[note: This question was originally tagged as being language-agnostic. Based on that, this answer was written to be fairly language agnostic, so it discusses inheritance as it’s used across a wide range of languages, such as Smalltalk, C++, and Object Pascal. It’s since been re-tagged as being specifically about Java. Java is different in defining … Read more
Subclass Factory Mixins There is another way to realize mixins in Javascript: With subclass factories. A subclass factory is a function that excepts a base class and returns an extended subclass of this base class: const mixin = base => class extends base { /* properties to mix in */ } Subclass factories are possible … Read more
Depending on the purpose of the <ui:include> template, you’ve several options: Use <f:subview>. It creates another NamingContainer context (like as <h:form>, <h:dataTable>, and friends all do): <f:subview id=”top”> <ui:include src=”https://stackoverflow.com/WEB-INF/includes/some.xhtml” /> </f:subview> … <f:subview id=”bottom”> <ui:include src=”https://stackoverflow.com/WEB-INF/includes/some.xhtml” /> </f:subview> The components definied in some.xhtml will end up getting respectively top: and bottom: prefix in their … Read more
The easiest approach would be first to write a composition of 2 functions: def compose2(f, g): return lambda *a, **kw: f(g(*a, **kw)) And then use reduce to compose more functions: import functools def compose(*fs): return functools.reduce(compose2, fs) Or you can use some library, which already contains compose function.
Composition final class Car { private final Engine engine; Car(EngineSpecs specs) { engine = new Engine(specs); } void move() { engine.work(); } } Aggregation final class Car { private Engine engine; void setEngine(Engine engine) { this.engine = engine; } void move() { if (engine != null) engine.work(); } } In the case of composition, the … Read more
Foo f1; Foo f2(f1); Yes this will do what you expect it to: The f2 copy constructor Foo::Foo(Foo const&) is called. This copy constructs its base class and then each member (recursively) If you define a class like this: class X: public Y { private: int m_a; char* m_b; Z m_c; }; The following methods … Read more
Technically, it doesn’t matter where you declare the <f:metadata> in the view as long as it’s in the top level view (so, when using templating, in the template client and thus not in the master template). When the view get built, the metadata is basically not part of the JSF component tree, but of the … Read more
Prefer composition over inheritance as it is more malleable / easy to modify later, but do not use a compose-always approach. With composition, it’s easy to change behavior on the fly with Dependency Injection / Setters. Inheritance is more rigid as most languages do not allow you to derive from more than one type. So … Read more
No, there is no way to implement the same method in two different ways in one class in Java. That can lead to many confusing situations, which is why Java has disallowed it. interface ISomething { void doSomething(); } interface ISomething2 { void doSomething(); } class Impl implements ISomething, ISomething2 { void doSomething() {} // … Read more
Thoughts: Avoid extending JFrame as it ties your GUI to being, well a JFrame. If instead you concentrate on creating JPanels instead, then you have the freedom to use these JPanels anywhere needed — in a JFrame, or JDialog, or JApplet, or inside of another JPanel, or swapped with other JPanels via a CardLayout. Avoid … Read more