tclementdev

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

• You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

• Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

arturgrigor

# Uncomment the next line to define a global platform for your project
# platform :ios, '9.0'

target '%TargetName%' do
  # Comment the next line if you're not using Swift and don't want to use dynamic frameworks
  use_frameworks!

  # Pods for %TargetName%
  # pod 'FBSDKCoreKit'
end

kastiglione

extension UIView {
    /// Example: call someView.nudge(0, 30)
    func nudge(_ dx: CGFloat, _ dy: CGFloat) {
        self.frame = self.frame.offsetBy(dx: dx, dy: dy)
        CATransaction.flush()
    }
}

extension UIView {
    /// Example: po UIView.root

danielmartin

If you work on a Swift project that follows the Model-View-ViewModel (MVVM) architecture or similar, you may want to jump to counterpart in Xcode from your view to your model, and then to your view model. (ie. by using Ctrl+Cmd+Up and Ctrl+Cmd+Down).

You can do this in recent versions of Xcode by setting a configuration default.

From a terminal, just type this command and press Enter:

defaults write com.apple.dt.Xcode IDEAdditionalCounterpartSuffixes -array-add "ViewModel" "View"

beefon

setopt extended_glob

removeDerivedData() {
    local project_name=$1
    if [[ -z "$project_name" ]]
    then
        rm -rf ~/Library/Developer/Xcode/DerivedData/*/^Index
    else
        rm -rf ~/Library/Developer/Xcode/DerivedData/"$project_name"*/^Index
    fi