Swift

Defining URLs using String literals in Swift

Almost every URL out there is constructed using a string, while the Foundation provides a very convenient way to construct a URL from a string using URL(string:) still we can add some sugar to make it even easier to use!

```swift
extension URL: ExpressibleByStringLiteral {
    public init(stringLiteral value: String) {
        guard value.representingValidURL, let url = URL(string: "\(value)") else {
            fatalError("\(value) cannot be mapped to a url")
        }
        self = url
    }
}

private extension String {
    var representingValidURL: Bool {
        let detector = try? NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
        if let match = detector?.firstMatch(in: self, options: [], range: NSRange(location: 0, length: self.utf16.count)) {
            return match.range.length == self.utf16.count
        } else {
            return false
        }
    }
}

// You can use it as follows 
let url: URL = "https://www.alihilal.com"
let task = URLSession.shared.dataTask(with: url)

```

Dynamic UITableView Header Resizing

Dealing with dynamic sizing of table view is a bit quirky this is an easy way to implement a variable height header.

```swift
extension UITableView {
    func resizeHeaderToFit() {
        guard let header = tableHeaderView else { return }
        let newSize = header.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize)
        if newSize.height != header.frame.height {
            header.frame.size.height = newSize.height
            tableHeaderView = header
        }
    }
}

// Usage
override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    tableView.resizeHeaderToFit()
}
```

Render a UIView instance as an Image

Converting a UIView to an image and save it is a common practice for many of us. Here is a convenient way to do that.

```swift
extension UIView {
    func snapshot() -> UIImage {
        let renderer = UIGraphicsImageRenderer(bounds: bounds)
        return renderer.image { action in
            layer.render(in: action.cgContext)
        }
    }
}

```

Comparing Reference types

Equitable doesn't fit as well with reference types as with value types. Here is a nice Equitable extension to deal with reference types.

```swift
extension Equatable where Self: AnyObject {
    static func ==(lhs: Self, rhs: Self) -> Bool {
        return lhs === rhs
    }
}

// Usage
class View: Equatable { }
let view = View()
let views = [View]()
assert(views.contains(view))
```

MongoDB

Useful Aliases to Run MongoDB on macOS

Before MongoDB v4.2.3, dealing with it was pretty easy from the terminal. We could run the mongod command to start MongoDB. This no longer works from MongoDB v4.2.3 onwards. Here is some useful shorthands.

```bash
alias mongod='brew services run mongodb-community'
alias mongod-status='brew services list'
alias mongod-stop='brew services stop mongodb-community'
```

Easily undo a local commit in Git

An easy to remember way for deleting or undoing the last commit from your local Git repository

```bash
# Make global configuration to set a delet-last-commit alias 
$   git  config  -- global  alias.delete-last-commit  "reset --soft HEAD ~1"

# Usage :)
$   git delete-last-commit
```

Pull another remote git branch without  switching branches

If you want to pull a git branch without switching branches you can use the following

```bash
git fetch origin master:master
```

Remove all leading and trailing white spaces of string in Swift

handy Swift string extension that helps to remove all leading and trailing white spces in a string

```swift
extension String {
     func strip() -> String { 
         return self.trimmingCharacters(in: .whitespaces)
     }
}

// White spaced string
var string = "    Hello, World   "
string.strip()

// Result -> "Hello, World"
```

Xcode

A tip for debugging using compiler directives in Xcode

Here is a tip to help you debug your swift code in a better way in Xcode

```swift
import  UIKit

class HomeVC:  UIViewController {
    func  sayHi() { 
        //.....
        //sth cause failure let us print who is that guy
        print("failure \(#function) "in line \(#line) ", file \(#file)) 
    }
}

let  mainVC = HomeVC()
mainVC.sayHi()
 
/*
    output: failure sayHi() in line 9, fileMyPlayground.playground
*/
```

Checking if the collection is not empty

A more convenient way to check collection emptiness in swift

```swift
extension Collection  { 
    var isNotEmpty: Bool{ !isEmpty }
}

// conventional way
if  !array.isEmpty { // do sth}

// more readable way
if  array.isNotEmpty { // do sth}
```

Code Tips and Tricks

Defining URLs using String literals in Swift Swift

Dynamic UITableView Header Resizing iOS

Render a UIView instance as an Image iOS

Comparing Reference types Swift

Useful Aliases to Run MongoDB on macOS MongoDB

Easily undo a local commit in Git Git

Pull another remote git branch without switching branches Git

Remove all leading and trailing white spaces of string in Swift Swift

A tip for debugging using compiler directives in Xcode Xcode

Checking if the collection is not empty Swift