RxSwift - trigger search programmatically in UISearchBar - ios

Question

I am observing UISearchBar.rx.text attributes to perform some search related Action when User types some text.
But at some time, I also would like to trigger this search Action programmatically. For instance at the creation of the view like in this example, where unfortunately the "Searching for [...]" text is not printed.
import UIKit
import RxSwift
import RxCocoa
class ViewController: UIViewController {
#IBOutlet weak var mySearchBar: UISearchBar!
let disposeBag = DisposeBag()
override func viewDidLoad() {
super.viewDidLoad()
// Trigger search when text changes
mySearchBar.rx.text.subscribe(onNext: { (text)
print("Searching for \(text)...")
// do some search Action
}
.disposed(by: disposeBag)
// Programmatically trigger a search
mySearchBar.text = "Some text to search"
}
}
The problem is changing mySearchBar.text does not trigger a new rx.text Event. Is there some way to do so?
For instance, I know thanks to this post that with an UITextField, this is possible using the UITextField.sendActions(for: .ValueChanged) function. Is there some similar way to do so with UISearchBar?

Answer 1

You could use a Variable<String?> as a sink for your search bar updates. That way you could also set its value programmatically, and use the variable instead of the search bar directly to drive your action:
class ViewController: UIViewController {
let searchText = Variable<String?>(nil)
let searchBar = UISearchBar()
let disposeBag = DisposeBag()
override func viewDidLoad() {
super.viewDidLoad()
searchBar.rx.text.asDriver()
.drive(searchText)
.disposed(by: disposeBag)
searchText.asObservable().subscribe(onNext: { [weak self] (text) in
if let welf = self, welf.searchBar.text != text {
welf.searchBar.text = text
}
})
.disposed(by: disposeBag)
searchText.value = "variables so cool"
searchText.asObservable().subscribe(onNext: { [weak self] (text) in
self?.doStuff(text)
})
.disposed(by: disposeBag)
}
}

Answer 2

This is a simple usage of Drivers
import UIKit
import RxCocoa
import RxSwift
class SearchViewController: UIViewController {
#IBOutlet weak var searchBar: UISearchBar!
let disposeBag = DisposeBag()
override func viewDidLoad() {
super.viewDidLoad()
let dataModels = Driver.just(["David", "Behrad","Tony","Carl","Davidov"])
let searchingTextDriver = searchBar.rx.text.orEmpty.asDriver()
let matchedCases = searchingTextDriver.withLatestFrom(dataModels){ searchingItem,models in
return models.filter({ (item) -> Bool in
return item.contains(searchingItem)
})
}
matchedCases.do(onNext: { (items) in
print(items)
}).drive().disposed(by: disposeBag)
}
}
As you see we created a dataModels Driver that it could be a response of your network or dataBase fetching.
the searching text converted to Driver then mixed with the dataModels to create matchedCases.

Answer 3

Yes same works for UITextBar.
Setting .text programmatically does not trigger the action automatically, I don't know why! but this is the case for UITextField too.
Call sendActions after each time you update .text property of a UIView subclass.
Try this :
// Programmatically trigger a search
mySearchBar.text = "Some text to search"
mySearchBar.sendActions(for: .valueChanged)