Swift 3 JSON to array of objects is very slow - arrays

Question

I am upgrading my app from swift 2 to swift 3 and have a significant performance loss when building an array of custom objects. In swift 2 this took a few seconds while in swift 3 it takes around 30 seconds. I am using alamofire to return swiftyJSON, returning about 3000 rows of data. the alamofire return is quick, its looping through this json to build array of custom objects thats slow. These objects greatly simplify the code written when building table cells and passing data to new views.
Code:
class Customer {
var ID: String!
var sysName: String!
var address: String!
var contactID: String!
required init(_name:String?, _id: String?, _address:String?, _contactID:String?) {
//print(json)
if _id != nil {
self.ID = _id
}else{
self.ID = ""
}
if _name != nil {
self.sysName = _name
}else{
self.sysName = ""
}
if _address != nil {
self.address = _address
}else{
self.address = "No Address on File"
}
if _contactID != nil {
self.contactID = _contactID
}else{
self.contactID = ""
}
}
}
Alamofire.request(API.Router.customerList()).responseJSON() {
response in
print(response.request ?? "") // original URL request
print(response.response ?? "") // URL response
print(response.data ?? "") // server data
print(response.result) // result of response serialization
if let json = response.result.value {
print("JSON: \(json)")
self.customers = JSON(json)
self.parseJSON()
}
}
func parseJSON(){
let jsonCount = self.customers["customers"].count
self.totalCustomers = jsonCount
for i in 0 ..< jsonCount {
self.loadedCustomers = i
print("customer = \(self.customers["customers"][i] ["sysName"].string!)")
//VERY SLOW
//create a customer object
let customer = Customer( _name: self.customers["customers"][i]["sysName"].string!, _id: self.customers["customers"][i]["ID"].string!, _address: self.customers["customers"][i]["mainAddr"].string!, _contactID: self.customers["customers"][i]["contactID"].string!)
//add customer to customer array
self.customersArray.append(customer)
}
self.layoutViews() //build view, call all table methods
}
Thanks
Improved code:
import Foundation
import UIKit
import Alamofire
import SwiftyJSON
enum SearchMode{
case name
case address
}
class CustomerListViewController: ViewControllerWithMenu, UITableViewDelegate, UITableViewDataSource, UISearchControllerDelegate, UISearchBarDelegate, UISearchDisplayDelegate, UISearchResultsUpdating{
var indicator: SDevIndicator!
var totalCustomers:Int!
//data arrays
var ids = [String]()
var names = [String]()
var addresses = [String]()
var searchController:UISearchController!
var currentSearchMode = SearchMode.name
var customerTableView:TableView = TableView()
var layoutVars:LayoutVars = LayoutVars()
var sections : [(index: Int, length :Int, title: String)] = Array()
var customersSearchResults:[String] = []
var shouldShowSearchResults:Bool = false
let viewsConstraint_V:NSArray = []
let viewsConstraint_V2:NSArray = []
override func viewDidLoad() {
super.viewDidLoad()
title = "Customer List"
view.backgroundColor = layoutVars.backgroundColor
getCustomerList()
}
func getCustomerList() {
//remove any added views (needed for table refresh
for view in self.view.subviews{
view.removeFromSuperview()
}
// Show Indicator
indicator = SDevIndicator.generate(self.view)!
Alamofire.request(API.Router.customerList()).responseJSON() {
response in
//print(response.request ?? "") // original URL request
//print(response.response ?? "") // URL response
//print(response.data ?? "") // server data
//print(response.result) // result of response serialization
do {
if let data = response.data,
let json = try JSONSerialization.jsonObject(with: data) as? [String: Any],
let customers = json["customers"] as? [[String: Any]] {
for customer in customers {
if let id = customer["ID"] as? String {
self.ids.append(id)
}
if let name = customer["sysName"] as? String {
self.names.append(name)
}
if let address = customer["mainAddr"] as? String {
self.addresses.append(address)
}
}
}
} catch {
print("Error deserializing JSON: \(error)")
}
// build sections based on first letter(json is already sorted alphabetically)
var index = 0;
var firstCharacterArray:[String] = [" "]
for i in 0 ..< self.names.count {
let stringToTest = self.names[i].uppercased()
let firstCharacter = String(stringToTest[stringToTest.startIndex])
if(i == 0){
firstCharacterArray.append(firstCharacter)
}
if !firstCharacterArray.contains(firstCharacter) {
let title = firstCharacterArray[firstCharacterArray.count - 1]
firstCharacterArray.append(firstCharacter)
let newSection = (index: index, length: i - index, title: title)
self.sections.append(newSection)
index = i;
}
if(i == self.names.count - 1){
let title = firstCharacterArray[firstCharacterArray.count - 1]
let newSection = (index: index, length: i - index, title: title)
self.sections.append(newSection)
}
}
self.layoutViews()
}
}
func layoutViews(){
indicator.dismissIndicator()
searchController = UISearchController(searchResultsController: nil)
searchController.searchBar.placeholder = "Search Customers"
searchController.searchResultsUpdater = self
searchController.delegate = self
searchController.searchBar.delegate = self
searchController.dimsBackgroundDuringPresentation = false
searchController.hidesNavigationBarDuringPresentation = false
navigationItem.titleView = searchController.searchBar
let items = ["Name","Address"]
let customSC = SegmentedControl(items: items)
customSC.selectedSegmentIndex = 0
customSC.addTarget(self, action: #selector(self.changeSearchOptions(sender:)), for: .valueChanged)
self.view.addSubview(customSC)
self.customerTableView.delegate = self
self.customerTableView.dataSource = self
self.customerTableView.register(CustomerTableViewCell.self, forCellReuseIdentifier: "cell")
self.view.addSubview(self.customerTableView)
//auto layout group
let viewsDictionary = [
"view2":customSC,
"view3":self.customerTableView
]as [String:AnyObject]
let sizeVals = ["fullWidth": layoutVars.fullWidth,"width": layoutVars.fullWidth - 30,"navBottom":layoutVars.navAndStatusBarHeight,"height": self.view.frame.size.height - 100] as [String:Any]
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[view2(fullWidth)]", options: [], metrics: sizeVals, views: viewsDictionary))
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[view3(fullWidth)]", options: [], metrics: sizeVals, views: viewsDictionary))
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-navBottom-[view2(40)][view3(height)]", options: [], metrics: sizeVals, views: viewsDictionary))
}
/////////////// Search Methods ///////////////////////
func changeSearchOptions(sender: UISegmentedControl) {
switch sender.selectedSegmentIndex {
case 0:
currentSearchMode = .name
break
case 1:
currentSearchMode = .address
break
default:
currentSearchMode = .name
break
}
filterSearchResults()
}
func updateSearchResults(for searchController: UISearchController) {
filterSearchResults()
}
func filterSearchResults(){
customersSearchResults = []
switch currentSearchMode {
case .name:
self.customersSearchResults = self.names.filter({( aCustomer: String ) -> Bool in
return (aCustomer.lowercased().range(of: self.searchController.searchBar.text!.lowercased()) != nil) })
break
case .address:
self.customersSearchResults = self.addresses.filter({( aCustomer: String) -> Bool in
return (aCustomer.lowercased().range(of: self.searchController.searchBar.text!.lowercased()) != nil)
})
break
}
self.customerTableView.reloadData()
}
func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
//print("searchBarTextDidBeginEditing")
shouldShowSearchResults = true
self.customerTableView.reloadData()
}
func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
shouldShowSearchResults = false
self.customerTableView.reloadData()
}
func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
if !shouldShowSearchResults {
shouldShowSearchResults = true
self.customerTableView.reloadData()
}
searchController.searchBar.resignFirstResponder()
}
/////////////// TableView Delegate Methods ///////////////////////
func numberOfSections(in tableView: UITableView) -> Int {
if shouldShowSearchResults{
return 1
}else{
return sections.count
}
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
//print("titleForHeaderInSection")
if shouldShowSearchResults{
return nil
}else{
if(sections[section].title == "#"){
return " # \(self.totalCustomers) Customers Found"
}else{
return " " + sections[section].title //hack way of indenting section text
}
}
}
func sectionIndexTitles(for tableView: UITableView) -> [String]?{
print("sectionIndexTitlesForTableView 1")
if shouldShowSearchResults{
return nil
}else{
//print("sectionIndexTitlesForTableView \(sections.map { $0.title })")
return sections.map { $0.title }
}
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
//print("heightForHeaderInSection")
if shouldShowSearchResults{
return 0
}else{
return 50
}
}
func tableView(_ tableView: UITableView, sectionForSectionIndexTitle title: String, at index: Int) -> Int {
return index
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
//print("numberOfRowsInSection")
if shouldShowSearchResults{
return self.customersSearchResults.count
} else {
return sections[section].length
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = customerTableView.dequeueReusableCell(withIdentifier: "cell") as! CustomerTableViewCell
customerTableView.rowHeight = 50.0
if shouldShowSearchResults{
let searchString = self.searchController.searchBar.text!.lowercased()
if(currentSearchMode == .name){
cell.nameLbl.text = self.customersSearchResults[indexPath.row]
cell.name = self.customersSearchResults[indexPath.row]
if let i = self.names.index(of: cell.nameLbl.text!) {
//print("\(cell.nameLbl.text!) is at index \(i)")
cell.addressLbl.text = self.addresses[i]
cell.address = self.addresses[i]
cell.id = self.ids[i]
} else {
cell.addressLbl.text = ""
cell.address = ""
cell.id = ""
}
//text highlighting
let baseString:NSString = cell.name as NSString
let highlightedText = NSMutableAttributedString(string: cell.name)
var error: NSError?
let regex: NSRegularExpression?
do {
regex = try NSRegularExpression(pattern: searchString, options: .caseInsensitive)
} catch let error1 as NSError {
error = error1
regex = nil
}
if let regexError = error {
print("Oh no! \(regexError)")
} else {
for match in (regex?.matches(in: baseString as String, options: NSRegularExpression.MatchingOptions(), range: NSRange(location: 0, length: baseString.length)))! as [NSTextCheckingResult] {
highlightedText.addAttribute(NSBackgroundColorAttributeName, value: UIColor.yellow, range: match.range)
}
}
cell.nameLbl.attributedText = highlightedText
}else{//address search mode
cell.addressLbl.text = self.customersSearchResults[indexPath.row]
cell.address = self.customersSearchResults[indexPath.row]
if let i = self.addresses.index(of: cell.addressLbl.text!) {
cell.nameLbl.text = self.names[i]
cell.name = self.names[i]
cell.id = self.ids[i]
} else {
cell.nameLbl.text = ""
cell.name = ""
cell.id = ""
}
//text highlighting
let baseString:NSString = cell.address as NSString
let highlightedText = NSMutableAttributedString(string: cell.address)
var error: NSError?
let regex: NSRegularExpression?
do {
regex = try NSRegularExpression(pattern: searchString, options: .caseInsensitive)
} catch let error1 as NSError {
error = error1
regex = nil
}
if let regexError = error {
print("Oh no! \(regexError)")
} else {
for match in (regex?.matches(in: baseString as String, options: NSRegularExpression.MatchingOptions(), range: NSRange(location: 0, length: baseString.length)))! as [NSTextCheckingResult] {
highlightedText.addAttribute(NSBackgroundColorAttributeName, value: UIColor.yellow, range: match.range)
}
}
cell.addressLbl.attributedText = highlightedText
}
} else {
//print("make cell")
cell.id = self.ids[sections[indexPath.section].index + indexPath.row]
cell.name = self.names[sections[indexPath.section].index + indexPath.row]
cell.address = self.addresses[sections[indexPath.section].index + indexPath.row]
cell.nameLbl.text = self.names[sections[indexPath.section].index + indexPath.row]
cell.addressLbl.text = self.addresses[sections[indexPath.section].index + indexPath.row]
}
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let indexPath = tableView.indexPathForSelectedRow;
let currentCell = tableView.cellForRow(at: indexPath!) as! CustomerTableViewCell
let customerViewController = CustomerViewController(_customerID: currentCell.id)
navigationController?.pushViewController(customerViewController, animated: false )
tableView.deselectRow(at: indexPath!, animated: true)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}