Git global settings on MacOS

For MacOS Sierra, we can configure user name and user email as global settings for a user via terminal.

Below is an example to set user name and user gmail for a user.

git config --global user.name "usera"
git config --global user.email "usera@gmail.com"

The settings will be written to ~/.gitconfig file.  After the commands, all git repositories by default will have user name of "usera" and user email as "usera@gmail.com.

Web access in Swift 3

Xcode 8.2.1 is used for the development of web access below.

Use UIWebView to load a webpage or display html string. Let's define an IBOutlet for a UIWebView component as following.

    @IBOutlet weak var webView: UIWebView!

1. Use loadRequest to load a URL request.

        if let myURL = URL(string:"https://stackoverflow.com") {   
            /// Use loadRequest to load a URL
            webView.loadRequest(URLRequest(url: myURL))
        }

2. Use loadHTMLString to display HTML string.

        ///Use loadHTMLString to diplay HTML string in web view.
        webView.loadHTMLString("<h1>Hello</h1>", baseURL: nil)

Sometimes we need to get the contents of a URL to do some parsing. Below is an example to use the dataTask function of a URLSession to load the contents of a URL

        ///Use dataTask function to get contents for a URL
        if let myURL = URL(string:"https://stackoverflow.com") {
            let task = URLSession.shared.dataTask(with: myURL, completionHandler: {
                (data, respose, error) in
                
                if error != nil {
                    print(error as Any)
                } else {
                    if let unwrappedData = data {
                        let strData = NSString(data: unwrappedData, encoding: String.Encoding.utf8.rawValue)
                            as! String
                        print(strData)
                    }
                }
            })
            task.resume()
        }

We can also use URLRequest in dataTask function to get the contents of a URL, which is quite similar.

        ///Use dataTask function for a URL request
        if let myURL = URL(string:"https://stackoverflow.com") {
            let myRequest = URLRequest(url: myURL)
            let task = URLSession.shared.dataTask(with: myRequest, completionHandler: {
                (data, response, error) in
                
                if error != nil {
                    print(error as Any)
                } else {
                    if let unwrappedData = data {
                        let strData = NSString(data: unwrappedData, encoding: String.Encoding.utf8.rawValue)
                            as! String
                        print(strData)
                    }
                }
            })
            task.resume()
        }

The former seems to be more straightforward.

For security reasons, insecure http access is not allowed. Ref[1] talked about details on adding exception domains into.plist. An example to add stackoverflow.com and all its subdomains is below.

<key>NSAppTransportSecurity</key>
<dict>
  <key>NSAllowsArbitraryLoads</key>
  <false/>
  <key>NSExceptionDomains</key>
  <dict>
    <key>stackoverflow.com</key>
    <dict>
      <key>NSIncludesSubdomains</key>
      <true/>
      <key>NSExceptionAllowsInsecureHTTPLoads</key>
      <true/>
    </dict>
  </dict>
</dict>

References

-----------

1. How to Add App Transport Security Exception Domains, 

https://cocoacasts.com/how-to-add-app-transport-security-exception-domains/

Swipe Actions for UITableViewCell

There are two references Ref[1,2] on swipe actions for UITableViewCell. Things have changed a bit for iOS 8.2.

For example, the following function is not needed for UITableView's delegate to make rows editable. By default, the rows are editable.

    
    func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        return true
    }

To disable rows from editing, we can return false for the above function.

Ref[2] illustrates how to delete a row. For Xcode 8.2, the corresponding code snippet is below

    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == UITableViewCellEditingStyle.delete {
            todoList.remove(at: indexPath.row)
            tableView.deleteRows(at: [indexPath], with: UITableViewRowAnimation.automatic)
        }
    }

We can also use editActionsForRowAt to delete a row as below.

    func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
        let delAction = UITableViewRowAction(style: UITableViewRowActionStyle.default, title: "Delete") { (action, index) in
            self.todoList.remove(at: indexPath.row)
            tableView.deleteRows(at: [indexPath], with: UITableViewRowAnimation.automatic)
        }
        delAction.backgroundColor = UIColor.orange
        return [delAction]
    }

editActionsForRowAt can enable more actions for a row and is more useful.


References
--------------
1. http://www.brianjcoleman.com/tutorial-swipe-actions-for-uitableviewcell-in-swift/
2. https://www.ioscreator.com/tutorials/delete-rows-table-view-ios8-swift

Touch ID for iOS programming

References
--------------
1. Touch ID with Swift https://www.devfright.com/touch-id-swift/

Xcode Useful Shotcuts

Some useful shortcuts to make Xcode development more efficient.

1. Build and running

⌘ + B        Build
⇧ + ⌘ + K   Clean
⌘ + R        Run

2. Files and Windows

⌘ + F       Find text in a file 
⇧ + ⌘ + F   Find text in Project
⌘ + N       Create a new file
⌘ + T       Open a new tab
⌘ + W       Close a tab

3. Navigation

⌘ + 0        Show/Hide Navigator
⌥ + ⌘ + 0   Show/Hide Utilities

4. Editor

⌃ + I             Reindent
⎋ or ⌃ + Space   Show/Hide completion

5. Others

⌥ + Click or Force Click    Quick help for class or method name that was clicked.
⌘ + Click                   Go to the definition of the class that was clicked.

Mac commonly used shortcuts

Ref[1] contains a complete list of MacOS shortcuts. Here I list a few commonly used ones from it.

Fn–Up Arrow         Page Up: Scroll up one page. 
Fn–Down Arrow       Page Down: Scroll down one page.
Fn–Left Arrow       Home: Scroll to the beginning of a document.
Fn–Right Arrow      End: Scroll to the end of a document.
Command–Up          Arrow Move the insertion point to the beginning of the document.
Command–Down Arrow  Move the insertion point to the end of the document.
Command–Left Arrow  Move the insertion point to the beginning of the current line.
Command–Right Arrow Move the insertion point to the end of the current line.
Control-A           Move to the beginning of the line or paragraph.
Control-E           Move to the end of a line or paragraph.

References
-------------
1. Mac Keyboard shortcuts, https://support.apple.com/en-us/HT201236

Social Sign In On iOS

References
--------------
1. Swift 3 + Firebase Authentication - Google Sign In
https://www.youtube.com/watch?v=83EXULT480Q

2. Swift 3: Firebase Social Login - Google Sign In (Ep 4)
https://www.youtube.com/watch?v=rDKtMz_PcLQ

3. Swift 3: Firebase Social Login - Facebook Authentication and Cocoapods
https://www.youtube.com/watch?v=iSszeW1aH6I

4. Swift 3: Firebase Social Login - Facebook Email and Custom Login Button (Ep 2)
https://www.youtube.com/watch?v=Tl_uCGjCZd8

5. Sign in series #2: Adding Google Sign-in to your iOS App (Route 85)
https://www.youtube.com/watch?v=QmnI5c85sf0

6.
http://stackoverflow.com/questions/39550525/firinstanceid-warning-stop-will-reset-deviceid-from-memory-xcode-console-lo/39560078#39560078

Developer's useful websites for various resources

1. various sounds and music
http://freesfx.com/
2. Make images files as icons for iOS apps
http://makeappicon.com

Swift Language Tips

References
--------------
1. The as! operator,  https://developer.apple.com/swift/blog/?id=23

User Notification

Reference
1. User Notifications in iOS 10 Tutorial,
https://www.youtube.com/watch?v=H2B-dIK2X_c