqlite or another database to store the dictionary. Then you don't have to load it all into memory, but get fast loading of words.
Newbie question here. I'd like to be able to specify through data (i.e. an XML file), the appropriate Objective-C message to send. Any advice on if this is possible or how I can do this?
The next best thing, if I can't do this, would be some way to create a map object that would correlate a key (an int) with a function (I guess also a selector). Is that possible if the above isn't?
If someone could point me to some tutorial or example code as reference, that'd be great. Right now I'm doing things with a big switch statement, and I don't like it. (I'm switching on the id and in each case, explicitly calling the method relevant to the particular id.)
I love that you asked this question; too often, I see Satan's Swollen Switch Statement. It's nice to see someone wanting to using a function-table instead.
If you're OK with using a property list file (which is usually encoded in XML), this is really easy.
Just make a property list where the root element is a dictionary, which maps from some keys to some selectors.
Key Type Value
----------------------------------------------
Root Dictionary
firstKey String someSelector
secondKey String anotherSelector
Load the contents of your property list into an NSDictionary:
id path = [[NSBundle mainBundle] pathForResource:#"filename" ofType:#"plist"];
id dict = [NSDictionary dictionaryWithContentsOfFile:path];
SEL selector = NSSelectorFromString([dict objectForKey:#"firstKey"]);
if ([someObject respondsToSelector:selector]) {
[someObject performSelector:selector];
}
Of course, you'll want to refactor this logic into an appropriate method, and probably cache the property list as an instance variable.
Note: I personally think it's better to just put this function table inline; property lists are cool, but I'm not sure that it is very helpful in this case. Also, if you are cool with using Objective-C++, std::map will allow you to get away with not wrapping and unwrapping the selectors in NSString objects, etc.
Instead of implementing my own I was wondering if anyone knows of a histogram or bag datastructure implementation in Objective-C that I can use.
Essentially a histogram is a hashmap of lists where the lists contain values that relate to their hash entry. A good example is a histogram of supermarket items where you place each group of items dairy, meat, canned goods in their own bag. You can then very easily access each group of items according to their type.
NSCountedSet is a multiset (aka "bag") that counts distinct objects, but doesn't allow duplicates. However, based on your explanation, I don't think that's what you need, and neither is a histogram, which automatically buckets values based on a set of (usually numerical) ranges.
I believe what you really want is a multimap, which is a "key to one-or-more values" relation. The data structures framework I maintain includes CHMultiDictionary, a multimap implementation. I won't claim by any means that it's perfect or complete, but I hope it may be helpful for your problem.
It sounds to me like you simply want a dictionary of arrays. You can put NSArrays as elements of NSDictionarys, something like:
NSMutableDictionary* dict = [NSMutableDictionary dictionary];
[dict setObject:[NSMutableArray arrayWithObjects:#"milk", #"eggs", #"cheese", nil] forKey:#"dairy"];
[dict setObject:[NSMutableArray arrayWithObjects:#"steak", #"sausages", #"mince", nil] forKey:#"meat"];
[[dict objectForKey:#"meat"] addObject:#"lamb"];
NSLog( #"Dictionary is %#", dict );
There's one in the GNU Objective-C Class library, but the docs appear to be pretty incomplete and the project's homepage must be currently having a problem -- still, if GPL software is acceptable for your project, you might want to download and check the sources.
CFIOMultimap apparently is an implementation of a multimap. However, as of the time of writing I couldn't get it to work. It returns nils all the time when I subscript.
Perhaps it can be fixed and adapted for your use.