Understanding Search and Filtering in Swift 4 with UITableCell

Introduction

In this article, we will explore how to implement search functionality in a UITableViewController using Swift 4. This involves understanding how to filter data based on user input and update the table view accordingly.

We will start by examining the code provided in the question and then move on to an improved solution using Swift 4’s features for filtering data.

Understanding the Problem

The original code attempts to filter data based on the text entered into a UISearchBar. The problem arises when trying to compare a string with an integer value. This is due to the fact that BookedOrderId is declared as an Int, which cannot be directly compared with a string.

To solve this issue, we need to find alternative methods for filtering data that can handle both string and integer values.

Understanding Filter Method in Swift

The filter method is used to create a new array containing only the elements of the original array for which the predicate returns true.

let numbers = [1, 2, 3, 4, 5]
let evenNumbers = numbers.filter { $0 % 2 == 0 }

In this example, evenNumbers is a new array containing only the elements from numbers for which the condition $0 % 2 == 0 returns true.

Implementing Search Functionality

To implement search functionality in our table view controller, we need to create a copy of our original data and use it over the view controller. This allows us to filter the data based on user input without affecting the original array.

Here is an example of how you can do this:

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    // When there is no text, filteredData is the same as the original data
    // When user has entered text into the search box
    // Use the filter method to iterate over all items in the data array
    // For each item, return true if the item should be included and false if the
    // item should NOT be included

    self.searchBar.showsCancelButton = true

    var copied_order_Canceled_DetailList: [OrderBookedSetterGetter] = []
    for item in self.order_Canceled_DetailList {
        if String(item.orderId).localizedCaseInsensitiveContains(searchText) != false{
            copied_order_Canceled_DetailList.append(item)
        } else {
            // Do nothing
        }
    }

    self.copied_order_Canceled_DetailList = copied_order_Canceled_DetailList

    self.tableview.reloadData()
    if searchText == "" {
        self.copied_order_Canceled_DetailList = self.order_Canceled_DetailList
        self.tableview.reloadData()
    }
}

In this code, we create a copy of order_Canceled.DetailList and use it to filter the data based on user input. We then update copied_order_Canceled_DetailList with the filtered data.

UnderstandinglocalizedCaseInsensitiveContains Method

The localizedCaseInsensitiveContains method is used to check if a string contains another string in a case-insensitive manner.

let str1 = "Hello"
let str2 = "hello"

if str1.localizedCaseInsensitiveContains(str2) {
    print("str1 contains str2")
}

In this example, the code will print "str1 contains str2" because str1 and str2 are identical when ignoring case.

Conclusion

In this article, we explored how to implement search functionality in a UITableViewController using Swift 4. We examined the problem of comparing a string with an integer value and provided alternative solutions using filter method and localizedCaseInsensitiveContains method.

Last modified on 2023-11-17