Parse: Retrieving Data by Row - swift

Question

Overview: How can I make it so that when the cell with the segue
identifier of 0 will load data in the row that has 0 as its ID, cell with segue identifier of 1 will load data in the row that has 1 as its ID, and so on and so forth. The data includes ID (responds to cell identifier), navTitle (title of the navigation bar), written (who the article was written by), date (date of the article), and article (the article itself).
I am trying to make it so that once a cell is tapped in my tableview it opens data unique to that cell. What would the best way to do that? I was thinking that maybe I should have it check the ID column I have on Parse and load data the data in that row, but I'm not sure how to do that. Is there a better way to do this? Any help is appreciated! Feel free to ask me for any additional information.
^ So here I have a tableview in which data is being taken from Parse and used for both labels.
^ This view controller is segued to the cell above with:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if indexPath.row == 0 {
self.performSegueWithIdentifier("0a", sender: nil)
self.tableview.deselectRowAtIndexPath(indexPath, animated: true)
}
}
Here is my EventsDetailViewController, the one that is called when a cell is tapped:
import UIKit
import Parse
import ParseUI
import Bolts
class EventDetailViewController: UIViewController {
#IBAction func eventDetail(sender: AnyObject) {
dismissViewControllerAnimated(true, completion: nil)
}
#IBOutlet weak var articleTitle: UILabel!
#IBOutlet weak var writtenBy: UILabel!
#IBOutlet weak var date: UILabel!
#IBOutlet weak var article: UITextView!
#IBOutlet weak var navBar: UINavigationBar!
var dateDetail = [String]()
var articleDetail = [String]()
override func viewDidLoad() {
super.viewDidLoad()
loadEvents()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func loadEvents () -> Void {
var query = PFQuery(className: "eventsdetail")
query.findObjectsInBackgroundWithBlock {
(objects: [PFObject]?, error : NSError?) -> Void in
if error == nil {
if let objects = objects as [PFObject]! {
for object in objects {
var output1 = object.objectForKey("navTitle") as! String
self.navBar.topItem?.title = output1
var output2 = object.objectForKey("articleTitle") as! String
self.articleTitle.text = output2
var output3 = object.objectForKey("written") as! String
self.writtenBy.text = output3
var output4 = object.objectForKey("date") as! String
self.date.text = output4
var output5 = object.objectForKey("article") as! String
self.article.text = output5
}
}
}
}
}
}
Here is my EventsViewController:
import UIKit
import Parse
import Bolts
import ParseUI
class EventsViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var timer: NSTimer!
var isAnimating = false
var currentColorIndex = 0
var currentLabelIndex = 0
var customView: UIView!
var labelsArray: Array<UILabel> = []
var refreshControl: UIRefreshControl!
var testArray = [String]()
var subArray = [String]()
#IBOutlet weak var tableview: UITableView!
#IBOutlet weak var webView: UIWebView!
override func viewDidLoad() {
super.viewDidLoad()
refreshControl = UIRefreshControl()
tableview.delegate = self
tableview.dataSource = self
refreshControl.addTarget(self, action: Selector("loadEvents"), forControlEvents: UIControlEvents.ValueChanged)
self.tableview.addSubview(refreshControl)
loadEvents()
loadCustomRefreshContents()
//refreshControl colors
refreshControl.backgroundColor = UIColor.clearColor() //color of background
refreshControl.tintColor = UIColor.clearColor() //color of indicator
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func loadEvents () -> Void {
testArray = [String]()
subArray = [String]()
let query = PFQuery(className: "events")
let runkey = query.orderByDescending("eventTitle")
runkey.findObjectsInBackgroundWithBlock {
(objects: [PFObject]?, error:NSError?) -> Void in
if error == nil {
if let objects = objects as [PFObject]! {
for object in objects {
let load = object.objectForKey("eventTitle") as! String
self.testArray.append(load)
let subload = object.objectForKey("date") as! String
self.subArray.append(subload)
//reload TableView
self.tableview.reloadData()
print(self.testArray)
}
}
} else {
print("error:\(error!) \(error!.userInfo)")
}
}
refreshControl.endRefreshing()
}
func do_table_refresh() {
dispatch_async(dispatch_get_main_queue()) {
self.tableview.reloadData()
return
}
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if indexPath.row == 0 {
self.performSegueWithIdentifier("0a", sender: nil)
self.tableview.deselectRowAtIndexPath(indexPath, animated: true)
}
}
func tableView(tableView:UITableView!, numberOfRowsInSection section:Int) -> Int {
return testArray.count
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("eventcell", forIndexPath: indexPath) as! EventTableViewCell
cell.title.text = self.testArray[indexPath.row]
cell.subTitle.text = self.subArray[indexPath.row]
return cell
}
//refreshes tableview; starts refresh
func loadCustomRefreshContents() {
let refreshContents = NSBundle.mainBundle().loadNibNamed("RefreshControl", owner: self, options: nil)
customView = refreshContents[0] as! UIView
customView.frame = refreshControl.bounds
for var i=0; i<customView.subviews.count; ++i {
labelsArray.append(customView.viewWithTag(i + 1) as! UILabel)
}
refreshControl.addSubview(customView)
}
//stops refresh
func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
do_table_refresh()
if refreshControl.refreshing {
if !isAnimating {
animateRefreshStep1()
}
}
}
//cycles through colors
func getNextColor() -> UIColor {
var colorsArray: Array<UIColor> = [UIColor.magentaColor(), UIColor.brownColor(), UIColor.yellowColor(), UIColor.redColor(), UIColor.greenColor(), UIColor.blueColor(), UIColor.orangeColor()]
if currentColorIndex == colorsArray.count {
currentColorIndex = 0
}
let returnColor = colorsArray[currentColorIndex]
++currentColorIndex
return returnColor
}
func doSomething() {
timer = NSTimer.scheduledTimerWithTimeInterval(4.0, target: self, selector: "endOfWork", userInfo: nil, repeats: true)
self.do_table_refresh()
}
func endOfWork() {
refreshControl.endRefreshing()
timer.invalidate()
timer = nil
}
//first part of animation
func animateRefreshStep1() {
isAnimating = true
UIView.animateWithDuration(0.1, delay: 0.0, options: UIViewAnimationOptions.CurveLinear, animations: { () -> Void in
self.labelsArray[self.currentLabelIndex].transform = CGAffineTransformMakeRotation(CGFloat(M_PI_4))
self.labelsArray[self.currentLabelIndex].textColor = self.getNextColor()
}, completion: { (finished) -> Void in
UIView.animateWithDuration(0.05, delay: 0.0, options: UIViewAnimationOptions.CurveLinear, animations: { () -> Void in
self.labelsArray[self.currentLabelIndex].transform = CGAffineTransformIdentity
self.labelsArray[self.currentLabelIndex].textColor = UIColor.blackColor()
}, completion: { (finished) -> Void in
++self.currentLabelIndex
if self.currentLabelIndex < self.labelsArray.count {
self.animateRefreshStep1()
}
else {
self.animateRefreshStep2()
}
})
})
}
//second part of animation
func animateRefreshStep2() {
UIView.animateWithDuration(0.35, delay: 0.0, options: UIViewAnimationOptions.CurveLinear, animations: { () -> Void in
self.labelsArray[0].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[1].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[2].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[3].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[4].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[5].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[6].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[7].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[8].transform = CGAffineTransformMakeScale(1.5, 1.5)
self.labelsArray[9].transform = CGAffineTransformMakeScale(1.5, 1.5)
}, completion: { (finished) -> Void in
UIView.animateWithDuration(0.25, delay: 0.0, options: UIViewAnimationOptions.CurveLinear, animations: { () -> Void in
self.labelsArray[0].transform = CGAffineTransformIdentity
self.labelsArray[1].transform = CGAffineTransformIdentity
self.labelsArray[2].transform = CGAffineTransformIdentity
self.labelsArray[3].transform = CGAffineTransformIdentity
self.labelsArray[4].transform = CGAffineTransformIdentity
self.labelsArray[5].transform = CGAffineTransformIdentity
self.labelsArray[6].transform = CGAffineTransformIdentity
self.labelsArray[7].transform = CGAffineTransformIdentity
self.labelsArray[8].transform = CGAffineTransformIdentity
self.labelsArray[9].transform = CGAffineTransformIdentity
}, completion: { (finished) -> Void in
if self.refreshControl.refreshing {
self.currentLabelIndex = 0
self.animateRefreshStep1()
}
else {
self.isAnimating = false
self.currentLabelIndex = 0
for var i=0; i<self.labelsArray.count; ++i {
self.labelsArray[i].textColor = UIColor.blackColor()
self.labelsArray[i].transform = CGAffineTransformIdentity
}
}
})
})
}
}

Answer 1

Since you have the data on the tableView just make sure you create a segue in your storyboard connecting the prototype cell and the destination view controller and add an identifier to the segue.
Next, on the controller with the tableView make sure you call:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if (segue.identifier == "segueIdentifier"){
let detailScene = segue.destinationViewController as! EventDetailViewController
if let indexPath = self.tableView.indexPathForSelectedRow {
let row = Int(indexPath.row)
//here you can pass all the data to the destination viewController. But you CANT POPULATE YOUR LABELS. make sure you pass the data to some auxiliar variable(s). Next line is an example
detailScene.selectedData = (self.myData[row] as! PFObject)
}
}
}
Update:
detailScene.selectedData = (self.myData[row] as! PFObject)
detailScene is an instance of the destination viewController. selectedData is, in this case an instance of PFObject that will be use to populate the labels in my destination viewController. self.myData is an array in my source viewController with the data that is shown in my tableView.
So if you want to send the data you show in your cells. (
self.testArray[indexPath.row]
self.subArray[indexPath.row]
) make sure you declare the variables that will receive this data on your EventsDetailViewController something like this:
var testString:String!
var subString:String!
Then in your prepareForSegue (EventsViewController) make sure to instantiate this variables with the proper data:
detailScene.test = self.testArray[row]
detailScene.sub = self.subArray[row]
Finally on EventsDetailViewController you can pass the data to the labels you want on viewDidLoad():
self.articleTitle.text = testString
Let me know in case of any concerns.

Answer 2

What you are asking is the archetypical basic app: show a list of items in a tableview and being able to tap on a row to see more details.
What seems unusual to me is how you have two different classes: events and eventdetails.
Compare it with a database of books. You would not have a Book class and a BookDetails class. You would only have a Book class that contains all details about a book. So when you want to show a list of books, you fetch all the Book objects. In the tableviewcontroller you display a subset of fields from the Book objects (like i.e. title and author). When the user then taps on a specific book, you open a viewcontroller and pass it the Book object for that row. This detail viewcontroller then just shows MORE info/fields from that same Book object.