initialLayoutAttributesForAppearingItemAtIndexPath fired for all visible cells, not just inserted cells - ios6

Has anyone seen a decent answer to this problem?
initialLayoutAttributesForAppearingItemAtIndexPath seems to be being called for all visible cells, not just the cell being inserted. According to Apple's own docs:
For moved items, the collection view uses the standard methods to retrieve the item’s updated layout attributes. For items being inserted or deleted, the collection view calls some different methods, which you should override to provide the appropriate layout information
Which doesn't sound like what is happening... the other cells aren't being inserted, they are being moved, but it's calling initialLayoutAttributesForAppearingItemAtIndexPath for the ones being moved too.
I have seen work arounds using prepareForCollectionViewUpdates: to trace which indexPaths are being updated and only changing those, but this seems a bit odd that it's going agains their own docs. Has anyone else found a better way around this?

I found this blog post by Mark Pospesel to be helpful.
The author also fixed WWDC CircleLayout sample and posted it on Github.
Methods of interest:
- (void)prepareForCollectionViewUpdates:(NSArray *)updateItems
{
// Keep track of insert and delete index paths
[super prepareForCollectionViewUpdates:updateItems];
self.deleteIndexPaths = [NSMutableArray array];
self.insertIndexPaths = [NSMutableArray array];
for (UICollectionViewUpdateItem *update in updateItems)
{
if (update.updateAction == UICollectionUpdateActionDelete)
{
[self.deleteIndexPaths addObject:update.indexPathBeforeUpdate];
}
else if (update.updateAction == UICollectionUpdateActionInsert)
{
[self.insertIndexPaths addObject:update.indexPathAfterUpdate];
}
}
}
- (void)finalizeCollectionViewUpdates
{
[super finalizeCollectionViewUpdates];
// release the insert and delete index paths
self.deleteIndexPaths = nil;
self.insertIndexPaths = nil;
}
// Note: name of method changed
// Also this gets called for all visible cells (not just the inserted ones) and
// even gets called when deleting cells!
- (UICollectionViewLayoutAttributes *)initialLayoutAttributesForAppearingItemAtIndexPath:(NSIndexPath *)itemIndexPath
{
// Must call super
UICollectionViewLayoutAttributes *attributes = [super initialLayoutAttributesForAppearingItemAtIndexPath:itemIndexPath];
if ([self.insertIndexPaths containsObject:itemIndexPath])
{
// only change attributes on inserted cells
if (!attributes)
attributes = [self layoutAttributesForItemAtIndexPath:itemIndexPath];
// Configure attributes ...
attributes.alpha = 0.0;
attributes.center = CGPointMake(_center.x, _center.y);
}
return attributes;
}
// Note: name of method changed
// Also this gets called for all visible cells (not just the deleted ones) and
// even gets called when inserting cells!
- (UICollectionViewLayoutAttributes *)finalLayoutAttributesForDisappearingItemAtIndexPath:(NSIndexPath *)itemIndexPath
{
// So far, calling super hasn't been strictly necessary here, but leaving it in
// for good measure
UICollectionViewLayoutAttributes *attributes = [super finalLayoutAttributesForDisappearingItemAtIndexPath:itemIndexPath];
if ([self.deleteIndexPaths containsObject:itemIndexPath])
{
// only change attributes on deleted cells
if (!attributes)
attributes = [self layoutAttributesForItemAtIndexPath:itemIndexPath];
// Configure attributes ...
attributes.alpha = 0.0;
attributes.center = CGPointMake(_center.x, _center.y);
attributes.transform3D = CATransform3DMakeScale(0.1, 0.1, 1.0);
}
return attributes;
}

You're not alone. The UICollectionViewLayout header file comments make things a little clearer.
For each element on screen before the invalidation,
finalLayoutAttributesForDisappearingXXX will be called and an
animation setup from what is on screen to those final attributes.
For each element on screen after the invalidation,
initialLayoutAttributesForAppearingXXX will be called an an animation
setup from those initial attributes to what ends up on screen.
Basically finalLayoutAttributesForDisappearingItemAtIndexPath is called for each item on screen before the animation block starts, and initialLayoutAttributesForAppearingItemAtIndexPath is called for each item after the animation block ends. It's up to you to cache the array of UICollectionViewUpdateItem objects sent in prepareForCollectionViewUpdates so you know how to setup the initial and final attributes. In my case I cached the previous layout rectangles in prepareLayout so I knew the correct initial positions to use.
One thing that stumped me for a while is you should use super's implementation of initialLayoutAttributesForAppearingItemAtIndexPath and modify the attributes it returns. I was just calling layoutAttributesForItemAtIndexPath in my implementation, and animations weren't working because the layout positions were different.

If you've subclassed UICollectionViewFlowLayout, you can call the super implementation. Once you've got the default initial layout, you can check for an .alpha of 0. If alpha is anything other than 0, the cell is being moved, if it's 0 it's being inserted.
Bit of a hack, I know, but it works 👍.
Swift 2.0 implementation follows:
override func initialLayoutAttributesForAppearingItemAtIndexPath(itemIndexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? {
guard let attributes = super.initialLayoutAttributesForAppearingItemAtIndexPath(itemIndexPath) where attributes.alpha == 0 else {
return nil
}
// modify attributes for insertion here
return attributes
}

Make sure you're using new method signature in Swift 3. Autocorrection doesn't work for this method:
func initialLayoutAttributesForAppearingItem(at itemIndexPath: IndexPath) -> UICollectionViewLayoutAttributes?

Related

Xceed DataGrid: Filtering Details

I've got a Master/Detail DataGrid and I want to filter the details.
Here's my DataGridCollectionViewSource:
<xcdg:DataGridCollectionViewSource x:Key="Features"
Filter="ExampleFilter"
Source="{Binding Path=ItemUnderEdit.Features}"
AutoCreateDetailDescriptions="False"
AutoCreateItemProperties="False">
<xcdg:DataGridCollectionViewSource.DetailDescriptions>
<xcdg:PropertyDetailDescription RelationName="Settings"
AutoCreateDetailDescriptions="False"
AutoCreateItemProperties="False">
</xcdg:PropertyDetailDescription>
</xcdg:DataGridCollectionViewSource.DetailDescriptions>
</xcdg:DataGridCollectionViewSource>
As you can see I'm filtering it with ExampleFilter, but this only filters the master. I put a breakpoint and it never sees any details.
I cant add a filter to the Detail Descriptions in the same way. Is there any way to filter the details? Any help would be much appreciated!
I went up against this problem today - I had a simple filter for both the master and detail sections that gets turned on / off via code. For the master section, it was a simple matter of code like:
((DataGridCollectionView)grid.ItemsSource).FilterCriteriaMode = FilterCriteriaMode.None; // Off
((DataGridCollectionView)grid.ItemsSource).FilterCriteriaMode = FilterCriteriaMode.And; // On
((DataGridCollectionView)grid.ItemsSource).Refresh(); // Re-run filter.
For the details section, it should have been as simple as the following code (it wasn't though):
MyDetailDescription.FilterCriteriaMode = FilterCriteriaMode.None; // Off
MyDetailDescription.FilterCriteriaMode = FilterCriteriaMode.And; // On
Turns out, doing that will enable the new filter for any new detail sections that get generated, but not existing ones. New detail sections are generated when the master row is expanded. To get around this it turned out I needed a simple foreach loop such as:
foreach (DataGridContext context in grid.GetChildContexts()) {
((DataGridCollectionViewBase)(context.Items)).FilterCriteriaMode = PetsDetailDescriptions.FilterCriteriaMode;
}
Here's my complete(ish) code for all that:
public bool ShowDeleted {
set {
if ((grid.ItemsSource != null) && (grid.ItemsSource.GetType() == DataGridCollectionView));
DataGridCollectionView v = ((DataGridCollectionView)(grid.ItemsSource));
if (value) {
v.FilterCriteriaMode = FilterCriteriaMode.None;
MyDetailDescription.FilterCriteriaMode = FilterCriteriaMode.None;
}
else {
v.FilterCriteriaMode = FilterCriteriaMode.And;
MyDetailDescription.FilterCriteriaMode = FilterCriteriaMode.And;
}
foreach (DataGridContext context in grid.GetChildContexts()) {
((DataGridCollectionViewBase)(context.Items)).FilterCriteriaMode = PetsDetailDescriptions.FilterCriteriaMode;
}
v.Refresh();
}
}
}
I'm using that in-conjunction with a simple predefined filter criterion in the XAML. IE:
<g:DataGridItemProperty Name="IsDeleted"
DataType="{x:Type sys:Boolean}">
<g:DataGridItemProperty.FilterCriterion>
<g:EqualToFilterCriterion>
<sys:Boolean>False</sys:Boolean>
</g:EqualToFilterCriterion>
</g:DataGridItemProperty.FilterCriterion>
</g:DataGridItemProperty>
I recommend using the Xaml FilterCriterions, because if you absolutely need the Filter event, it's going to get a bit more messy. For that route, you need to do the following steps:
Tap into the event when a new child DataGridContext is added to the control.
Add a predicate reference to the context.Items.Filter property (in the code state, this is a property expecting predicate, not an event).
Write your filter code in the predicate function.
I'm not 100% sure how to achieve #1 above (as I didn't need to go that route). However, a good place to possible start is the DetailsExpanding and DetailsExpanded events of the DataGridControl. For the expanding, I'm not sure if the child DataGridContext exists yet (as there is an option to cancel the expanding). So you might have to wait until after the expanded event.
I hope this helps point you in the right direction.

Reload UICollectionView header or footer?

I have some data that is fetched in another thread that updates a UICollectionView's header. However, I've not found an efficient way of reloading a supplementary view such as a header or footer.
I can call collectionView reloadSections:, but this reloads the entire section which is unnecessary. collectionView reloadItemsAtIndexPaths: only seems to target cells (not supplementary views). And calling setNeedsDisplay on the header itself doesn't appear to work either. Am I missing something?
You can also use (the lazy way)
collectionView.collectionViewLayout.invalidateLayout() // swift
[[_collectionView collectionViewLayout] invalidateLayout] // objc
More complex would be to provide a context
collectionView.collectionViewLayout.invalidateLayout(with: context) // swift
[[_collectionView collectionViewLayout] invalidateLayoutWithContext:context] // objc
You can then make a or configure the context yourself to inform about what should be updated see: UICollectionViewLayoutInvalidationContext
It has a function in there that you can override:
invalidateSupplementaryElements(ofKind:at:) // swift
Another option is (if you have already loaded the correct header/footer/supplementary view) and you only want to update the view with the new data than you can use one of the following functions to retrieve it:
supplementaryView(forElementKind:at:) // get specific one
visibleSupplementaryViews(ofKind:) // all visible ones
Same goes for visible cells with visibleCells. The advantage of just getting the view and not reloading a view entirely is that the cells retains it state. This is espically nice with table view cells when they use swipe to delete/edit/etc since that state is lost after reloading the cell.
If you feel fanatic you can of course also write some extensions to retrieve only cells/supplementary views of a given kind using generics
if let view = supplementaryView(forType: MySupplementaryView.self, at: indexPath) {
configure(view, at indexPath)
}
this assumes that you have a function that registers/dequeues views in example with their class name. I made a post about this here
I just ran into the same problem, and I ended up looking up the view using its tag to edit a label:
UICollectionReusableView *footer = (UICollectionReusableView*)[self.collectionView viewWithTag:999];
UILabel *footerLabel = (UILabel*)[footer viewWithTag:100];
Like you said it is unnecessary to reload an entire section, which cancels out any animation on cells as well. My solution isn't ideal, but it's easy enough.
Swift 3/4/5 version:
collectionView.collectionViewLayout.invalidateLayout()
Caution!
If you change the number of collectionView items at the same time (for example you show the footer only if all cells were loaded), it will crash. You need to reload the data first, to make sure that the number of items is the same before and after invalidateLayout():
collectionView.reloadData()
collectionView.collectionViewLayout.invalidateLayout()
I got the same problem. I tried #BobVorks's answer and it is working fine, if only the cell was reused else it won't. So, I tried finding a more cleaner way to achieve this and I came up reloading the whole UICollectionView after the performBatchUpdate (completion block) and it is working great. It reloads the Collection Without any cancellation of animation in the insertItemsAtIndexPath. Actually I personally up voted recent 2 answers cause i find it working but in my case, this is the cleanest way to do it.
[self.collectionView performBatchUpdates:^{
// perform indexpaths insertion
} completion:^(BOOL finished) {
[self.collectionView reloadData];
}];
[UIView performWithoutAnimation:^{
[self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:4]];
}];
[UIView performWithoutAnimation:^{
[self.collectionView reloadData];
}];
Here are two ways you could do it.
1.
Create a mutable model to back the data that will eventually be available. Use KVO in inherited class of UICollectionReusableView to observe the changes and update the header view with the new data as it comes available.
[model addObserver:headerView
forKeyPath:#"path_To_Header_Data_I_care_about"
options:(NSKeyValueObservingOptionNew |
NSKeyValueObservingOptionOld)
context:NULL];
then implement listener method in header view
- (void)observeValueForKeyPath:(NSString *)keyPath
ofObject:(id)object
change:(NSDictionary *)change
context:(void *)context
2.
add notification listener to the view and post a notification when the data has successfully come available. Downside is that this is application wide and not a clean design.
// place in shared header file
#define HEADER_DATA_AVAILABLE #"Header Data Available Notification Name"
// object can contain userData property which could hole data needed.
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(headerDataAvailable:) name:HEADER_DATA_AVAILABLE object:nil];
[[NSNotificationCenter defaultCenter] postNotificationName:HEADER_DATA_AVAILABLE object:nil];
let headerView = collectionView.visibleSupplementaryViews(ofKind: UICollectionView.elementKindSectionHeader)[0] as! UICollectionReusableView
I've used above method to get current header, and successfully updated subviews on it.
Here's what I did to update only the section headers that are currently loaded in memory:
Add a weakToStrong NSMapTable. When you create a header, add the header as the weakly held key, with the indexPath object. If we reuse the header we'll update the indexPath.
When you need to update the headers, you can now enumerate the objects/keys from the NSMapTable as needed.
#interface YourCVController ()
#property (nonatomic, strong) NSMapTable *sectionHeaders;
#end
#implementation YourCVContoller
- (void)viewDidLoad {
[super viewDidLoad];
// This will weakly hold on to the KEYS and strongly hold on to the OBJECTS
// keys == HeaderView, object == indexPath
self.sectionHeaders = [NSMapTable weakToStrongObjectsMapTable];
}
// Creating a Header. Shove it into our map so we can update on the fly
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
PresentationSectionHeader *header = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:#"presentationHeader" forIndexPath:indexPath];
// Shove data into header here
...
// Use header as our weak key. If it goes away we don't care about it
// Set indexPath as object so we can easily find our indexPath if we need it
[self.sectionHeaders setObject:indexPath forKey:header];
return header;
}
// Update Received, need to update our headers
- (void) updateHeaders {
NSEnumerator *enumerator = self.sectionHeaders.keyEnumerator;
PresentationSectionHeader *header = nil;
while ((header = enumerator.nextObject)) {
// Update the header as needed here
NSIndexPath *indexPath = [self.sectionHeaders objectForKey:header];
}
}
#end
This question is very old but a simple way to do it is to just set a delay that covers the time your view is animating and disabling the animation while you update the view...usually a delete or insert takes about .35 seconds so just do:
delay(0.35){
UIView.performWithoutAnimation{
self.collectionView.reloadSections(NSIndexSet(index: 1))
}
My problem arose when frame sizes for the supplementary views changed upon invalidating the layout. It appeared that the supplementary views were not refreshing. It turns out they were, but I was building the UICollectionReusableView objects programmatically, and I was not removing the old UILabel subviews. So when the collection view dequeued each header view, the UILabels would pile up, causing erratic appearance.
The solution was to build each UICollectionReusableView completely inside the viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath method, starting by a) removing all subviews from the dequeued cell, then b) getting the frame size from the item's layout attributes to allow adding the new subviews.
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
yourClass *header = (yourClass *)[collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:#"identifier" forIndexPath:indexPath];
[[header viewWithTag:1] removeFromSuperview]; // remove additional subviews as required
UICollectionViewLayoutAttributes *attributes = [collectionView layoutAttributesForSupplementaryElementOfKind:kind atIndexPath:indexPath];
CGRect frame = attributes.frame;
UILabel *label = [[UILabel alloc] initWithFrame: // CGRectMake based on header frame
label.tag = 1;
[header addSubview:label];
// configure label
return header;
}
I have got a Perfect solution:
let footerView = self.collectionView.visibleSupplementaryViews(ofKind: UICollectionView.elementKindSectionFooter)
Now you can access all subview of footerView by using:
footerView[0].subviews[0]
If you have label in your footerView then :
let label: UILabel = footerView[0].subviews[0] as? UILabel ?? UILabel()
Final Step:
label.text = "Successfully Updated Footer."
if let footerView = collectionView.subviews.first(where: {$0 is LoadingFooterCell}) as? LoadingFooterCell {
footerView.isLoading = .loading
}

Extjs 4.0.7 How do I re render my treepanel to see changes

I am creating an item selector with two boxes that move things back and forth within an extjs application. On the right box, I am creating buttons that serve to move items up and down. Essentially I am swapping the item with one above or below it. So, my code is straight forward in that regard
MoveUp: function(button, event, eOpts){
var theChosen = Ext.getStore('storeId').getRootNode().findChild('text', 'Chosen folder');
var chosenPanel = Ext.ComponenetQuery.query('#chosenTreePanel')[0];
var selected = chosenPanel.getSelectionModel().getSelection();
for( var i = 1; i < theChosen.childNodes.length; i++){
if(Ext.Array.contains(selected, theChosen.childNodes[i]) && (!Ext.Array.contains(selected, theChosen.childNodes[i-1]){
var temp = theChosen.childNodes[i];
theChosen.childNodes[i] = theChosen.childNodes[i-1];
theChosen.childNodes[i-1] = temp;
}
}
}
All of this code seems to work fine, because after clicking my button, and checking the DOM in firebug, I can see that the selected nodes have moved in the array correctly, however, this effect is never shown within my treepanel. ???How do I make the treepanel update when it's elements change. ???
TreePanel heirarchy looks like this just to clarify
Root Node
'Chosen Folder Node'
Array of items I am moving up and down within the 'folder'
I am USING VERSION 4.0.7
Attempting to use replaceChild() to fire an event to rerender does not behave as I expected
Changing:
var temp = theChosen.childNodes[i];
theChosen.childNodes[i] = theChosen.childNodes[i-1];
theChosen.childNodes[i-1] = temp;
To:
var temp = theChosen.childNodes[i];
theChosen.replaceChild(theChosen.childNodes[i-1], theChosen.childNodes[i]);
theChosen.replaceChild(temp, theChosen.childNodes[i-1]);
Results in odd behavior in which some nodes go missing. Certaintly not what I was looking for. Where am I going wrong here?
Tried the following code using the datachanged and (undocumented)refresh event:
Ext.getStore('storeId').fireEvent('datachanged', Ext.getStore('chosen') );
Ext.getStore('storeId').fireEvent('datachanged', Ext.getStore('chosen') );
This does not reload anything...
SOLUTION:
Use the insertChild method of nodeInterface....
I have noticed something strange in how insertChild works in that I need to change my index more based on moving up or down will explain with code below.
To move Up:
theChosen.insertChild( (i-1), theChosen.childNodes[i]);
To move down:
theChosen.insertChild( (i+2), theChosen.childNodes[i]);
Although the -1 vs +2 they both effectively move the item by one in the appropriate direction.
If you want to update the view of the nodes, I recommend using yourTree.getView().refresh();
But you can avoid that by using parentNode.insertChild(index, childNode); where index is where you want the node to show up and parentNode is the parent to the nodes you are reordering. ChildNode can be a config for a new node or any other nodeinterface that already exists. If the node does already exist and you use the insertChild method to insert it, it will automatically remove that node from whereever else it is.
So as you provided in your question in response to my answer, your code will work with something like (this is probably how I'd do it, but this is untested):
MoveUp: function(button, event, eOpts){
var chosenPanel = Ext.ComponenetQuery.query('#chosenTreePanel')[0];
var selectedNodes = chosenPanel.getSelectionModel().getSelection();
for( var i = 0; i < selectedNodes.length; i++){
var currentNode = selectedNodes[i];
if(!currentNode.isFirst())
{
var parentNode = currentNode.parentNode;
var newIndex = parentNode.indexOf(currentNode) - 1;
parentNode.insertChild(newIndex, currentNode);
}
}
}
Edit:
Back to the the responsible event question...
You need to fire the
'datachanged'
'refresh'
Events on the store with the store as only param. That should cause a UI update. But please note that I just had a glimpse into the sourcecode and I am sure this can all be done much smarter. At least a DD solution for this exists already.
If I find some time I my look into this again, but I guess you should be fine with these events for the first.
You never see anything cause you just do it without the appropriate methods that then fire the responsible events that cause rerender. Take a look at
appendChild()
removeChild()
replaceChild()
There may also be more methods that can help on the Ext.data.NodeInterface. I recommend you to use these instead of doing it under hood without any responsible event fired.
In addition to my second comment (just a wild guess without knowing if that is exactly what you want):
MoveUp: function(button, event, eOpts){
var target = Ext.getStore('storeId').getRootNode().findChild('text', 'Chosen folder');
var selected = chosenPanel.getSelectionModel().getSelection();
target.appendChild(selected);
}

WPF - is there a way to remove specific child from Canvas.Children?

I am working on a charting control where I am plotting the "analysis range," which is just two vertical lines on the chart. A problem arises when I want to change the analysis range, because I don't know how to remove only the two analysis range lines, so I end up clearing the chart and plotting the actual data values and whatnot again. Is there a way to tag these UI elements (i.e. analysis range is a gridline UI element) so that I can remove them specifically? I suppose I could save the "index" of the UI element somewhere and delete these, but I am wondering if there is a cleaner way of doing this. Thanks a lot.
All UIElements have a UID which is a string. You could set the UID of the range lines to something predictable. Keep in Mind that UID must be unique. Then when you need to remove only the gridlines, you iterate through the Children collection gathering a list of the UI elements that need to be removed, then remove them.
Something like this:
Canvas c = new Canvas();
c.Children.Add( new UIElement() { Uid = "Line1" } );
c.Children.Add( new UIElement() { Uid = "Line2" } );
c.Children.Add( new UIElement() { Uid = "Line3" } );
c.Children.Add( new UIElement() { Uid = "Text1" } ); //This is added as a sample
List<UIElement> itemstoremove = new List<UIElement>();
foreach (UIElement ui in c.Children)
{
if (ui.Uid.StartsWith("Line"))
{
itemstoremove.Add(ui);
}
}
foreach (UIElement ui in itemstoremove)
{
c.Children.Remove(ui);
}
That should work. A quick test of this code in debug shows the Children count at 1, with only the UIElement with Uid of Text1 present in the list.
When you add the two lines to the Canvas, can't you hold a reference to the two lines. That way, when you need to redraw them, just do a Canvas.Children.Remove(line1) and Canvas.Children.Remove(line2). Then update your references for the lines and re-add them to the Canvas. You could even just update the X and Y values of the lines themselves rather than removing and re-adding them. This way, the Chart would just move the lines.
But, basically the key is to maintain a reference to the lines after adding them to the Canvas.

three20 - can the query added to an openURLAction also be passed back to the parent

I am setting up routing to a TTTableViewController as follows:
[map from:#"myurl://filter/(initWithName:)"
toViewController:[FilterViewController class]];
and then, in another view controller I set up a mutable dictionary to pass through as my query:
// Set up dictionary and populate a field
NSMutableDictionary *filterDictionary;
filterDictionary = [[NSMutableDictionary alloc] init];
[filterDictionary setObject:#"test entry" forKey:#"test key"];
// Attach a query to the URL and open it
TTURLAction *theAction = [[TTURLAction actionWithURLPath:#"myurl://filter/search"]
applyQuery:filterDictionary];
[[TTNavigator navigator] openURLAction:theAction];
Finally, in the filter view controller, I can correctly access the values:
in .h:
#property (nonatomic, retain) NSMutableDictionary *filterDictionary;
in .m:
- (id)initWithName:(NSString *)filterName query:(NSMutableDictionary *)filters {
if (self = [self init]) {
self.filterDictionary = filters;
NSLog(#"Filter Dictionary assigned : %#", self.filterDictionary);
}
return self;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
if (filterDictionary)
[filterDictionary setObject:textField.text forKey:#"searchAddress"];
[textField resignFirstResponder];
return YES;
}
The dictionary is correctly mutable and I can add values etc. without problem. However, when my filterViewController is dismissed, I assumed the changed dictionary would be reflected in the parent - it was passed by reference correctly.
Am I missing something? Is my dictionary in the filterVC actually a copy due to a base class of Three20 somewhere?
I'm running into a similar issue. I suspect we may need to pass in a delegate (via that query), along with your dictionary as a separate object. Then have the parent honor a protocol defined in this new VC, wherein you can now pass back that dictionary at the proper time.
TTNavigator also has viewControllerForURL:query: (among others) for obtaining a VC without opening it, but perhaps passing in the query and having the VC "do the right thing" is enough, plus I think - accent on think - the idea is to start using URL Actions and not just URLs (in the Three20 sense).

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