Modal segue needs 2 clicks instead of one - ios

My UITableView needs 2 clicks to show the detail page of the selected cell : one for selection and another one for show the detail view. I would like one clic to directly show the detail view of the clicked cell.
I use a modal segue with this method inside my UITableViewManager.m :
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showDetail"]) {
NSIndexPath *indexPath = [playerList indexPathForSelectedRow];
TCPlayerStat *object = _objects[indexPath.row];
[[segue destinationViewController] setPlayerStat:object];
}
}
I can't work with a push segue because I don't have Navigation Controller (and don't really want to).
I've looked in the TableView Attribute Inspector but didnt find out anything relevant for this. I have Selection "Single Selection" selected and "Show Selection on Touch" checked.
I don't know if this is possible and if it is, where to look..
Thanks for your help.
EDIT 1: When I write the two methods like this, it still doesn't work (needs 2 clicks) and I have a new warning log:
"Warning: Attempt to present TCDetailViewController: 0xa27b900 on
TCRootViewController: 0xa24f050 while a presentation is in progress!"
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self performSegueWithIdentifier:#"showDetail" sender:self];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showDetail"]) {
NSIndexPath *indexPath = [playerList indexPathForSelectedRow];
TCPlayerStat *object = _objects[indexPath.row];
TCDetailViewController *detailViewController = [segue destinationViewController];
[detailViewController setPlayerStat:object];
}
}
EDIT 2: I don't know why, but sometimes it works perfectly and doesn't need a second click on the table view. Can't find out :/
Solution below

I fond out what the problem was!
I changed a parameter on the Storyboard that I shouldn't have. I wanted the selection cell not to display a background highlight color when I click on it, but it seems the Segue is based on it to work decently.
HOW TO FIX:
In the storyboard, select your Table View Cell in the Navigator and don't chose the "None" option in "Selection" (Attributes Inspector). "Blue", "Gray" or "Default" seems to work nice.

I already had the selection attribute set to "Default" and was still experiencing the two-click problem. That suggestion did, however, point to a related solution. In didSelectRowAtIndexPath, call:
self.tableView.deselectRowAtIndexPath(indexPath, animated: false)
(I'm using Swift, obviously.)

I think the more correct way to solve this problem is to perform any action on Main thread, in your case triggering the segue:
Objective-C
dispatch_async(dispatch_get_main_queue(), ^{
[self performSegueWithIdentifier:#"showDetail" sender:self];
});
Swift
DispatchQueue.main.async {
self.performSegue(withIdentifier: "showDetail", sender: self)
}
It's actually a bug, related to the main RunLoop and tableViewCell, while selectionStyles force RunLoop to be awake (as it has to process the animation), if you don't have selectionStyle, plus you don't do any startup animations inside your presented viewController, RunLoop will go asleep sometimes.
If you, for some reason, don't want to do the action (in your case it's triggering the segue) on main thread, or you don't have startup animation on presented ViewController, you can simply add empty main thread call at the end and it will also trigger RunLoop to be awake.
Objective-C
[self performSegueWithIdentifier:#"showDetail" sender:self];
dispatch_async(dispatch_get_main_queue(), ^{});
Swift
self.performSegue(withIdentifier: "showDetail", sender: self)
DispatchQueue.main.async {}

A solution that works for me (XCode 9.2) and seems easy, but still allows for None for the Selection is :
As #Tulleb says, in the storyboard use anything but None for the Table View Cell "Selection", but then set it to .none in the code.
For example, like this...
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tv.dequeueReusableCell(withIdentifier: "cell")
cell?.selectionStyle = .none // This is the important line

Use
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
instead of
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
Then you can write any code and it works on the first click.

FYI. until now, with Xcode 8.2.1 and Swift 3.x, the issue also exists for my customized UICollectionViewCell subclass (But I suppose subclass is not needed to reproduce this issue. I have no time to test this case.).
I summarize the issue as: tapping on the previously selected cell will consume the tap event to cause deselection, instead of expectedly triggering the selection segues.
So the solution is to, either not use the selection segues, say, but use programmatically triggering segues, or deselect the cell itself whenever a selection segue is triggered.

Related

Have to press detail disclosure button twice for data to be passed using prepareForSegue method

EDIT: I have fixed this problem. The code is corrected to show this fix.
I have an app that uses a UITableViewController that displays a list of all 50 states separated into sections alphabetically. I have added the detail disclosure button to the prototype cell in the storyboard and the table displays all the correct information.
When I press the button on a cell, it should segue to a new viewController and display the name of the state as the view title and then display a picture of the license plate in the view.
I am using the -(void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath method to control the button press and then I am using the -(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender to control the values being passed to the new viewController.
The problem I am having is that when I press the detail disclosure button nothing gets passed. NSLogging the values in the new viewController outputs (null), (null) and the view has no title or picture. However, when I press back and then press the same cell's detail disclosure button a second time, it works like it should. The title is correct and the picture displays properly.
The same is true when I choose another cell, the viewController displays the last information sent and I have to press back and then choose the cell again for it to update. When choosing a different cell for the first time, (null, (null) is what the NSlog is outputting. So I believe what is happening is that the first time a detail disclosure button is pressed, no values are passed, but the second time it is pressed, the values are being passed.
Here is the relevant code:
-(void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
//Don't even use this method now.
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
UITableViewCell *cell = (UITableViewCell*)sender; //Added this line
self.path = [self.tableview indexPathForCell:cell]; //Added this line
if ([segue.identifier isEqualToString:#"stateSegue"])
{
self.controller = segue.destinationViewController;
self.controller.stateName = [self.stateArray[indexPath.section][indexPath.row]stateName];
self.controller.licensePlateURL = [self.stateArray[indexPath.section][indexPath.row]licensePlateURL];
}
}
Any help with this would be greatly appreciated.
Check which method fires first. Maybe you set properties after segue is performed.
There's no informations about how (when) do you perform segue.
You could add this line to your accessoryButton method:
[self performSegueWithIdentifier:yourIdentifierFromStoryboard sender:self];

prepareForSegue called before didSelectRowAtIndexPath only when third segue is added

I have 3 segues to 3 different views. 2 are implemented with no problem, it is when the third is created that the problems occur.
I have the following didSelectRowAtIndexPath method:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
NSLog(#" ---------- did select row");
if(indexPath.section == 0){
if(indexPath.row == [self.data count]-1){
//prior to adding this, everything works
[self performSegueWithIdentifier:#"MoreComments" sender:self];
}else{
[self performSegueWithIdentifier:#"FriendView" sender:friend];
}
}else if(indexPath.section == 1){
if(indexPath.row == [self.data2 count]-1){
[self performSegueWithIdentifier:#"MorePosts" sender:self];
}else{
[self performSegueWithIdentifier:#"FriendView" sender:friend];
}
}
}
I have the following prepareForSeque method:
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if([segue.identifier isEqualToString:#"MorePosts"]){
MorePostsViewController *mfamvc = segue.destinationViewController;
mfamvc.data = self.data;
}else if([segue.identifier isEqualToString:#"FriendView"]){
FriendViewController *fvc = segue.destinationViewController;
fvc.friend = friend;
}else if([segue.identifier isEqualToString:#"MoreComments"]){
MoreCommentsViewController *mcvc = segue.destinationViewController;
mcvc.data = self.data2;
}
}
Before control dragging from my cell to the last view I can see that my program hits didselectrow and then prepareforseque. This makes all the view navigation work perfect.
As soon as I control drag from my cell to the MoreCommentsViewController I start to see the error:
nested push animation can result in corrupted navigation bar
Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
I notice that now also prepareforseque is being called twice, with prepareforseque being called first, then didselectrow, then prepareforsegue again.
What am I doing wrong to conditionally go to these different views?
You should use either didSelectRowAtIndexPath or segues from cell, but not both. If you want your didSelectRowAtIndexPath to invoke segues, those segues should not be from the cell to the next scene, but rather from the view controller icon in the bar above the scene:
You can now select this new segue, go to the "attributes inspector" (option+command+4), and supply a storyboard identifier which you can reference in your code when you call performSegueWithIdentifier.
The reason is you can't drag from a tableview cell to multiple views. As #rdelmar mentioned this is wrong. You should drag from the destination to the source view and then handle manually the way I did above.
Also can be found here: Conditional segue performed on tap on UITableViewCell

sending some data via prepareForSegue issue

I have some issue when doing the segue with some data to to another view.
I have a contact book, first tableview is displaying contacts correctly, also with images
While I click on contact it should perform segue to another tableView. But from some reason it takes only first contact (seems like it's not in a loop).
I have one class for contacts and second ViewController. I can't understand why it happens
I created "pastie" link:
Here is the link to My code, to save place
I checked your code and I think that the problem is when the prepareForSegue is called the selected row is already deselected from didSelectRowAtIndexPath. I think that the best approach here is to send the selected index path from didSelectRowAtIndexPath into performSegue method something like:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[self.contTableView deselectRowAtIndexPath:indexPath animated:YES];
[self performSegueWithIdentifier:#"NextTable" sender:indexPath];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"NextTable"]) {
NSIndexPath *indexPath = (NSIndexPath*)sender
contact = self.contactsToShow[indexPath.row];
[segue.destinationViewController setPhoneNumbers:contact.numbers];
}
}
In order for this approach to work you must link the segue between view controllers not between cell and table view controller.
The Problem is line 196: You wanna have the index path for the selected row. But because in line 215 you are deselecting the cell immediately after being selected, the index path is always 0.

Storyboards and programmatically views

I'm totally lost in this issue. I have been working with storyboards, I have created a navigation controller with tableviews and some stuff. There are Services in each row of the tableview and I need to create one detail view for each service.
There are a lot of services, so I can't create them in the storyboard. The idea is to download the Services from a webservice (number of parameters, types of each one, etc..) and add as textfields / buttons as appropriate to the Service.
So, my problems and questions are:
1) Can I combine Storyboards and views programmatically? When I create a NewView in MyTableviewClass, should I do it in my prepareforsegue method? How can I show it in the screen without loosing my navigation controller? this is what I have (it doesn't work: it says to me that there is no segue with name 'Service1' ) :
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
if ([[segue identifier] isEqualToString:#"NextLevel"]) {
[segue.destinationViewController setActualNodo:[actualNodo getSonAtIndex:indexPath.row]];
} else if ([[segue identifier] isEqualToString:#"Service1"]) {
CGRect bounds = self.view.bounds;
UIView *myview = [[UIView alloc] initWithFrame:bounds];
[myview setBackgroundColor: [UIColor redColor]];
[self.view addSubview:myview];
[self.view bringSubviewToFront:myview]; }
Any book or reference is welcomed but I couldn't find anything similar. Is this very complicated in iOS? I have done a similar thing in Java. I have read about generating interfaces dynamically with XIBs but, sincerely, I don't know what it is..
Thanks for all.
Yes you can create a StoryBoard with a view and then add views programmatically to it.
You should not try creating a view within your prepareForSegue method. This really should be used for passing objects to another ViewController.
I would suggest this to you. Go back to your StoryBoard and create a new UIViewController scene. Click on your first scene and CTRL drag to the new scene. Next, click on your segue and give it a name.
Step 1:
Create a new class called ServicesViewController and make sure it's a subclass of `UIViewController:
Step 2:
Go back to your StoryBoard and click on scene so that it is selected. Next, click on the Files Owner and finally click on the class info button (the third button) and finally select your ServiceViewController class you just created.
Step 3:
Back in your ServicesViewController in the didSelectRowAtIndex method call your seque:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self performSegueWithIdentifier:#"YOUR_SEGUE_NAME" sender:nil];
}
For now, clean out all the code in your prepareForSegue method and just get the transition down first.
In addition to Flea's answer, if you need to keep the navigation controller, just create a push segue in your storyboard by control dragging from the file owner icon (the yellow box under your view controller's view) of the table view controller to the ServiceViewController you added to the storyboard, this should show a popup window where you can select "push" as the type of the segue. Next, select the segue and in the attribute inspector (the fourth button, next to the one in the snapshot) and in the "Identifier" text field type in a unique identifier for your segue, such as serviceSegue.
At this point, using Flea's code:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self performSegueWithIdentifier:#"serviceSegue" sender:nil];
}
And in the code you posted:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
if ([[segue identifier] isEqualToString:#"serviceSegue"])
[segue.destinationViewController setActualNodo:[actualNodo getSonAtIndex:indexPath.row]];
}
I'm not sure what you are trying to do with the other segue "Service1", but if you want to change the view of the TableViewController, segues are not the way to do it. If anything you should do it in the didSelectRowAtIndexPath method depending on the row selected:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (You want to transition to other view controller)
[self performSegueWithIdentifier:#"serviceSegue" sender:nil];
else
Change your view here.
}
I hope this helps!
It sounds like you just have multiple cells in a tableView. Instead of using segues you can simply create different cells with different identifiers and show or hide them based on what services are detected in your services array which is populated from your web service.

Conditional Segue navigation from UITableViewCell based on response to UIAlertView

My problem seems like a generic problem, yet can't seem to find an answer for it.
I have a situation where when the user taps on a custom UITableViewCell, I would like to display an alert and then based on the response to the alert, either stay on the same view (user selecting cancel) or display another view (if the user selects proceed). And I would like to do this using the storyboard feature & segues.
How would one go about this? Do you have to do this the old fashioned way?
#user, Just create the alertView the old fashion way; I do know of any storyboard feature to do this differently. Where storyboard can help is with the segues. You can call the segues programmatically. With you alert view cancel button you can just return (i.e. do nothing). For the other option, to display another view, you can programmatically call a segue to transition to the desired view. If you don't have the proper segue already defined for some other reason on your storyboard, just create a button out and use that to create the segue and name it. Name the segue by clicking on it in storyboard and use the attributes inspector to give it name (identifier). Then hide the button or put it out of the view. I typically put these type of button on the toolbar and use spacers to keep them out of the view. Here's some sample code:
Call the segue from the alert view delegate like this:
[self performSegueWithIdentifier: #"done" sender: self];
Also implement this method to do any necessary task to prepare for the segue:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"done"])
{
// [[segue destinationViewController] setManagedObjectContext:self.managedObjectContext];
// [[segue destinationViewController] setSelectedClient:selectedClient];
}
}
You can create segues directly from the startingViewController to multiple destinationViewControllers that can then be "performed" programmatically. You do not need to create any hidden buttons for them, which does seem like a hack.
OK I came up with a solution in keeping with the storyboard that I like.
Example:
My tableview has 2 sections, grouped, and cells are dynamic prototype. Section 0 contains one row/UITableViewCell & I don't want it to segue. Section 1 contains multiple cells that I want to trigger the segue & drill down into the detail.
In Storyboard:
I removed the segue linking the tableviewcell to the destination view controller.
I made a 'generic' segue linking the source view controller directly to the destination view controller.
In the attributes on the segue, I set the identifier ('EditTimePeriod') and set the type to Push (I presume Modal would work just the same).
In the source view controller:
In the prepareForSegue method I handled both the common 'AddTimePeriod' segue I control-dragged from my UIBarButtonItem (Add), along with the 'generic'(vc-->vc) 'EditTimePeriod' segue.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
// handle the click of the 'Add' bar button item
if([segue.identifier isEqualToString:#"AddTimePeriod"]) {
TimePeriodViewController* tpvc = (TimePeriodViewController*)segue.destinationViewController;
tpvc.delegate = self;
// database & entity stuff for adding the new one to the mOC, etc
}
// handle the click of one of the 'editable' cells -
if([segue.identifier isEqualToString:#"EditTimePeriod"]) {
TimePeriodViewController* tpvc = (TimePeriodViewController*)segue.destinationViewController;
tpvc.delegate = self;
TimePeriod * newTP = [self.timePeriodArray objectAtIndex:self.tableView.indexPathForSelectedRow.row];
tpvc.timePeriod = newTP;
}
}
Then I implemented the tableView:didSelectRowAtIndexPath method, and put my condition in here. If the selected row was outside of section zero I called the EditTimePeriod segue manually, defining the sender as the selected tableviewcell:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if(self.tableView.indexPathForSelectedRow.section!=0){
[self performSegueWithIdentifier:#"EditTimePeriod" sender:[tableView cellForRowAtIndexPath:indexPath]];
}
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
return;
}
would be nice to code the cell in section 0 so that it is not selectable in the first place!
Hope this helps though.
** and then 5 minutes later I took another look and realized I could just move the data from section 0 into the section header, which is more intuitive and wasn't being used anyway. leaving the design open for a standard segue from each tableviewcell without needing any condition/check. Was a good exercise anyway though :)

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