Hello and Thanks to All,
Here is the situation, When I use the following methode to populate my array it works when I use Methode 2 it does not work. The objective is to change the color of text. Both Methods have been NSLOGED and the data is identical.
First way..(working name gets grayed out)
-cellForRowAtIndexPath
....
if ([self.secArray containsObject:indexPath]) {
cell.textLabel.textColor = [UIColor grayColor];
} .....
-didSelectRowAtIndexPath:
...
[secArray addObject:indexPath];
Second Way (not working - populate the Array from my .plist )
-cellForRowAtIndexPath
....
if ([self.secArray containsObject:indexPath]) {
cell.textLabel.textColor = [UIColor grayColor];
} .....
-viewWillAppear
NSString *filePathOrdersIndex = [self dataFilePathOrders];
NSMutableArray *chekDist;
chekDist = [[NSMutableArray alloc] initWithContentsOfFile:filePathOrdersIndex];
NSLog( #"data checkDist........... %#", chekDist);
if(!chekDist){
chekDist = [[NSMutableArray alloc]init];
}
for(id dist_data in chekDist){
secArray = [dist_data objectForKey:#"myIndexPath"];
//[secArray addObject:[dist_data objectForKey:#"myIndexPath"]];
}
both methods logged to console both arrays contain Identical array data....but second way is not working
any help is greatly appreciated.
In the second method, you are assigning an element of the checkDist array to the array itself, is each dist_data in checkDist a secArray?
From an outside perspective, these two methods are not functionally equivalent without knowing more information about what kinds of data these variables hold. Though since you are setting the secArray variable each time the for loop executes, I'm assuming this is incorrect and you need to use the line you had commented-out in your second method ([secArray addObject:[dist_data objectForKey:#"myIndexPath"]];).
If after using that line instead it is still not working, verify that secArray has been created (make sure it's not nil) when the second method executes.
Related
Ok, so I am working with two sets of data that are extremely similar, and at the same time, these data sets are both global NSMutableArrays within the object.
data_set_one = [[NSMutableArray alloc] init];
data_set_two = [[NSMutableArray alloc] init];
Two new NSMutableArrays are loaded, which need to be added to the old, existing data. These Arrays are also global.
xml_dataset_one = [[NSMutableArray alloc] init];
xml_dataset_two = [[NSMutableArray alloc] init];
To reduce code duplication (and because these data sets are so similar) I wrote a void method within the class to handle the data combination process for both Arrays:
-(void)constructData:(NSMutableArray *)data fromDownloadArray:(NSMutableArray *)down withMatchSelector:(NSString *)sel_str
Now, I have a decent understanding of object oriented programming, so I was thinking that if I were to invoke the method with the global Arrays in the data like so...
[self constructData:data_set_one fromDownloadArray:xml_dataset_one withMatchSelector:#"id"];
Then the global NSMutableArrays (data_set_one) would reflect the changes that happen to "array" within the method. Sadly, this is not the case, data_set_one doesn't reflect the changes (ex: new objects within the Array) outside of the method.
Here is a code snippet of the problem
// data_set_one is empty
// xml_dataset_one has a few objects
[constructData:(NSMutableArray *)data_set_one fromDownloadArray:(NSMutableArray *)xml_dataset_one withMatchSelector:(NSString *)#"id"];
// data_set_one should now be xml_dataset_one, but when echoed to screen, it appears to remain empty
And here is the gist of the code for the method, any help is appreciated.
-(void)constructData:(NSMutableArray *)data fromDownloadArray:(NSMutableArray *)down withMatchSelector:(NSString *)sel_str {
if ([data count] == 0) {
data = down; // set data equal to downloaded data
} else if ([down count] == 0) {
// download yields no results, do nothing
} else {
// combine the two arrays here
}
}
This project is not ARC enabled.
Thanks for the help guys!
Rob
If I understood your problem, you are trying to pass your object as call-by-reference and hoping to work as in C++/C. But Obj-C, although similar but has some different way. You have to dereference the object by using ** (double pointer) as mostly seen in NSError case, which is very rare.
Second ways is: wrap method as a block. Then put the variable in the same lexical scope as the block, and denote it by __block storage type.
Third way can be accessing your object directly by making it an ivar/property or even an singleton.
Brand new to coding; been utilizing stackoverflow religiously for months; first time asking a question; please be gentle.
I'm trying to create a series of UITextFields programmatically using a for loop. The fields should have names like "pax1name", "pax2name", "pax3name", etc.
The piece I'm missing is how to take a string and make it the name of a textField, changing the name of the textField each time the for-loop executes.
Here's my code, but maybe I'm going about this the wrong way? Thank you in advance!
// set up the names textfields
for (int i = 0; i < 7; i++) {
NSString *fieldName = [[NSString alloc] initWithFormat:#"pax%iname", (i + 1)];
// I can't figure out what goes here to create a UITextField with the name of fieldName
textField = [[UITextField alloc] initWithFrame:CGRectMake(15, (15 + (i * 40)), 400, 40)];
textField.borderStyle = UITextBorderStyleRoundedRect;
textField.font = [UIFont systemFontOfSize:15.0];
textField.autocorrectionType = UITextAutocorrectionTypeNo;
textField.clearButtonMode = UITextFieldViewModeWhileEditing;
textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
[namesViewController addSubview: textField];
[fieldName release];
[textField release];
}
Normally you use the UIView property tag for that. Use [textField setTag:<youCustomTag>] in your loop to set the value, e.g. your variable i. Please note that tag expect an NSUInteger and not an NSString.
To access the correct text field afterwards you'd call [[namesViewController view] viewWithTag:<yourCustomTag>].
BUT, is it really necessary to create multiple text fields for your view controller? There might be a more elegant solution by creating just one single text field and setting the tag-property on demand when the user taps a row. I don't know if that would work for you.
I think you've been going the wrong way about this. UITextField has no property called "name". To identify a control, you can use its tag property. See this code:
for (int i = 0; i < 7; i++) {
UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(...)];
textField.tag = i + 1;
...
}
When you say the name of the textfield I'm presuming you mean the variable name rather than setting the text that is displayed. I.e. you want to create the variables in a loop, but later be able to reference them individually by name.
In that case, you can't do what you want to do. What you can do is stick them in an array for handy access later on.
NSMutableArray *paxNameFields = [[NSMutableArray alloc] init]; // before your loop
[paxNameFields addObject: textField]; // inside the loop
[paxNameFields objectAtIndex: 5]; //sometime later use the 6th field
Or if you just want to be able to identify which UITextField you're passed into a delegate callback later on, you can set/check the tag property.
UITextFields don't HAVE names. You're probably coming from HTML-world, where these things are basically a big hash of name-value pairs. Not like that in Cocoa Touch. As #Florian Mielke says, they each have an int .tag property, which is probably what you want to set.
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
Hey! I've been trying to add an array to an NSMutableArray using the addObject syntax. The app crashes without any explicit mention of an error. Could you please tell me how this is done?
I have a class Stack that creates an array. So I call that class using an instance called tem that I have created. Hence, [self tem] is my call to the array. Through the program I merely add UILabels to the array(I know you'd suggest adding a string and then changing to UILabels, but I need to do it this way) and towards the end, I'd like to add this array to my 'list' array.
-(Stack *)tem {
if(!tem)
tem=[[Stack alloc]init];
return tem;
}
-(void)viewDidLoad{
//code
list=[NSMutableArray arrayWithArray:[self list].array];
}
-(IBAction)opPr:(UIButton *)sender
{
if([[[sender titleLabel]text] compare: #"="]==0) {
//code
UILabel *t=[[UILabel alloc]init];
//complete creating label
[[self tem]push:t];
//add above label to tem array
[list addObject:[self tem].array];
[table reloadData];
}
}
OK, this answer got all cluttered with edits. I've edited it to be more clear, at the possible expense of understanding the thread of how we arrived at the final answer.
The final answer
The answer was to change:
list=[NSMutableArray arrayWithArray:[self list].array];
To:
list = [[NSMutableArray alloc] init];
(...Which isn't really the best way to create an NSMutableArray, but it may work anyway.)
This was based on an erroneous version of the asker's code
Based on your comment that it crashes after [list addObject:[self tem].array];, I must conclude that your instance variable list is of type Stack*, and that Stack is not a subclass of NSMutableArray. If so, that's your issue.
In that case, changing that line to [[list array] addObject:[self tem].array]; should fix it.
This is just good advice
As an aside, NSMutable array is perfectly capable of acting as a stack without modification. Example:
NSMutableArray* ar = [NSMutableArray arrayWithCapacity:someCapacity];
// Push
[ar addObject:narf]; // narf being some object reference
// Pop
id popped = [ar lastObject];
[ar removeLastObject];
If you want to encapsulate stack behavior in a semantically consistent way, you can add push and pop methods to NSMutableArray using a category. This would make your code simpler and less prone to error.
This was my first stab at answering the question, before any code had been posted
This is a stab in the dark since you've not posted any code. BUT. One way to accomplish that with arrays is by creating arrays using [NSArray arrayWithObjects:obj obj ... nil] and omitting the nil terminator on the list of objects. Are you by any chance doing that?
I had a navigation application that was working normally. In the table view, the last item is called "add item", and if the user pressed it, it would create a new object and pass it to another view where the user could enter the details for that object. When the user returned to the previous screen, the new object would show in the array which was displayed in the table.
I changed it so that the "add item" field is always the first field in the table, not the last. I made the appropriate changes so that the array would display correctly on the table. However, now I am noticing strange behavior.
If I edit the first object in the array, the 7th object also changes to be the same as this object. If I edit the second object in the array, the fourth and sixth object also change to be the same. If I edit the third item in the array, the fifth object changes to be the same.
What could be happening?
In the viewDidLoad: method I initialize the object like this:
PersonDetails *personDetails = [[PersonDetails alloc] init];
This is the method that gets executed when a user selects a row on the table
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Navigation logic may go here. Create and push another view controller.
updatePersonArray = YES;
arrayIndex = indexPath.row-1;
editPerson = [[EditClassController alloc] initWithNibName:#"EditPerson" bundle:nil];
editPerson.title = #"Edit Person";
if (arrayIndex != -1) {
personDetails = [classArray objectAtIndex:arrayIndex];
}
else {
personDetails = [[PersonDetails alloc] init];
}
editPerson.personDetails = personDetails;
[self.navigationController pushViewController:editPerson animated:YES];
[editPerson release];
}
This is what the viewWillAppear looks like. It will update the table after an object has been edited.
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
if ([personDetails isEmpty]) {
updatePersonArray = NO;
}
if (updatePersonArray) {
if (arrayIndex == -1) {
NSLog(#"adding new object to array");
[personArray addObject:personDetails];
}
else {
NSLog(#"replacing object at index %d", arrayIndex);
[personArray replaceObjectAtIndex:arrayIndex withObject:personDetails];
}
[self saveArrayToDisk];
[self.tableView reloadData];
updatePersonArray = NO;
}
else {
//load the array from disk
NSLog(#"loading array from disk");
NSData *theData = [[NSUserDefaults standardUserDefaults] objectForKey:#"personArray"];
if (theData != nil) {
NSLog(#"found something");
personArray = [[NSMutableArray alloc] initWithArray:[NSKeyedUnarchiver unarchiveObjectWithData:theData]];
}
else {
personArray = [[NSMutableArray alloc] init];
}
}
}
Edit: I solve the problem by implementing NSCopy for the person object and then making a copy of the object from the array instead of directly pointing to the object in the array. Anyone know why this solved the problem?
Edit: I solve the problem by
implementing NSCopy for the person
object and then making a copy of the
object from the array instead of
directly pointing to the object in the
array. Anyone know why this solved the
problem?
The original problem was pretty much guaranteed to be an issue of having the same PersonDetails in the array multiple times. If you were to do something like:
for (id p in myArray) NSLog("%p", p);
I'd bet that some of the addresses would be the same, indicating same object in array multiple times.
Which is why copying the object "fixed" the problem. You are hiding the dodgy logic that led to the above situation by making a copy on every insertion.
this part here looks a bit dodgy with regard to memory ownership:
if (arrayIndex != -1) {
// here you get back an autorelease object - which you haven't retained
personDetails = [classArray objectAtIndex:arrayIndex];
}
else {
// here you create an object with retainCount =1
personDetails = [[PersonDetails alloc] init];
}
// depending on your property attribute this may or may not work as you expect
editPerson.personDetails = personDetails;
i.e. #property(??) personDetails