swift - 在tableView中加载搜索数据时如何停止Firestore分页
问题描述
我使用无限滚动在 tableView 中填充我的 Firestore 数据。我还有一个用于搜索的 searchBar。我成功地对数据进行了分页,但是当我搜索某些内容并使用已找到的数据重新加载 tableView 时,滚动后分页再次开始。无法禁用滚动,因为数据可能超过屏幕高度。
下面我提供我的代码。
var fetchMoreIngredients = false
var reachEnd = false
let leadingScreensForBatching: CGFloat = 10.0
//When user scrolls down it begins to fetch more.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let off = scrollView.contentOffset.y
let off1 = scrollView.contentSize.height
if off > off1 - scrollView.frame.height * leadingScreensForBatching{
if !fetchMoreIngredients && !reachEnd{
print(fetchMoreIngredients)
beginBatchFetch()
}
}
}
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
guard !searchText.isEmpty else {
ingredientsArray.removeAll()
beginBatchFetch()
return
}
}
func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
let text = searchBar.text!.lowercased()
searchIngredients(text: text)
self.searchBarIngredient.endEditing(true)
print("\(searchIngredients(text: text))")
}
func beginBatchFetch() {
let settings = FirestoreSettings()
settings.isPersistenceEnabled = false
fetchMoreIngredients = true
let db = Firestore.firestore()
db.settings = settings
var query: Query!
if ingredientsArray.isEmpty {
SVProgressHUD.show()
query = db.collection("Ingredients").limit(to: 4)
print("First 4 ingredient loaded")
} else {
query = db.collection("Ingredients").start(afterDocument: lastDocument).limit(to: 4)
print("Next 4 ingredient loaded")
}
query.getDocuments { (querySnapshot, err) in
if let err = err {
print("\(err.localizedDescription)")
print("Test Error")
} else if querySnapshot!.isEmpty {
self.fetchMoreIngredients = false
return
} else {
if (querySnapshot!.isEmpty == false){
let res = querySnapshot!.documents.compactMap({Ingredients(dictionary: $0.data())})
self.ingredientsArray.append(contentsOf: res)
self.tableView.reloadData()
self.fetchMoreIngredients = false
SVProgressHUD.dismiss()
}
self.lastDocument = querySnapshot!.documents.last
}
}
}
func searchIngredients(text: String){
fetchMoreIngredients = false
let db = Firestore.firestore()
db.collection("Ingredients").whereField("compName", arrayContains: text).getDocuments{ (querySnapshot, err) in
if let err = err {
print("\(err.localizedDescription)")
print("Test Error")
} else {
if (querySnapshot!.isEmpty == false){
self.searchedIngredientsArray = querySnapshot!.documents.compactMap({Ingredients(dictionary: $0.data())})
self.ingredientsArray = self.searchedIngredientsArray
self.tableView.reloadData()
}else{
print("No Ingredients were found")
}
}
}
}
提前致谢!
解决方案
解决方案
我终于找到了解决方案。在searchIngredients(text: String)
函数中,我应该fetchMoreIngredients
在开头和闭包中声明为 true。
func searchIngredients(text: String){
fetchMoreIngredients = true
let db = Firestore.firestore()
db.collection("Ingredients").whereField("compName", arrayContains: text).getDocuments{ (querySnapshot, err) in
if let err = err {
print("\(err.localizedDescription)")
print("Test Error")
} else {
if (querySnapshot!.isEmpty == false){
self.searchedIngredientsArray = querySnapshot!.documents.compactMap({Ingredients(dictionary: $0.data())})
self.ingredientsArray = self.searchedIngredientsArray
self.tableView.reloadData()
self.fetchMoreIngredients = true
}else{
print("No Ingredients were found")
}
}
}
}
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