So I am trying to concatenate a bunch of input strings together as one string so I can save that to a text file.
So far I am trying to write something like this
NSString *tempString = [[NSString alloc]initWithFormat:#"%#%#%#", text1, text2, text3];
The only problem with this is that I need a total of 30 strings stored this way. I need a way to do this without typing out each string name. Is there a way to use a for loop or something to accomplish this? Type the strings like this perhaps?
text(i)
So that the variable name would change each time it went through the for loop. I've tried doing something like this and I can't get it to work. If you can help me with this method or another way that you know to do it I would be very thankful.
Okay, so all of the answers here take the wrong approach (sorry guys).
The fundamental problem is that you are using your "text boxes" as a data source, when they should simply be views. When someone changes the text, you should immediately store them in your model (which could be a simple array) and then reference that model later. (This is part of MVC. Look it up if you aren't familiar, as you should be if you are programming for iOS!)
Here is what I would do. (I'm assuming that your "text boxes" are UITextField's.)
Set the delegate for each text field to your view controller.
Set the tag for each text field to a number which represents the order that you want the strings joined in. (ie 1-30)
If you don't have a separate class for your data model, then setup a declared property in your view controller which stores a reference to a NSMutableArray which can contain all of the strings in order. Let's call it dataSource. In viewDidLoad: set this to an actual mutable array filled with empty values (or previously stored values if you are saving them). The reason that we store empty values is so that we can replace them with the user entered strings for any index, even if they are entered out of order:
- (void)viewDidLoad
{
[super viewDidLoad];
self.dataSource = [[NSMutableArray alloc] initWithCapacity:20];
for(int i = 0; i < 30; i++)
[self.dataSource addObject:#""];
}
Then, use the following text field delegate method which stores the strings into the array as they are entered:
// This is called every time that a text field finishes editing.
- (void)textFieldDidEndEditing:(UITextField *)textField
{
if (textField.tag > 0)
[self.dataSource replaceObjectAtIndex:textField.tag-1 withObject:textField.text];
}
Congratulations! All of your strings are now stored in one array. Now we just have to combine them all:
NSMutableString *theString = [self.dataSource componentsJoinedByString:#""];
Note that I have NOT tested all of this so there may be typos. This should get you pointed in the right direction though!
If you set up your text boxes in Interface Builder with an IBOutletCollection(UITextField) you would have an array of text boxes that you could access the text value using KVC and join them.
//interface
...
#property (nonatomic, strong) IBOutletCollection(UITextField) NSArray *textBoxes;
//implementation
...
NSString *tempString = [[textBoxes valueForKey:#"text"]
componentsJoinedByString:#""];
Using iOS 4's IBOutletCollection
If you programmatically create your text boxes then add them to an array as you create them.
NSMutableString's appendString: method is your friend.
NSArray *strings = [NSArray arrayWithObjects: #"Hi", #" there", #" dude", nil];
NSMutableString *result = [[NSMutableString alloc] init];
for (NSString *string in strings) {
[result appendString:string];
}
NSLog(#"result: %#", result); // result: Hi there dude
Related
I'm having a little difficulty with a JSON service that I'm consuming and iterating over. When I consume the service I am looping over the data as you would expect because of the number of records.
I'm saving that loop'ed data into an NSArray which I use later in a UITableView. Next I'm simply allowing the user to tap the selected row (from the json data result) to show more detail. Pretty simple so far.
Every element from the JSON service is NSString. So far nothing tricky. However, one element within the NSArray after the service has been put into the NSObject is showing HEX code, see below.
altitude NSString * 0x7ff8d4cd3d30 0x00007ff8d4cd3d30
Of course the app has a meltdown because it can't figure out what HEX is when I'm using that NSArray object to display key elements i.e. altitude. Now the odd thing is every other element within the NSArray looks like this see below.
latitude __NSCFString * #"21.45852" 0x00007ff8d4ca54f0
I have read a few suggestions stating this is normal for NSString and JSON data. But not really how to fix it.
What I have found is that NSArray after the JSON is complete is changing just that one element. I have also tried changing it from an INT to an NSString however same result (I know its a NSString in the first place btw, I was just trying different ideas.)
Abstract of JSON Call and loop to add into NSArray object.
//Do something with returned array
dispatch_async(dispatch_get_main_queue(), ^{
NSDictionary *pilotJson = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
//Loop through the JSON array
NSArray *currentPilotsArray = [pilotJson valueForKeyPath:#""];
//set up array and json call
pilotsArray = [[NSMutableArray alloc]init];
NSArray *keys=[pilotJson allKeys];
for (NSString *key in keys){
NSDictionary *elementDictionary=pilotJson[key];
NSString *altitude = elementDictionary[#"altitude"];
NSInteger n = [altitude intValue];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
formatter.numberStyle = NSNumberFormatterDecimalStyle;
NSString *string = [formatter stringFromNumber:#(n)];
NSString *nAltitude = [NSString stringWithFormat:#"%# ft", string];
[pilotsArray addObject:[[LiveMap alloc]initWithaltitude:nAltitude ]];
.
.
.
So when I get to this point of the code where the user taps the relevant record I get a crash and the application aborts. I'm assuming this is from the above NSString vs __NSCFString
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
//Pass the details the the detail view controller
PilotsFlightDetailViewController *detail = [self.storyboard instantiateViewControllerWithIdentifier:#"FlightDetails"];
NSLog(#"array: %#", pilotsArray);
NSString *AltitudeString = [[self.pilotsArray valueForKey:#"altitude"]objectAtIndex:indexPath.row]; <-----WIGS OUT HERE
I find this super odd as every other element works normally, but this one simply has issues. Any suggestions?
UPDATE:
NSLog of pilotsArray as per the request.
[1] LiveMap * 0x7f8b0265e1b0 0x00007f8b0265e1b0
altitude __NSCFString * #"21 ft" 0x00007f8b02664860
Also the jsonArray from the Service Directly.
Okay. I got it working. There was nothing wrong with the code. It however recognised another NSObject that had a same name "altitude" and for some reason it was getting mixed up.
I changed the name in the NSObject to something entirely unique and updated the instances in the relevant places. This did it. Lesson learnt always make sure you have named your variables appropriately.
I am trying to store user input text (in this case a book title) into an array so that I can output it in a table view in another xib.
I'm getting stuck trying to store the "bookTitle.text" info into my "userinfoArray". I know it probably has a simple solution and I know how to do it in C++ but not in Objective-C. Any tips, links etc. would be great.
NSMutableArray *userinfoArray = [[NSMutableArray alloc]init];
NSString *tempString = [[NSString alloc]initWithString:[bookTitle text]];
[userinfoArray addObject:tempString];
you can then access it later with:
[userinfoArray objectAtIndex:0];
NSMutableArray is very flexible. with addObject:object you can add as many things as you want, remove them with removeObjectAtIndex:index.
more here: NSMutableArray Class Reference
alternatively if you know what size your array will have you can use a normal NSArray: NSArray Class Reference which will work similar
sebastian
Try
userinfoArray = [NSArray arrayWithObject:[bookTitle text]];
Or if you want to create a longer array with more objetcs then
userinfoArray = [NSArray arrayWithObjects:[bookTitle text], secondObject, thirdObject, nil];
If you want to add or remove objects later then you may want to use NSMutableArray instead.
If this does not answer your question, then please try to be a bit more specific about your problem.
I'd like to add search functionality to a TableView in my app. I populate a table with an NSArray which has x amount of Objects that contain 3 NSStrings. Here's how I construct that NSArray:
First I create a class Code.h:
#import <Foundation/Foundation.h>
#interface Code : NSObject
#property (nonatomic, strong) NSString *codeName;
#property (nonatomic, strong) NSString *codeNumber;
#property (nonatomic, strong) NSString *codeDesc;
#end
Next, I synthesize these NSStrings in Code.m.
Now in my SearchViewController.m, Here's how I create my dataset:
NSMutableArray *codes;
codes = [[NSMutableArray alloc] init];
Code *c = [[Code alloc] init];
[c setCodeNumber:#"1"];
[c setCodeName:#"First Title Here"];
[c setCodeDesc:#"I might write a desc in here."];
[codes addObject:c];
c = [[Code alloc] init];
[c setCodeNumber:#"2"];
[c setCodeName:#"Second Title Here"];
[c setCodeDesc:#"2nd desc would be written here."];
[codes addObject:c];
and so on...
Here is how I display it: cellForRowAtIndexPath:
Code *c = [codes objectAtIndex:indexPath.row];
NSString *fused = [NSString stringWithFormat:#"%# - %#",[c codeNumber],[c codeName]];
cell.textLabel.text = fused;
return cell;
So now that you know how my data is structured and displayed, do you have an idea of how to search either the NSArray or possibly (preferably) the TableCells that have already been created?
I have been through the few tutorials online regarding Adding a Search Bar to a TableView, but all of them are written for using arrays setup using simple arrayWithObjects.
SIDETHOUGHT: Is it possible for me to construct an arrayWithObjects:#"aaa-1",#"bbb-2",#"ccc-3"... from my data? If i can manage that, I can use those tutorials to populate my cells and search them!
UPDATE:
Your second answer makes plenty more sense to me! Thanks for that. I beleive I have followed your instruction, but I am getting a "-[Code search:]: unrecognized selector sent to instance 0x6a2eb20` when that line is hit.
I added #property (nonatomic, strong) NSString *searchString; to Code.h and synthesized it in Code.m
I added NSMutableSet *searchResults; to SearchViewController.h's #interface
I added your methods performSearchWithString and matchFound to SearchViewController.m
Directly under those I added this to call performSearchWithString
x
- (void)searchBar:(UISearchBar *)theSearchBar textDidChange:(NSString *)searchString {
NSLog(#"%#",searchString); //Just making sure searchString is set
[self performSearchWithString:searchString];
[self.tableView reloadData];
}
The error hits when [codes makeObjectsPerformSelector:#selector(search:) withObject:self]; runs. I am confused b/c it sounds like Code doesn't recognize searchString, but I know I added it in Code.h.
UPDATE:
In order to store objects in searchResults, I had to change searchResults from a NSMutableSet to a NSMutableArray and modify - (void)matchFound:(Code *) matchingCode {} to this:
-(void) matchFound:(Code *) matchingCode {
Code *match = [[Code alloc] init];
if (searchResults.count == 0) {
searchResults = [[NSMutableArray alloc] init];
[match setCodeName:[matchingCode codeName]];
[match setCodeNumber:[matchingCode codeNumber]];
[match setCodeDesc:[matchingCode codeDesc]];
[searchResults addObject:match];
}
else
{
match = [[Code alloc] init];
[match setCodeName:[matchingCode codeName]];
[match setCodeNumber:[matchingCode codeNumber]];
[match setCodeDesc:[matchingCode codeDesc]];
[searchResults addObject:match];
}
With a few other tweeks, I've got a working searchbar for my tableView. Thanks Tim Kemp!
Oh, also case insensitive search was what I was looking for. NSRange rangeName = [codeName rangeOfString: searchString options:NSCaseInsensitiveSearch];
I hope this question and answer will be helpful to the next developer learning objective-c with this question!
Simpler approach
You asked for a simpler solution. This one isn't nearly as flexible, but it will achieve the same things as my earlier answer for this specific case.
Once again we are going to ask Code to search its strings for us. This time, we are going to skip the SearchRequest and the block callback and implement it directly.
In your SearchViewController you will create two methods. One to do the search, and one callback to process any results as they come back. You will also need a container to store matching Code objects (more than one might match, presumably.) You will also need to add a method to Code to tell it what the search string is.
Add an ivar NSMutableSet called searchResults to SearchViewController.
Add a property of type NSString * called searchString to Code
Add the search method to SearchViewController. This is what you'll call when you want to initiate a search across all your codes:
-(void) performSearchWithString:(NSString *) searchString {
// Tell each Code what string to search for
[codes makeObjectsPerformSelector:#selector(setSearchString:) withObject:searchString];
// Make each code perform the search
[codes makeObjectsPerformSelector:#selector(search:) withObject:self];
}
Then you will also need a callback in SearchViewController. This is so that your Code objects can tell the SearchViewController that they have found a match:
-(void) matchFound:(Code *) matchingCode {
[searchResults addObject:matchingCode];
// do something with the matching code. Add it to a different table
// view, or filter it or whatever you need it to do.
}
However do note that you don't have to use the searchResults mutable set; you may well want to just call another method to immediately add the returned result to some other list on screen. It depends on your app's needs.
In Code, add a search method a bit like we had before, but instead of the SearchRequest parameter we'll pass in a reference to the SearchViewController:
- (void) search:(SearchViewController *) searchVC {
// Search each string in turn
NSRange rangeNum = [codeNumber rangeOfString : searchString];
NSRange rangeName = [codeName rangeOfString : searchString];
NSRange rangeDesc = [codeDesc rangeOfString: searchString];
if (rangeNum.location != NSNotFound || rangeName.location != NSNotFound || rangeDesc.location != NSNotFound) {
[searchVC matchFound:self];
}
}
Do you see how that works? If there's a match in any of the strings (|| means 'or') then pass self (which means exactly what it sounds like: the current object that's running this code right now) back to a method in the view controller called searchVC. This is called a callback because we are "calling back" to the object which originally sent us the message to do the search. We have to use callbacks rather than simple return types because we have used makeObjectsPerformSelector to tell every single Code in the codes array to do a search. We never explicitly called the search method ourselves, so we have no way to capture the return value from each search. That's why its return type is void.
You can extend matchFound to take an additional parameter which identifies which string the match was in (i.e. çodeNumber, codeName or codeDesc.) Look into enums as one good approach to pass around that kind of data.
Hope that's bit simpler.
Here is a link to an excellent language introduction/tutorial which will eliminate much confusion.
EDIT In your last comment you said that searchResults was null. I said to add it as an ivar somewhere in SearchViewController. In your initialiser method for SearchViewController you should call
searchResults = [[NSMutableSet alloc] initWithCapacity:50]` // Choose some sensible number other than 50; enough to hold the likely number of matching Code objects.
Alternatively you could 'lazy initialise' it in matchFound:
- (void) matchFound:(Code *) matchingCode {
if (!searchResults)
searchResults = [[NSMutableSet alloc] initWithCapacity:50];
[searchResults addObject:matchingCode];
}
Though if you do this you should be aware that anywhere else you access searchResults may find that it's null if matchCode: has never previously been called.
Original, flexible and more complicated answer
I'm a little unclear as to what you're trying to do, so I'm going with your title, "Searching each string in each object of an array." In your case, your Codes have three strings and your array has multiple Codes. I assume that you need a way to tell the caller - the code that wants to do the search - which Code matches.
Here is one approach. There are easier ways but this technique is quite flexible. Broadly, we are going to make the Code object do the work of searching its own strings. We are then going to give the Code object the ability to tell the caller (i.e. the object that owns the codes array, presumably your table view controller) whether any of its strings match the search string. We will then use NSArray's method makeObjectsPerformSelector to have to tell all of its Code objects to search themselves. We will use a block for a callback.
Firstly, add a search method to Code (in the interface, or as a category depending on your design), something like this:
-(void) search:(SearchRequest *) request {
// Search using your favourite algorithm
// eg bool matches = [searchMe [request searchString]];
if (matches) {
[request foundMatch:self];
}
}
SearchRequest is new. It's a place to tie together a search string and a callback block. It looks something like this:
#interface SearchRequest
#property (retain) NSString * searchString;
#property (copy) void (^callback)(Code *);
- (id) initWithSearchString:(NSString *) search callback:(void (^)(Code *)) callback;
- (void) foundMatch:(Code *) matchingCode;
#end
#implementation SearchRequest
// synthesize...
// initialiser sets ivars
- (void) foundMatch:(Code *) matchingCode {
callback(matchingCode);
}
The callback block is our way of communicating back to the caller.
When you want to perform a search, construct a SeachRequest object with the string you're searching for and a block which contains the method to call when you get a match.
That would look like this, in the caller:
- (void) performASearchWithString:(NSString *) searchForMe {
SearchRequest * req = [[SearchRequest alloc] initWithSearchString:searchForMe
callback:^(Code * matchingCode) {
[self foundAHit:matchingCode];
}];
[codes makeObjectsPerformSelector:#selector(search:) withObject:req];
}
You then need to implement foundAHit in your caller, which takes the matching Code and does something with it. (You don't have to use a block: you could store a reference to the caller and a selector to call on it instead. I won't go into the arguments for either case here. Other answerers can propose alternatives.)
I have a simple object. It has several NSString properties (propertyA, propertyB, propertyC).
I have a string (read from a csv file) in the following form:
this is value A, this is value B, this is value C
another row A, another row B
Notice that the second row is missing the last property.
I want to parse the string into my object. Currently I'm grabbing a line from the csv file and then doing this:
MyObject *something = [[MyObject alloc] init];
NSArray *split = [line componentsSeparatedByString:#","];
if (something.count > 0)
something.propertyA = [split objectAtIndex:0];
if (something.count > 1)
something.propertyB = [split objectAtIndex:1];
if (something.count > 2)
something.propertyC = [split objectAtIndex:2];
This works well, but feels really horrible and hacky!
Has anyone got any suggestions for how I can improve the code?
Take a look at this tread about parsing CSV Where can I find a CSV to NSArray parser for Objective-C?
Dave DeLong wrote a CSV-parser library, you can find it here: https://github.com/davedelong/CHCSVParser
Hope this helps :)
Here's a CSV parsing extension to NSString that I used in the past to handle CSV data.
http://www.macresearch.org/cocoa-scientists-part-xxvi-parsing-csv-data
If basically adds a -(NSArray *)csvRows method to NSString that returns a NSArray with each row on your data and a NSArray inside each row to handle the columns.
It's the simplest and cleanest way I found so far to deal with the ocasional CSV data that comes up.
Your approach actually seems pretty sound, given the input format of the file, and assuming that no individual items actually contain a comma within themselves. As others have mentioned, CSV and/or custom flat files require custom solutions to get what you want from them.
If the approach above gets you the data you want, then I say use it. If it doesn't though, perhaps you can share the actual problem you're experiencing (ie, what data are you getting out, and what were you expecting?)
Consider using an array of keys that correspond to MyObject property names. For example:
NSString *propertyNames[] = { #"property1", #"property2", #"property3" };
NSArray *values = [line componentsSeparatedByString:#","];
NSArray *keys = [NSArray arrayWithObjects:propertyNames count:[values count]];
NSDictionary *dict = [NSDictionary dictionaryWithObjects:values forKeys:keys];
MyObject obj = [[MyObject alloc] init];
[obj setValuesForKeysWithDictionary:dict];
You could then consider adding an initWithDictionary: method to MyObject that calls setValuesForKeysWithDictionary. That would help streamline things a little further, allowing you to write the last two lines above as a single line:
MyObject obj = [[MyObject alloc] initWithDictionary:dict];
I've noticed that in order to do a search of a table, a copy of that data must be inserted to a search array.
E.g.
//Initialize the array.
listOfItems = [[NSMutableArray alloc] init];
NSArray *countriesToLiveInArray = [NSArray arrayWithObjects:#"Iceland", #"Greenland", #"Switzerland", #"Norway", #"New Zealand", #"Greece", #"Rome", #"Ireland", nil];
NSDictionary *countriesToLiveInDict = [NSDictionary dictionaryWithObject:countriesToLiveInArray forKey:#"Countries"];
NSArray *countriesLivedInArray = [NSArray arrayWithObjects:#"India", #"U.S.A", nil];
NSDictionary *countriesLivedInDict = [NSDictionary dictionaryWithObject:countriesLivedInArray forKey:#"Countries"];
[listOfItems addObject:countriesToLiveInDict];
[listOfItems addObject:countriesLivedInDict];
//Initialize the copy array.
copyListOfItems = [[NSMutableArray alloc] init];
So what is searched is the objects that are stored in the copied array.
My Question is, how do I search Cell rows with text, subtext and image in that particular cell.
(1)
There isn't really any such thing as searching a table. What happens when the user enters text in a UISearchBar is totally up to you - you can make that operation mean anything you like. All you have to do is function as the delegate-and-data-source for the results table and form the results table in response to the standard Three Big Questions that form the basis for any table ("how many sections have you? how many rows in this section? what's the cell for this row?") in any way you like. The results table does often look like a reduced version of the original table, but this is not at all required! It can be any table you want it to be.
(2)
Don't confuse Model with View. The table is just a view. Your data is Model. It is the Model, your data that is the basis of the original table, that you are going to be searching. So when the user types in your UISearchBar and you start searching, you want to form a new Model that will be the basis of the results table. How you form it is completely up to you. Typically you'll want to filter the original model so that the only stuff left in your results model is stuff that counts as a valid result. You could do this by walking the whole original model, putting everything that matches the search criterial into the new model. Or, if the original model is an array, you could use one of the filteredArray methods to help you. The most flexible way is to form a predicate with a block, as in this example from my book:
NSPredicate* p = [NSPredicate predicateWithBlock:
^BOOL(id obj, NSDictionary *d) {
NSString* s = obj;
NSStringCompareOptions options = NSCaseInsensitiveSearch;
return ([s rangeOfString:sbc.searchBar.text
options:options].location != NSNotFound);
}];
self.filteredStates = [states filteredArrayUsingPredicate:p];
In that example, s (one item of the array) is a string each time, and I'm looking to see whether the user's search term occurs in that string. But if you had a dictionary or other structure holding both a title and a subtitle and info about an image, you could examine that dictionary in any way you like. It's just a matter of returning YES or NO according to whether this array item passes the test based on the search term, on whatever definition you attach to the notion of passing the test.
(3)
The big question remaining is when to form the results model. I usually start by making the results model identical to the original model in response to searchDisplayControllerWillBeginSearch, because otherwise the results table will say No Results while the user is typing. (That is probably why you think the first thing to do is copy the original model.) Then, I can either do the actual filtering in response to searchBarSearchButtonClicked (the user is done typing and has tapped Search), or if the model is small enough, I can filter it afresh after every letter the user types, in response to searchBar:textDidChange (the user has typed a letter in the search bar).
There are a few steps involved. Note that the code below is just an example that I'm typing in by hand now, so it probably won't compile, it's just to give you an idea.
1) Ensure that you have an array containing all the cell values.
2) Create a copy of that array, and use that copy as the data source when returning cells in your table delegate methods.
3) Set yourself up as delegate for the UISearchBar, and respond to its events:
- (void)searchBarButtonClicked(UISearchBar *)searchBar {
[self doSearch:searchBar.text];
}
- (void)searchBar(UISearchBar *)searchBar textDidChange:(NSString *)searchTerm {
if (searchTerm.length == 0) {
[self resetSearch];
[table reloadData];
}
else
[self doSearch:searchTerm];
}
- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar {
searchBar.text = #"";
[self resetSearch];
[table reloadData];
[searchBar resignFirstResponder];
}
4) Create the other methods
The resetSearch method just needs to copy your full data array to the data source array used by your table delegates:
- (void)resetSearch {
self.tableSourceArray = [self.dataSourceArray copy]; // Or write a deep copy if you want to.
}
Whereas when searching, we need to filter the datasource array. You may be able to create something more efficient - this is just an example.
- (void)doSearch:(NSString *)searchTerm {
NSMutableArray *filtered = [[NSMutableArray alloc] init];
for (NSString *item in self.self.dataSourceArray) {
if ([item rangeOfString:searchTerm options:NSCaseInsensitiveSearch].location != NSNotFound])
[filtered addObject:[item copy]];
}
self.tableSourceArray = filtered;
}
And that should be it!
Tim