How to filter objects by string comparison in Swift - swift

Question

I'm having an array of models:
struct Contact {
var givenName: String!
var familyName: String!
var organizationName: String!
}
I want to filter those contacts using ONE UITextField. My current problem is to define between words and filter only contacts matching all words.
For example:
var contacts: [Contact] = [Contact(givenName: "David", familyName: "Seek", organizationName: "Aldi"),
Contact(givenName: "Johne", familyName: "Doe", organizationName: "Kaisers"),
Contact(givenName: "Jane", familyName: "Doe", organizationName: "Tengelmann"),
Contact(givenName: "Marco", familyName: "Seidl", organizationName: "Rewe"),
Contact(givenName: "Filip", familyName: "Halbig", organizationName: "Aldi")]
I want to enter: David Aldi and only find David who works at Aldi. I don't want to see Filip who also works at Aldi.
Also if I enter David Do, I don't want to see any contacts, because none should match.
func getSearchResults(_ filterKey: String) {
self.presentActivityIndicator()
var processed: Int = 0
self.filteredContacts.removeAll()
DispatchQueue.global(qos: .background).async {
for contact in self.unfilteredContacts {
processed += 1
let lowercasedGivenName = contact.givenName.replacingOccurrences(of: " ", with: "").lowercased()
let lowercasedFamilyName = contact.familyName.replacingOccurrences(of: " ", with: "").lowercased()
let lowercasedOrganizationName = contact.organizationName.replacingOccurrences(of: " ", with: "").lowercased()
let name = lowercasedGivenName.appending(lowercasedFamilyName)
if name.range(of: filterKey.replacingOccurrences(of: " ", with: "")) != nil {
if !self.filteredContacts.contains(contact) {
self.filteredContacts.append(contact)
}
}
for word in filterKey.components(separatedBy: " ") {
if lowercasedOrganizationName.range(of: word.lowercased()) != nil {
if !self.filteredContacts.contains(contact) {
self.filteredContacts.append(contact)
}
}
}
if processed == self.unfilteredContacts.count {
self.reloadTableViewInMainThread()
}
}
}
}
This is one of the several approaches I've tried today. But with every try, I've been ending up, filtering out David and by entering the second name, I have found other contacts not matching the first name David, but match for example part of the family name or company name.
What am I missing and would be the best approach for this? Help is very appreciated.

Answer 1

First separate the filterKey into space separated components
let components = filterKey.components(separatedBy: " ")
then use the filter function with the closure syntax
self.filteredContacts = contacts.filter { contact -> Bool in
for string in components {
if contact.givenName != string && contact.familyName != string && contact.organizationName != string {
return false
}
}
return true
}
The closure returns true if the contact matches all components.
Wrapped in the function it's
func getSearchResults(_ filterKey: String) {
let components = filterKey.components(separatedBy: " ")
self.filteredContacts = contacts.filter { contact -> Bool in
for string in components {
if contact.givenName != string && contact.familyName != string && contact.organizationName != string {
return false
}
}
return true
}
}
Note:
Please, please never declare properties / members as implicit unwrapped optionals which are initialized with an init method. It perfectly legal (and recommended) to declare the members without the exclamation marks. However if they are supposed to be optional declare them as real optional (question mark).
And if the values won't change declare the members as constants (let).
struct Contact {
let givenName: String
let familyName: String
let organizationName: String
}
Edit:
To filter the contacts whose properties contain filterKey write
self.filteredContacts = contacts.filter { contact -> Bool in
for string in components {
if !contact.givenName.lowercased().contains(string) &&
!contact.familyName.lowercased().contains(string) &&
!contact.organizationName.lowercased().contains(string) {
return false
}
}
return true
}
To filter the contacts whose properties begin with filterKey write
self.filteredContacts = contacts.filter { contact -> Bool in
for string in components {
if !contact.givenName.lowercased().hasPrefix(string) &&
!contact.familyName.lowercased().hasPrefix(string) &&
!contact.organizationName.lowercased().hasPrefix(string) {
return false
}
}
return true
}

Answer 2

func getSearchResults(contacts: [Contact], filterKeys: String) -> [Contact] {
let keys = filterKeys.components(separatedBy: " ")
var contactsFiltered = contacts
keys.forEach { key in
contactsFiltered = contactsFiltered.filter {
$0.givenName == key || $0.familyName == key || $0.organizationName == key
}
}
return contactsFiltered
}
I splitted the filterKeys by blank spaces. Then, for each key, I check if the value exists in contact attribute.
If do you want a pure functional solution, you can use Set and intersection:
func getSearchResults(contacts: [Contact], filterKeys: String) -> [Contact] {
let keys = filterKeys.components(separatedBy: " ")
return contacts.filter {
Set([$0.givenName, $0.familyName, $0.organizationName]).intersection(keys).count >= keys.count
}
}
And, if do you want a crazy solution with Mirror, for when adding a new attribute in Contact, you do not need to update getSearchResults:
func getSearchResults(contacts: [Contact], filterKeys: String) -> [Contact] {
let keys = filterKeys.components(separatedBy: " ")
return contacts.filter {
let stringAttr = Mirror(reflecting: $0).children.filter { ($0.value as? String) != nil }
let contactValues = stringAttr.map { $0.value as! String }
return Set(contactValues).intersection(keys).count >= keys.count
}
}
Use with caution my last code (or never use it)
Edit
For match part of string in key.
func getSearchResults(contacts: [Contact], filterKeys: String) -> [Contact] {
let keys = filterKeys.components(separatedBy: " ").map { $0.lowercased() }
var contactsFiltered = contacts
keys.forEach { key in
contactsFiltered = contactsFiltered.filter {
$0.givenName.lowercased().range(of: key) != nil ||
$0.familyName.lowercased().range(of: key) != nil ||
$0.organizationName.lowercased().range(of: key) != nil
}
}
return contactsFiltered
}