Swizzling Ios

What is Swizzling in iOS?

Swizzling is the act of changing the functionality of a method by replacing the implementation of that method with another, usually at runtime.

There are many different reasons one might want to use swizzling: introspection, overriding default behavior, or maybe even dynamic method loading..

What happens when you invoke a method on a nil pointer?

In Objective-C, it is valid to send a message to nil — it simply has no effect at runtime. … If the method returns any pointer type, any integer scalar of size less than or equal to sizeof(void*) , a float , a double , a long double , or a long long , then a message sent to nil returns 0 .

How do push notifications work iOS?

Follow these steps:iOS requests a device token from Apple Push Notification Service (APNS).The app receives the token, which functions as the address to send a push notification to.The app sends the token of the device to your server.More items…

What is firebase Swizzling?

The FCM SDK performs method swizzling in two key areas: mapping your APNs token to the FCM registration token and capturing analytics data during downstream message callback handling. Developers who prefer not to use swizzling can disable it by adding the flag FirebaseAppDelegateProxyEnabled in the app’s Info.

What is Fcmtoken?

An FCM Token, or much commonly known as a registrationToken like in google-cloud-messaging. As described in the GCM FCM docs: An ID issued by the GCM connection servers to the client app that allows it to receive messages. Note that registration tokens must be kept secret.

What is the difference between Swift 4 and 5?

Swift 5 is source compatible with Swift 4.2, but isn’t binary compatible with earlier Swift releases. However, future releases will be binary compatible with Swift 5 thanks to ABI stability. … You’ll find Swift Evolution proposal numbers like [SE-0001] in each section of the tutorial.

What is dynamic dispatch in IOS?

In Swift, dynamic dispatch calls are implemented by looking up a function from a method table and then performing an indirect call. This is slower than performing a direct call. Additionally, indirect calls also prevent many compiler optimizations, making the indirect call even more expensive.

What is method Swizzling in Swift?

Peter Steinberger. iOS Development Swift. Swizzling (other languages call this “monkey patching”) is the process of replacing a certain functionality or adding custom code before the original code is called. For example, you could swizzle UIViewController.

Do not disable method Swizzling?

Method swizzling in Firebase Cloud Messaging Developers who prefer not to use swizzling can disable it by adding the flag FirebaseAppDelegateProxyEnabled in the app’s Info. plist file and setting it to NO (boolean value).

What is dynamic keyword in Swift?

Dynamic dispatch. It simply means that the Objective-C runtime decides at runtime which implementation of a particular method or function it needs to invoke. … Swift uses the Swift runtime whenever possible. The result is that it can make a number of optimizations.

Is swift dynamic or static?

But Swift itself is static, and in fact is explicitly designed in order to minimize or eliminate the use of Objective-C-type dynamism. Swift itself, is statically typed. When used with Cocoa, you get access to the objective-c runtime library which gives you the ability to use dynamic classes, messages and all.