The decorator pattern is a design pattern that allows you to wrap an object such that it will appear to execute a given behavior in many different ways at different points in program execution. This is especially useful when you want an object to have different behaviors at but are unable to mutate the object. The decorator pattern is a useful way to implement dynamic behavior without needing an extended inheritance-based class hierarchy. To use the decorator pattern you need four elements: a component interface; a concrete component; a decorator abstraction; and, a concrete decorator. The interface sets the contract for both component and decorator behavior, the decorator abstraction contains a pointer to some concrete component, and the concrete decorators wrap a concrete component and override behavior if desired.
NOTE  A Property Descriptor is not provided as an argument to a property decorator due to how property decorators are initialized in TypeScript. This is because there is currently no mechanism to describe an instance property when defining members of a prototype, and no way to observe or modify the initializer for a property. The return value is ignored too. As such, a property decorator can only be used to observe that a property of a specific name has been declared for a class.
The decorator pattern, also known as the wrapper pattern, is when you wrap an object within another object, thus providing a means of enhancing or overriding certain behavior. The wrapper object will delegate any incoming method calls to the original object, unless it defines a new method to enhance or replace the original object’s behavior. By using the decorator pattern, you can dynamically create as many decorated objects as you want, each enhancing the behavior of the original object in a unique way — and all without mutating the original object. In this manner, you can effectively add, remove, or extend behaviors at runtime.
Now, assume one also desires the ability to add borders to windows. Again, the original Window class has no support. The ScrollingWindow subclass now poses a problem, because it has effectively created a new kind of window. If one wishes to add border support to many but not all windows, one must create subclasses WindowWithBorder and ScrollingWindowWithBorder etc. This problem gets worse with every new feature or window subtype to be added. For the decorator solution, we simply create a new BorderedWindowDecorator—at runtime, we can decorate existing windows with the ScrollingWindowDecorator or the BorderedWindowDecorator or both, as we see fit. Notice that if the functionality needs to be added to all Windows, you could modify the base class and that will do. On the other hand, sometimes (e.g., using external frameworks) it is not possible, legal, or convenient to modify the base class.
You saw that, to define a decorator, you typically define a function returning a wrapper function. The wrapper function uses *args and **kwargs to pass on arguments to the decorated function. If you want your decorator to also take arguments, you need to nest the wrapper function inside another function. In this case, you usually end up with three return statements.
Now, assume one also desires the ability to add borders to windows. Again, the original Window class has no support. The ScrollingWindow subclass now poses a problem, because it has effectively created a new kind of window. If one wishes to add border support to many but not all windows, one must create subclasses WindowWithBorder and ScrollingWindowWithBorder etc. This problem gets worse with every new feature or window subtype to be added. For the decorator solution, we simply create a new BorderedWindowDecorator—at runtime, we can decorate existing windows with the ScrollingWindowDecorator or the BorderedWindowDecorator or both, as we see fit. Notice that if the functionality needs to be added to all Windows, you could modify the base class and that will do. On the other hand, sometimes (e.g., using external frameworks) it is not possible, legal, or convenient to modify the base class.
The decorator pattern can be used to extend (decorate) the functionality of a certain object statically, or in some cases at run-time, independently of other instances of the same class, provided some groundwork is done at design time. This is achieved by designing a new Decorator class that wraps the original class. This wrapping could be achieved by the following sequence of steps:
Now we have our logit decorator in production, but when some parts of our application are considered critical, failure might be something that needs more immediate attention. Let’s say sometimes you want to just log to a file. Other times you want an email sent, so the problem is brought to your attention, and still keep a log for your own records. This is a case for using inheritence, but so far we’ve only seen functions being used to build decorators.

Land Union invests in hotel properties and operates them through its sister company Ming Hotels. Land Union specialises in city hotels in the 5-star category ranging from 50 to 150 rooms. Only prime locations are considered. As a family-run business operating in a niche market, our hotels differentiate clearly from sterile large hotel chains; instead, we aim to offer thoughtful comfort, individuality, service, and experience. For our Hotel in Soho we are currently seeking part time maintenance technician. You need to be proactive and have excellent communication skills, also you need experience of working as a maintenance technician in a busy hotel environment. Maintenance Technician Role To carry out all types of repairs to equipment, fixtures and fittings. Responsibility of all tools, materials used in connection with main duties. Liaison with contractors and other key stakeholders. To undertake plumbing, carpentry, painting and mechanical work as necessary to maintain safe and efficient system within the hotel. To respond to maintenance requests on ord

Experience is more important than qualifications when attempting to find work. Working as a mate, or completing an apprenticeship, are both good ways to get this initial experience. If working independently as a self-employed person, experience is also necessary in order to be aware of the standard of work expected. A bad job will be easily noticed, and may lead to difficulty finding further work. When already working for a company, more in-depth courses can be completed in order to gain experience, which can sometimes lead to increases in salary. These courses could include:
You saw that, to define a decorator, you typically define a function returning a wrapper function. The wrapper function uses *args and **kwargs to pass on arguments to the decorated function. If you want your decorator to also take arguments, you need to nest the wrapper function inside another function. In this case, you usually end up with three return statements.

Painter & Decorator - The Berkeley In fashionable Knightsbridge, The Berkeley is one of the leading 5-star hotels in London; breath-taking luxury hotel suites fuse comfort, stylish design and the latest innovations; a heavenly swimming pool and luxury spa provide a seventh-floor retreat overlooking Hyde Park. The stars come out for award-winning cocktails at the Blue Bar, and fashionistas join us for Prêt-à-Portea, our catwalk-inspired London afternoon tea in our Collins Room. The Berkeley forms part of the Maybourne Hotel Group, London's ultra-luxury hotel company. A career with Maybourne Hotel Group will put you side by side with people who amaze our guests with individual experiences and aim for perfection in everything they do. Role Description: As Painter and Decorator in our hotel you will be responsible for upholding our beautiful bedrooms to a pristine condition.Variety is the key to your work, as many rooms are individually designed and decorated to ensure you always have a challenge. You will ensure the paint work is neat throughout the building and you will also be required to carry out wallpapering work and tiling throughout the entire building.
Moreover, the use of language is only an abstraction for a color equivalent. The word "red", for example, can cover a wide range of variations from the pure red of the visible spectrum of light. There is not a formalized register of different colors in the way that there is agreement on different notes in music, such as F or C♯. For a painter, color is not simply divided into basic (primary) and derived (complementary or mixed) colors (like red, blue, green, brown, etc.).
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