I want my table items to show the disclosure arrow and link to another "details" screen. Pretty standard. Three20 is supposed to help with this.
In my TTListDataSource, I'm currently doing:
- (void)tableViewDidLoadModel:(UITableView *)tableView
{
[super tableViewDidLoadModel:tableView];
// Construct an object that is suitable for the table view system
// from each domain object that we retrieve from the TTModel.
for (Listing *result in [(id<SearchResultsModel>)self.model results]) {
NSString *url = [NSString stringWithFormat:#"myapp://listing", result.theID];
TTTableSubtitleItem *item = [TTTableSubtitleItem itemWithText:result.title subtitle:result.desc imageURL:result.imageURL defaultImage:nil URL:url accessoryURL:nil];
[self.items addObject: item];
}
}
But I need to pass an object (not just a string) to the TTViewController when the TTTableItem is clicked. I know that you can pass an NSDictionary object to a
TTViewController using: TTNavigator's [[TTNavigator navigator] openURL: query: animated:] method.
However, since I'm trying to open this URL from a TTTableItem, I don't know how to use openURL method with it where I can pass a query NSDictionary object, since all it takes as an NSString "URL" parameter.
I read the discussion here however I'd really, really like to avoid having to modify the original Three20 code. If it can properly be extended, that would be fine.
What's the simplest way I can make my table item's open up a TTViewController and pass an object (such as an NSDictionary)?
If you look at http://three20.info/core/navigation they show you how to do this without overriding the didSelectObject method.
In a nutshell, you can assign a URL to an object (via a category for NSObject) which is mapped to a URL for the controller that is hosting the table. The handler can then open another URL passing the appropriate objects in the query dictionary.
From the Google Group...
http://groups.google.com/group/three20/msg/5cdbbaf753dc52a1
Related
I am trying to set up an object to control all of my data so it can set things up in the background to it appears my tableviews load faster than they do now etc.
This is what I am trying to achieve.
I am setting a variable in the NSObject from the secondVC when the tableviewcell is selected like this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
//Access selected cells content (cell.textLabel.text)
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
//Parent view logic (sends info back to the correct cell in parent view)
if (parentViewSelectedIndexPath.section == 0)
{
if (parentViewSelectedIndexPath.row == 0)
{
//Predicates restrict the values that will be returned from the query
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"%K like %#",#"MANUFACTURER",cell.textLabel.text];
NSArray *filterArray = [myDataArray filteredArrayUsingPredicate:predicate];
//[[self delegate] setManufactureSearchFields:filterArray withIndexPath:indexPath]; //This is where I pass the value back to the mainview
//Using Object
VehicleControllerNSObject *vehicleControllerNSObject = [[VehicleControllerNSObject alloc] init];
[vehicleControllerNSObject setFirstCell:filterArray];
}
//etc
At the end there you can see the method that is getting set up in the VechicleControllerNSObject which looks like this.
-(void)setFirstCell:(NSArray *)array{
manufactureSearchObjectStringFVC = [[array valueForKey:#"MANUFACTURER"] objectAtIndex:0];
NSLog(#"%#", manufactureSearchObjectStringFVC); // this prints the correct value to the console
}
As you can see this prints the correct output fine.
however I have no idea how to call manufactureSearchObjectStringFVC and pass the value it holds into the uitableviewcell that I would like to pass it in on my firstviewcontroller.
This is what I have for testing atm.
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
VehicleControllerNSObject *vehicleControllerNSObject = [[VehicleControllerNSObject alloc] init];
manufactureSearchObjectString = vehicleControllerNSObject.manufactureSearchObjectStringFVC;
NSLog(#"%#", vehicleControllerNSObject.manufactureSearchObjectStringFVC);
}
That nslog prints null..
I have three questions
1, how do I get the correct value into the first valuecontroller.
2, should I be using viewDidAppear like this?.. I think not.. how can I do this better
3, Do you think this is a good way of doing this type of thing, as in the future i would like to use the NSObjectClass to parse info, cache etc all behind the senses leaving the views to just display when the data is ready hopefully helping performance..
Any help would be hugely appreciated as I really want to learn this stuff as i know its important for me to know.
Your question is so beautifully and clearly formatted and diagrammed that it seems a shame to ask you to do a search. But here it is:
Search for Sharing Data between View Controllers
You'll find many good discussions about sharing data between view controllers.
Briefly, though, I can tell you why your code isn't working. In your tableView:didSelectRowAtIndexPath: method, you are creating (alloc/init) a new instance of your VehicleControllerNSObject class each time. Then back in your first view controller on viewDidAppear:, again you are creating (alloc/init) a whole new instance each time.
So you have multiple objects coming and going and they have nothing to do with each other. It's a bit like giving some important information to one person at a bus station and then later randomly picking some other person out and trying to retrieve that same information from her.
So one quick idea would be to create just once instance of your VehicleControllerNSObject (just an aside, that's a bit of a strange name for a class since generally all objective-c objects are descendants of NSObject anyway. I'm just going to call that VehicleController for now)
So let's say you wanted a 'sharedInstance' of VehicleController. You could add a class method to VehicleController to give you a way to easily get that one sharedInstance:
+(VehicleController*)sharedInstance {
static VehicleController *sharedInstance_ = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance_ = [[VehicleController alloc] init];
});
return sharedInstance_;
}
So to get that instance in methods in other classes you can just do something like :
VehicleController *sharedController = [VehicleController sharedInstance];
sharedController.someProperty = someValue;
// and then back in your first view controller, similarly:
VehicleController *sharedController = [VehicleController sharedInstance];
id someValue = sharedController.someProperty;
Again, check the search, many people have had good discussions on this. This is just one approach. I hope it at least makes sense why your code wasn't working.
Hope that helps.
To answer question 3. No.
I think that the best way to do something like this would be to use Core Data and it's NSManagedObject.
A combination of UITableViewController and NSFetchedResultsController that is feed from a Core Data sqlite backing store, if well set would feed and keep your UITableView updated.
It would be to long to describe all in here. So I will stop there.
If you don't want to go with that there is always the possibility to use a shared pointers to a mutable object or to use a singleton object to communicate information between UIViewController.
I am currently parsing some xml that looks like this
<Rows>
<Row MANUFACTURERID="76" MANUFACTURERNAME="Fondont" ISMANU="F" ISAUTO="F"/>
<Row MANUFACTURERID="18" MANUFACTURERNAME="Anti" ISMANU="T" ISAUTO="T"/>
</Rows>
I parse it so that there is an array of dictionaries (each dictionary has the four values of the Row in it).
I then pass ManufacturerName to my startSortingTheArray method like this
if (dataSetToParse == #"ICMfg") // ICMfg is a string passed to this view from the parent view cell selection enabling me to pass different data sets to this view
{
//Filter results (ISAUTO = T)
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"%K like %#",#"ISAUTO",#"T"];
NSArray *filteredArray = [myDataArray filteredArrayUsingPredicate:predicate];
//Passes Manufacturer strigs over to startSortingtheArray method
[self startSortingTheArray:[filteredArray valueForKey:#"MANUFACTURER"]];
}
So from here all of the ManufacturerNames are sent to my method as an array of strings. I then use this array to set up all of my sections / index-scroller. The method below shows how I am doing this.
//method to sort array and split for use with uitableview Index
- (IBAction)startSortingTheArray:(NSArray *)arrayData
{
//If you need to sort incoming array alphabetically use this line of code
//TODO: Check values coming in for capital letters and spaces etc
sortedArray = [arrayData sortedArrayUsingSelector:#selector(localizedCaseInsensitiveCompare:)];
//If you want the standard array use this code
//sortedArray = arrayData;
self.letterDictionary = [NSMutableDictionary dictionary];
sectionLetterArray = [[NSMutableArray alloc] init];
//Index scrolling Iterate over values for future use
for (NSString *value in sortedArray)
{
// Get the first letter and its associated array from the dictionary.
// If the dictionary does not exist create one and associate it with the letter.
NSString *firstLetter = [[value substringWithRange:NSMakeRange(0, 1)] uppercaseString]; //uppercaseString puts lowercase values with uppercase
NSMutableArray *arrayForLetter = [letterDictionary objectForKey:firstLetter];
if (arrayForLetter == nil)
{
arrayForLetter = [NSMutableArray array];
[letterDictionary setObject:arrayForLetter forKey:firstLetter];
[sectionLetterArray addObject:firstLetter]; // This will be used to set index scroller and section titles
}
// Add the value to the array for this letter
[arrayForLetter addObject:value];
}
//Reload data in table
[self.tableView reloadData];
}
from here I do several things to do with setting up the tableview after [self.tableView reloadData]; is called, The main thing being is that I set the cell up with the string values of the array.
//Display cells with data
NSArray *keys = [self.letterDictionary objectForKey:[self.sectionLetterArray objectAtIndex:indexPath.section]];
NSString *key = [keys objectAtIndex:indexPath.row];
cell.textLabel.text = key;
when the cell is then selected the string value inside the cell is then sent back to the main view and used later as a search parameter... The thing being is that I am setting up several parameters that will be used as one search string.
Looking back at the XML I parsed
<Rows>
<Row MANUFACTURERID="76" MANUFACTURERNAME="Fondont" ISMANU="F" ISAUTO="F"/>
<Row MANUFACTURERID="18" MANUFACTURERNAME="Anti" ISMANU="T" ISAUTO="T"/>
</Rows>
These are the values of columns inside an SQl table that has a keyvalue MANUFACTURERID that is also found in other tables that I parse. I would like to use these key values to restrict/refine other queries but I just cannot figure out how to pass them to my parentview where I set up all of the search parameters, that is my question how can I save the dictionary of values that is related to the users tableview selection from the subview. So that I can then pass one or some of those values back to the subview of a different dataset to restrict the information that is displayed dependent on the users previous selections.
This has taken me about an hour to type up. Hopefully it makes sense, I am still fairly new to iOS development and Objective C, and this concept is really pushing my capabilities and before I move on and end up hasing some crap together that I will have to fix later on I am hoping that one or some of you will be able to lend your experience in this type of this to me so I can get this right first time :)
If you need me to clarify anything or provide you more information that will help you help me just let me know.
Thanks in advance!
The common pattern for passing information backwards in your view controller hierarchy is to use delegation. You can achieve this in your scenario by implementing the following:
1) Define a protocol in the SearchParametersViewController, which represents your the parent view controller you mentioned.
#protocol SearchParametersViewControllerDelegate <NSObject>
#optional
- (void)searchOptionsSelected:(NSArray *)selectedSearchOptions;
#end
2) Conform to that protocol in your SearchOptionsSelectionViewController, which represents the table view controller that has a list of selections to choose from. Make sure to import or forward-declare the class the protocol is defined in (e.g. SearchParametersViewController) .
#import "SearchParametersViewController.h"
#interface SearchOptionsSelectionViewController <SearchParametersViewControllerDelegate>
3) Define a delegate property in your SearchOptionsSelectionViewController (assumes you are using ARC on iOS 5.0, 4.x use unsafe_unretained instead of weak. Use assign if the project is using manual memory management). This delegate object will contain a reference to your parent view controller (e.g. SearchParametersViewController). You do not want this property to be retained as to avoid retain cycles/circular references where one object references another, which in turn has a reference back to the first and neither object is ever deallocated.
#property (nonatomic, weak) id<SearchParametersViewControllerDelegate> delegate;
4) When instantiating the SearchOptionsSelectionViewController instance inside your parent view controller (SearchParametersViewController), set the delegate property to the parent view controller instance as represented by the self keyword. This ensures you can send the message (and corresponding data) backward in your view controller hierarchy, yet the object relationships remain loosely coupled. This delegate protocol could be conformed to in any other view controller, there are no tight relationships in the selection view controller back to the parent view controller, the only thing linking them is the flexible delegate protocol adoption by the selection view controller.
SearchOptionsSelectionViewController *selectionViewController = [[SearchOptionsSelectionViewController alloc] init];
selectionViewController.delegate = self;
5) Finally, in your SearchOptionsSelectionViewController table view's -tableView:didSelectRowAtIndexPath: delegate method, pass the data corresponding to the selected row back to your parent view controller (SearchParametersViewController) via the delegate method you defined in the SearchParametersViewControllerDelegate protocol. You must use the -respondsToSelector: method to ensure that the delegate object actually implements the -searchOptionsSelected: delegate method. To force this implementation, change #optional to #required above the method prototype in the protocol definition in step #1. self.someDataArray represents a the data source you are using with the selection table view controller. The specifics of the delegate protocol method and data object(s) sent back to the parent view controller can be changed, the important thing here is the delegation pattern and not having any tightly coupled relationships between the instances of either class, but especially backwards in the view controller hierarchy.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([self.delegate respondsToSelector:#selector(searchOptionsSelected:)])
{
NSArray *selectedObjs = [NSArray arrayWithObject:[self.someDataArray objectAtIndex:indexPath.row]];
[self.delegate searchOptionsSelected:selectedObjs]
}
}
6) Implement the delegate method inside SearchOptionsSelectionViewController.m
- (void)searchOptionsSelected:(NSArray *)selectedSearchOptions
{
// do what you need to with selectedSearchOptions array
}
Further reading:
Cocoa Fundamentals Guide - Delegates and Data Sources
Cocoa Core Competencies - Protocol
You could use the application delegate to achieve your goals here.
I'm going to assume your app has a structure a bit like this. Please excuse the crudity of this model.
Application delegate (A) --> Search Options View (B) --> Table where you do selections (C)
|
|
--> Some other view where you need the selection (D)
Your problem is that you need information to flow from C to D.
Your application delegate has the merit of being universally accessible via [[UIApplication sharedApplication] delegate]. So you can get a pointer to it from anywhere. From C, you can send your selection information back to A. A can either send this on automatically to D, or D can request it from A whenever it wants it.
A couple of points:
I won't expand any further on my answer at the moment because it's beer o' clock here now, plus I might have misunderstood your requirement. If you do need anything else, I will be up at baby o' clock in the morning UK time so there might be some delay.
Some people frown on using the application delegate as a "data dump" in the way I have suggested. Some of those people would rather set up a whole singleton class and treat that as a data dump instead. It seems to be one of those neverending arguments so I try not to get involved.
You have a few options, one is to use user defaults. It might be the easiest.
http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/Reference/Reference.html
Another is to post a notification with the information.
http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/nsnotificationcenter_Class/Reference/Reference.html
I have a function here that upon completing a single round, if your score is higher than either a default score entry or a newly placed high score then it will swap its data with your data and push everything else down. removing the last entry from the list. currently this is just one exchange and for functions sake I'm going to hard code it and then refactor it later.
My main problem is that when I set up a text input view to capture the players name execution continues immediately without the players input and crashes the game. I commented out the line that sets the text because I have a default value in place just in case any attempt that I try to make fails. How can I get Execution to wait for a moment while input is taken? Would I have to set up a delegate method? If so I'm still a bit confused by delegates. I could set it up to work but I don't understand it, so I wouldn't be able to do any other special custom tasks with it. I've worked on it for a while and got no further...
-(void)saveData:(ScoreKeep *)stats{
NSMutableDictionary *swap = [[NSMutableDictionary alloc]init];//used for swaping entries
NSString *filePath = [self pathOfFile];
NSLog(#"Writing to %#", filePath);
if ([[NSFileManager defaultManager]fileExistsAtPath:filePath]) {
NSLog(#"Loading previous dictionary to save...");
dataDictionary = [NSMutableDictionary dictionaryWithContentsOfFile:filePath];
if ([dataDictionary objectForKey:#"1"]) {
NSMutableDictionary *highScore = [dataDictionary objectForKey:#"1"];
if ([stats.score intValue] > [[highScore objectForKey:#"SCORE"] intValue]) {
NSLog(#"You Win! score: %# highscore: %#", stats.score,[NSNumber numberWithInt:[[highScore objectForKey:#"SCORE"] intValue]] );
stats = [[ScoreKeep alloc] initWithNibName:#"Scorekeep" bundle:nil];
NSLog(#"Setting up name entry");
[self.view addSubview:stats.view]; //New view is added so that the player can input data(Assume it is complete);
//stats.nameTag = setName.nameTag;//This line is executed before the new view is dismissed causing an error to occur
[stats setupDictionary]; // It just goes down hill from here if the previous line is uncommented
[dataDictionary setObject:stats.sComponents forKey:#"1"];
}else {
NSLog(#"You Lose: %# highscore: %#", stats.score,[NSNumber numberWithInt:[[highScore objectForKey:#"SCORE"] intValue]] );
}
NSLog(#"Got first place entry");
}else {
NSLog(#"Initilizing Score");
}
}else{
NSLog(#"Creating new dictionary to save...");
dataDictionary = [[NSMutableDictionary alloc]init];
}
[dataDictionary writeToFile:filePath atomically:YES];
}
Help would greatly be appreciated. If more information is needed I'd be happy to provide.
by the way ScoreKeep is an object that contains a dictionary and a function to create a dictionary such that it can set any values I need and package them into sComponents(the dictionary to be entered into the main savefile)
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#class omphalosUtility;
#pragma mark -
#pragma mark Saving data
#pragma mark -
static inline void poop(){
NSLog(#"POOP");
}
I'm going to try making a utility file that works independently of the app so that I Can update files and perform other universal operations such as saving when needed. Its a step in a direction that i'd like to take.
If i get it right, (The code is really nasty, man...) your problem is that you are trying to present a View Controller with the wrong way.
Correct me if i'm wrong, is ScoreKeep is a ViewController? if so, you have to name it properly. that's for a start.
Second, you cant present another view controller only by adding its "view" property to the current view controller's View Hierarchy. that way the view will not respond properly to the events.
the correct way to to what you'r trying to do is by presenting the ScoreKeep ViewController modally.
there is no other right way to do this without using delegation. you will have to acquire this technique.
Your view controller that responsible for getting the name from the user need to have a way to tell it's master view controller that the user entered a name. and that is achieved through delegation.
What you should do:
Basically you create a protocol called something like "NamePrompterViewControllerDelegate"
that will have at least one method that will be called when the user will done entering his name.
Your ScoreKeepViewController should have an instance variable that implemented the protocol (Look at the apple documentation on protocols for assistance)
Your main view controller (the one that contains the method you added) then should implement the protocol you created, and set itself as the delegate of ScoreKeep like that:
stats = [[ScoreKeep alloc] initWithNibName:#"Scorekeep" bundle:nil];
stats.delegate = self;
For more info on presenting and dismissing ViewControllers modally you should read the documentation at Apple Documentation
I hope i helped you, there is just a lot to cover and it hardly can be done by writing an answer.
Feel free to ask more for clearance.
I have a NSXMLParser that parses YT's API. It then turns all the videos into a class I wrote called video. Then the class is put into an array. Then back at my rootviewcontroller I access xmlParser.allVideos (xmlParser is a class I wrote that is the delegate for the xml parser.
Here is what I do with it in the viewDidLoad:
arrayFromXML = xmlParser.allVideos;
Then in the drawing of the tableView I do this:
tempVideo = [arrayFromXML objectAtIndex:indexPath.row];
cell.textLabel.text = tempVideo.videoTitle; //crashes here and says NSString has been deallocated.
How can I fix this?
If arrayFromXML is an instance variable you have to retain or copy (to be safe from later manipulation) the array as xmlParser simply might not be alive anymore when other methods are called later:
arrayFromXML = [xmlParser.allVideos copy];
Or better yet using a copy or retain property:
self.arrayFromXML = xmlParser.allVideos;
following situation:
in a TTTableViewController i added some Cells with URLs.
they are opening a class with #"tt://photos" for example. this works quite fine.
the first thing is, i saw some urls in TT Examples like #"tt/photos/1". is it possible to fetch this "1" in my photos class and say, for example okay, please open picture one, ore is this only another URL that was declared in TTNavigatior to open a specific Class?
the other thing is: is it possible to forward an object to the linked class?
clicking a cell opens #"tt://photos" (the linked class in my TTNavigator)
working with normal tableviews i can overwrite my init method and send an object with my initialize method, is this also possible by clicking my TTItems?
thanks!
figured it out myself, for those who need it:
First (passing "subURLs" in your navigator map)
navigating to an URL with #"tt://photos/firstphoto" is possible, you can fetch the "firstphoto" like this:
//Prepare your Navigator Map like this
[map from:#"tt://photos/(initWithNumber:)" toViewController:[PhotoVC class]];
In your PhotoVC you can access this Number:
-(void) initWithNumber: (NSString*)number {
NSLog(#"%#",number);
}
calling your View Controller with this url would look:
PhotoVC* controller = [[PhotoVC alloc] initWithNumber:#"1"];
[navigationController pushViewController:controller animated:YES];
[controller release];
Second (passing objects in an TTTableViewController)
its a bit tricky, but you dont have to Subclass anything.
first, nil the URL in the TableItem
[TTTableLink itemWithText:#"TTTableLink" URL:nil]
in your TTTableViewController write down this method
- (void)didSelectObject:(id)object atIndexPath:(NSIndexPath*)indexPath {
TTURLAction *urlAction = [[[TTURLAction alloc] initWithURLPath:#"tt://photos"] autorelease];
urlAction.query = [NSDictionary dictionaryWithObject:#"firstphoto" forKey:#"photo"];
urlAction.animated = YES;
[[TTNavigator navigator] openURLAction:urlAction];
}
now in your your PhotoVC you need something like this
- (id)initWithNavigatorURL:(NSURL*)URL query:(NSDictionary*)query {
if (self = [super init]) {
NSLog(#"%#",query);
}
return self;
}
and you are done ;)
I was trying to implement choise's answer, learned a lot, and eventually had to get the callouts showing up and keep the implementation with many urls simple, so here's what i did.
Keep URL in the TableItem,
Use this code in the TTTableViewController subclass.
- (void)didSelectObject:(id)object atIndexPath:(NSIndexPath*)indexPath {
NSLog(#"Its url is %#", [object URL]);
TTURLAction *urlAction = [[[TTURLAction alloc] initWithURLPath:(NSString *)[object URL]] autorelease];
urlAction.query = [NSDictionary dictionaryWithObject:self.user forKey:#"user"];
urlAction.animated = YES;
[[TTNavigator navigator] openURLAction:urlAction];
}
- (BOOL)shouldOpenURL:(NSString*)URL {
return NO;
}
That "shouldOpenURL:" was discovered looking through TTTableViewController, I tried it out, and it worked. Now the table view is not opening a duplicate view, and there are callouts!
Thanks choise!
Although choice's answer works for multiple params when u are creating the TTURLAction in code it is not very useful when u want to embed links to view controllers in your TTStyledLabel.One solution to that is to use multiple params in a single string.
<a href='app://view2/param1=value1¶m2=value2&...'>LabelName</a>
if you want the code to parse such urls and get the params please feel free to send me a message and I will send you my parser classes.
(or you can build your own with NSScanner!)
Also dont forget to escape the &s otherwise TTStyledLabel would not like it!
You don't need to run this on current version 1.0.6.2 for TTTableViewController. The "URL" option is working as expected. If it's not working for you, then your URL is broken or your are calling the wrong function on your ViewController. The function you have to call through URL must return an id (be a constructor for a ViewController) of a ViewController. Then it'll work as expected.
I'll changed the example form choise to be like TTNavigator expect it to be.
Add a mapping, which TTNavigator will use to navigate:
//Prepare your Navigator Map like this
[map from:#"tt://photos/(initWithNumber:)" toViewController:[PhotoVC class]];
Create a TTTableLink (or TTStyledText, or other) with an URL set, which should mach your map:
[TTTableLink itemWithText:#"TTTableLink" URL:#"tt://photos/1"]
Add this to your PhotoVC to be called by TTNavigator on the given URL
-(id) initWithNumber: (NSString*)number {
if (self = [super init]) {
self.title = #"Some Title";
NSLog(#"%#",number);
}
return self;
}
You don't need to overwrite the function didSelectObject, as the TTNavigator will call your ViewController through defined constructor function tt://photos/(initWithNumber:)