I know how to build and display the XML data in UITableView. And let's say I have an UITableView named: "DisplayData"
I have a same three XML documents. All three have same structure. Ex:
Doc1:<data><a>v1</a><a>v1</a></data>
Doc2:<data><a>vx</a><a>vx</a></data>
Doc3:<data><a>ZZZ</a><a>ZZZ</a></data>
What I want to do is - that when user selects a row from allready loaded UITableView - a new instance of same code is loaded onto stack of views.
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
DisplayData *o = [[DisplayData alloc] init];
o.rootElementName = #"data";
o.urlToLoad = self.urlToFolow;
o.urlToFolow = self.parsedURL;
[self.navigationController pushViewController:o animated:YES];
[o release];
}
So basically I want to load different data and detail data with only one UITableView.
You should keep your data in a model object (NSArray ?) and when the user taps on a row you replace the model object with the new data and call [tableView reloadData].
You can also have a look at Apple's Drill Down Table View example...
Related
So my situation is pretty unique. I have a to-do list app with a bunch of tasks. Each task has a UITableViewCell. After each table view cell is tapped, it creates a view controller with the task at that row's index path's property. These view controllers are all stored in a NSDictionary. This is the code representation of what I just said:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
DetailViewController *detailVC;
if (![self.detailViewsDictionary.allKeys containsObject:indexPath]){
detailVC = [[DetailViewController alloc]initWithNibName:#"DetailViewController" bundle:nil];
[self.detailViewsDictionary setObject:detailVC forKey:indexPath];
detailVC.context = self.managedObjectContext;
}else{
detailVC = self.detailViewsDictionary[indexPath];
}
Tasks *task = [[self fetchedResultsController] objectAtIndexPath:indexPath];
detailVC.testTask = task;
[[self navigationController] pushViewController:detailVC animated:YES];
NSLog(#"%#", self.detailViewsDictionary);
}
So this method of creating unique view controllers and storing them with a certain key almost always works. The problem arises when I delete or move the view controllers:
I was under the impression that a cell's index path gets recycled as you scroll down (dequeue). Doesn't that mean marking each cell with a number identifier would result in multiple cells for the same identifier?
Also, if you stored each view controller with a indexPath key, how do you make sure the key isn't set to two view controllers..? For example. Let's say you have 4 cells, which means 4 view controllers. You delete cell 3. Cell 4 moves down to cell 3s spot. You create a new cell which goes to spot 4. Now you have two controllers with the same indexPath key! How do you avoid this?? It's screwing up my app right now because tasks that have already been moved are loading their properties in the wrong view controller/cell!
I was suggested this to solve the problem before: "You maintain an NSMutableArray that "shadows" the contents of the table." However, I don't understand what this means/how to implement it.
You can use a technique we used to use on old databases. You store an NSInteger as a class var, and use that to assign a unique id to each of the cells as you create them. As you create each cell, you increment the unique id. Like this:
in your interface:
#property (nonatomic, assign) NSUInteger nextUniqueId;
then in - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
cell.tag = self.nextUniqueId++;
and then track those tags in your viewControllers. Just give them an assignable property, or customize the init to include the id.
Better to set the tag value for each row in cell for row at index path method.Store that tag value globally,and use that tag in did select row method.
Currently, I have a savedWorkout class that is simply a Table View populated with different exercises in each cell. My goal now is for the user to be able to click on each individual exercise, which will take you to a new view filled with detailed information about it.
For this, I have created an Exercise class that will hold the detailed information about the new object. Is this possible?
Here is some pseudo-code I have written up:
if (Table View Cell's Text == ExerciseObject.exerciseName) {
Populate a view with the corresponding information;
}
Being new to iPhone programming, I'm not exactly sure what would be the best way to do this, and this is what i'm thinking would be the best way to go about it.
My Exercise class holds an NSString to keep track of the exercise name, and three NSMutableArray's to hold different information.
Please let me know if I am going in the right direction.
EDIT:
After trying to implement my pseudo-code this is what I came up with:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
Exercise *exerciseView = [[Exercise alloc] initWithNibName:#"Exercise" bundle:nil]; //Makes new exercise object.
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
NSString *str = cell.textLabel.text; // Retrieves the string of the selected cell.
exerciseView.exerciseName.text = str;
[self presentModalViewController:exerciseView animated:YES];
}
However, this doesn't seem to work. When the new view is presented, the label doesn't show up (I connected the UILabel exerciseName to my desired string). Am I implementing this wrong?
Yes, of course it's possible. Just use the delegate method:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;
and check your data source cell based on the index location.
You might need to post your cellForRowAtIndexPath method. If done traditionally, it uses the indexPath.row to access an array of exercises to get a particular exercise, then changes cell properties based on the particular exercise. Is that about right?
It so, then you're halfway home.
EDIT
1) Use the code inside your cellForRowAtIndex path to init your str, as indicated here.
2) The new view controller view hasn't been built yet. You can't initialize a subview in the view hierarchy before the VC is ready. You need to pass the string to a property in that view controller (in a custom init method if you want), then on that class's viewDidLoad, you can set the exerciseName field to the string property you saved earlier. That subview shouldn't be part of the classes public interface.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// There should be an array of exercises, the same one used in cellForRowAtIndexPath:
NSString *str = [self.myArrayOfExercises objectAtIndex:indexPath.row];
// Just made code up here, but however you get a string to place in the cell
// in cellForRowAtIndexPath do that same thing here.
Exercise *exerciseView = [[Exercise alloc] initWithNibName:#"Exercise" bundle:nil];
// Might be wise to rename this ExerciseViewController, since it's probably (hopefully) a ViewController subclass
// no need to get a table cell, you have the info you need from your exercise array
//UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
//NSString *str = cell.textLabel.text; // Retrieves the string of the selected cell.
exerciseView.exerciseName.text = str;
[self presentModalViewController:exerciseView animated:YES];
}
I have an application in which I have tableview in which I return 3 rows in the tableview. When I select a particular row in the table view another tableview should open which should display list of items and when I select a particular item the value of that particular item should be set to the textlabel of previous tableview.
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
if (tableView != secondTableview) {
self.secondTableviewArray =[[NSMutableArray alloc]initWithObjects:#"secondfirst",#"secondSecond",nil];
[secondTableview reloadData];
}
}
Pass the second controller (the one that will appear) a weak reference to the first just before showing it. Once the second view controller has appeared and the user has made the selection (you can catch that in (-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;), send a message to the first giving the value selected.
The first view controller, then can store the new value, and even dismiss/pop the second.
This can also be achieved, by writing your own delegate protocol, so the first conforms to it, and is the delegate for the second.
Take NSString in second view and use the property.from the first view to second view set the string and in second view use that String
If you want to open new table view on click of row then you make new xib file and call like as define in below code:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[tableView deselectRowAtIndexPath:indexPath animated:NO];
XMLBooksViewController * xmlBooksViewController = [[XMLBooksViewController alloc] initWithNibName:#"DetailView" bundle:nil];
XMLBooksAppDelegate * appDelegate = [UIApplication sharedApplication].delegate;
xmlBooksViewController.author = [appDelegate.authors objectAtIndex:indexPath.row];
[self.navigationController pushViewController:xmlBooksViewController animated:YES];
[xmlBooksViewController release];
}
In next file you define another table view, so the list or items comes as table view.
I’m populating a UITableView based on the values of an NSMutableArray. This table view has search results. If the user clicks in one of the results, one will navigate to another screen. If the user clicks “back”, the search results are filled in again. At this point, while the table view is being repopulated, the old values still appear, just as I want. However, since I’m doing:
- (void)viewWillAppear:(BOOL)animated
{
NSMutableArray *m = [[NSMutableArray alloc] init];
self.searchResultsArray = m;
[m release];
}
The old cells information is no longer available. Thus, the app crashes if the user clicks in one of the old cells or scrolls the UITableView because I’m accessing the mutable array which was reinitialized above.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSArray *cellArray = [searchResultsArray objectAtIndex:indexPath.row];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
appDelegate.selectedCell = [searchResultsArray objectAtIndex:indexPath.row];
}
Do you have any suggestions concerning how should I do this properly?
Thanks.
this is because you are re-initalizing the array each time the view comes back in focus, the array will then have 0 objects in, causing the issue when you select a row and reference an index in the array that simply was wiped when the viewWillAppear is called.
why not init ' self.searchResultsArray ' in viewDidLoad (remembering to undo this with release when the device receives memory warning)
let me know how you get on.
You should reset the array only when the view loads:
- (void)viewDidLoad
{
[super viewDidLoad];
NSMutableArray *m = [[[NSMutableArray alloc] init] mutableCopy];
self.searchResultsArray = m;
[m release];
}
You should always call the reloadData: method when changing the data in the UITableViewDataSourceDelegate instance.
Let me know if this helps
Please try below code:
- (void)viewWillAppear:(BOOL)animated
{
// Your search result array with your old values
// Now add or appened new data to your old search results.
[self.searchResultsArray addObject:#"Your Value 1"];
[self.searchResultsArray addObject:#"Your Value 2"];
[self.searchResultsArray addObject:#"Your Value 3"];
[self.tableView reloadData];
// if you need to add new values from a array put this code in a loop.
}
It should helps you...
Thx
It seems to me that you are not initialising the NSArray in the right method (viewDidLoad:).
Using XLData you don't have to care about where you set up the storage, reload the UITableView or add items to the NSArray (searchResultsArray) since it keeps track of the data (NSArray) and updates the UITableView accordingly and on the fly.
I am currently writing my first iPhone app, but have encountered an issue. I have a view which contains a UITableView. This is the first time that I have attempted this, and this is the behaviour that I am trying to achieve:
When the user selects one of the rows, I would like this to call a new view, taking the user to a different page displaying info in reference to what they have selected.
I have it currently, so when the user selects a row it displays a UIAlert in the same view, but this doesn;t suit my needs. I have set the UITableView up through interface builder, and inputted the following code into my .m file to set it up.
- (NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section {
//return the value
return 10;
}
//now we define the cells.
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
// Identifier for retrieving reusable cells.
static NSString *cellIdentifier = #"MyCellIdentifier";
// Attempt to request the reusable cell.
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
// No cell available - create one
if(cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:cellIdentifier];
}
// Set the text of the cell to the row index.
cell.textLabel.text = [NSString stringWithFormat:#"iPad %d", indexPath.row];
return cell;
}
This creates a list of ten rows. The following codes gives me my UIAlert when tapped, however, I want to remove this and make it call a new view of my choice;
- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Show an alert with the index selected.
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:#"iPad Selected"
message:[NSString stringWithFormat:#"iPad %d", indexPath.row]
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
[alert release];
}
Can anyone help with this last piece of code? the view I want it to call is called 'ProteinView'.
Alrighty, what we need to do is use one of the UITableView methods that are already readily available to us. We'll do the following.
- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
ProteinView *detailViewController = [[ProteinView alloc] initWithNibName:#"ProteinView" bundle:nil];
// It is here we'd pass information from the currently selected UITableViewCell to the ProteinView.
// An example of this is the following.
// I would do it like this, but others would differ slightly.
NSString *titleString = [[[NSString alloc] initWithFormat:#"iPad %d",indexPath.row] autorelease];
// title is an object of detailViewController (ProteinView). In my own instances, I have always made a NSString which in viewDiDLoad is made the self.navigationBar.title string. Look below for what my ProteinView.m and .h would look like.
detailViewController.stringTitle = titleString;
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
EDIT
// -------- ProteinView.m -------- //
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
// Here we set the navigationItem.title to the stringTitle. stringTitle is declared in the .h. Think of it as a global scope variable. It is also propertised in the .h and then synthesized in the .m of ProteinView.
self.navigationItem.title = stringTitle;
}
I haven't compiled this, so I don't know if it'll fully work. But that is definitely the fastest and most easiest way to do it!
You could present the view modally like this
YourViewController2 *viewController2 = [[YourViewController2 alloc]initWithNibName:#"YourViewController2" bundle:nil];
[self presentModalViewController:viewController2 animated:YES];
Do you have more than one view to present? If so you will need to create an array with the names, pass it into the tableview and then present the correct view for the row selected based on the indexPath.row.
you'll have to open your MainWindow.xib and add a navigation controller to it. Then add a navigation controller outlet to your app delegate and connect them. Then you'll need to set the navigation controller's view as your main window's view.
You can add a table view to any iPhone app fairly easily, just by creating a new UITableViewController subclass from the File -> New command.
Even if you go this route, I would suggest creating a new navigation-based project to use as a template/cheat-sheet.