composition

问题 i'm trying to compose some functions together: compose = (...fns) => fns.reduce((f, g) => (...args) => f(g(...args))); checkAuthorization returns a promise that check if a user is authorized. buildParams receives someRequestData , and pipes the result to searchItem . checkAuthorization() .then(() => { compose( searchItem, buildParams )(someRequestData) }, (e) => { handleError(e) }) I think it's OK, but I wish to have a more elegant look for readability, something like: compose( searchItem,

问题 P is an abstract class, I want to make it member of class A which is a normal concrete class. Is it possible if yes how. Relationship is composition Thanks for help 回答1: Since P is abstract, you can never create an object of that type. However, you can store a pointer to P as a member of class A ; this pointer member could then point to an instance of a (concrete) subclass of P . 回答2: No. A composition relationship implies that class Client actually contains a member variable of type

问题 I'm using MVP pattern to develop a large scale application. While working in the development I have come up with the question whether if composition or inheritance should be used. For example: Let's assume that I have a form called Foo with fields A and B . In other part of the application I have a form Bar that has the same fields A and B but an additional field C . Currently, the code is written with the inheritance approach in where the view the form Bar inherits from form Foo . The

问题 I need a detailed explanation on the following: What do we use a UIViewController for? What is the use of it? I have a class that looks like the following: class one { UINavigationController *nav = ...; two *secondObject = ...; // By use of it, I have push the new view class two//ok } class two { ... } How can I use secondObject in the class one ? What is the class hierarchical start from the window? 回答1: The UIViewController is the controller part in the MVC design pattern. Model <------->

问题 I need a detailed explanation on the following: What do we use a UIViewController for? What is the use of it? I have a class that looks like the following: class one { UINavigationController *nav = ...; two *secondObject = ...; // By use of it, I have push the new view class two//ok } class two { ... } How can I use secondObject in the class one ? What is the class hierarchical start from the window? 回答1: The UIViewController is the controller part in the MVC design pattern. Model <------->

问题 I've recently spent a good deal of time performing detailed UML designs of various SW components that I have since written. Looking back on what I have recently finished and comparing that to when I first learned UML, I see that I now almost strictly use Aggregation and Composition relationships, and have virtually abandoned "vanilla" non-directed/directed relationships. I still of course use Generalizations and Realizations, but these are distinctly different than those above and are not

问题 Background: Composition is putting two functions together to form a third function where the output of one function is the input of the other. No matter how much I look at this I struggle with how to read it. In particular why the compose() return => (a) => captures the 121.2121212 in local scope. Also I struggle with how final fn f(g(a)) would look with all the values/fn present w/o the use of variables. Question: Does anyone have any techniques or diagrams for quickly reading examples like

问题 I am currently working on an MVC web app with MEF so that a) developers can develop plugins for the website, and users can elect which plugins they want on their account. This means that some of my composition has to happen after the app has already started and the user has logged in (which goes to the database, grabs the assemblies for the plug in and adds them to the current catalog). The way it works is I have a couple of libraries that I store in the database and pull out when the user

问题 I have a MovieClip that is composed in a parent (non-display object) class. We register an event listener against that movieclip - a CLICK handler for example. With event.target I can get a reference to the MovieClip from within the event handler. But how can I pull a reference to its composing class? I could simply add a "parentClass" property on the dynamic MovieClip class, but I'm wondering if there's a more elegant/idiomatic way of doing it that I should consider? 回答1: If the class that

问题 My previous understanding of the decorator pattern was that you inherit Window with WindowDecorator , then in the overridden methods, do some additional work before calling the Window 's implementation of said methods. Similar to the following: public class Window { public virtual void Open() { // Open the window } } public class LockableWindow : Window // Decorator { public virtual void Open() { // Unlock the window base.Open(); } } However this essentially hardcodes the decoration, so how