Is there a way to create a private method in XBL?
--update
The only documentation on MDN says nothing about private methods, but it's a wiki that's not always complete..
The answer to your question is that XBL does not support private methods. However, this doesn't mean that you simply have to leave your public methods openly exposed and just accept this situation without a fight. there are some options that you have at your disposal that can help communicate that a method is private or help discourage using or modifying them:
Use an underscore in method names:
Mozilla recommends using an underscore to mark methods and fields as private. Additionally, many JavaScript libraries use underscores in the methods that the developers wish to mark as private. Although a novice developer could ignore this and still invoke the method, most people who have some basic experience with JavaScript libraries, Firefox Extension development, or JavaScript in general should know what you mean when you have a method preceded by an underscore.
Use inheritance to hide private methods:
Out of sight, out of mind.
In some languages, functionality that is common to a series of subclasses is oftentimes moved to a base abstract class. In the subclass, the inherited methods won't be seen in the subclass code.
Although this is definitely not "private", you could encapsulate your "private" methods in an XBL binding and place your public methods in an XBL binding that extends the parent binding. Inheritance is one of the most powerful features of XBL, and this could help protect your private methods from being used simply because they won't appear in the XBL binding the developer is directly interacting with.
You could then put extensive comments in the parent that describes the purpose of the "private" functionality and that it isn't meant to be public.
Keep in mind that even if you could mark a method as private, this still won't stop someone who is determined. One could still simply mark the method as "public" and use it anyway.
Here is documentation on XBL, which asserts that methods are private, and also discusses inheritance:
https://developer.mozilla.org/en/XUL_School/Custom_XUL_Elements_with_XBL
Related
I am using the AutoDataAttribute class within AutoFixture.Xunit2 in a lot of projects. The recommended approach to add your own customizations seems to be a derived attribute like the following (note I am using FakeItEasy):
public class AutoFakeItEasyDataAttribute : AutoDataAttribute
{
public AutoFakeItEasyDataAttribute()
: base(() => new Fixture().Customize(new DomainCustomization()))
{
}
}
In an effort to reduce code copying/pasting, I wanted to abstract this derived attribute to a package we could consume in our projects. However, despite attempts utilizing dependency injection with this library and running into CLR issues with the DataAttribute not able to take anything beyond basic "primitives", I have ran into the proverbial "brick-wall". Obviously constructor injection doesn't seem to work here nor property injection to my knowledge (although unlikely that matters as the property isn't allocated until after the constructor call anyway).
The bottom line, I am looking for a way to include this derived attribute into a package but in a way where the domains can be customized for each individual project's needs?
I don't think what you're trying to achieve is possible due to how attributes work in C#. As you mentioned yourself you cannot pass into the attributes but a small set of primitive values, and in xUnit 2 data attributes don't have access to the test class instance, so you can not inject instances via reflection.
You could theoretically inject the IFixture instance into the test class using the library you mentioned (which I think is a horrible practice, that promotes sloppier tests), but then you'd have to give up the decorator notation of AutoFixture and use the declarative notation, to create your test data.
I'd like to ask what are your thought on deprecation of the TableRegistry::get() static call in CakePHP 3.6?
In my opinion it was not a good idea.
First of all, using LocatorAwareTrait is wrong on many levels. Most important, using traits in such way can break the Single Responsibility and Separation of Concerns principles. In addition some developers don't want to use traits as all because they thing that it breaks the object oriented design pattern. They prefer delegation.
I prefer to use delegation as well with combination of flyweight/singleton approach. I know that the delegation is encapsulated by the LocatorAwareTrait but the only problem is that it exposes the (get/set)TableLocator methods that can be used incorrectly.
In other words if i have following facade:
class Fruits {
use \Cake\ORM\Locator\LocatorAwareTrait;
public function getApples() { ... }
public function getOranges() { ... }
...
}
$fruits = new Fruits();
I don't want to be able to call $fruits->getTableLocator()->get('table') outside of the scope of Fruits.
The other thing you need to consider when you make such changes is the adaptation of the framework. Doing TableRegistry::getTableLocator()->get('table') every time i need to access the model is not the best thing if i have multiple modules in my application that move beyond simple layered architecture.
Having flyweight/singleton class like TableRegistry with property get to access desired model just makes the development more straight forward and life easier.
Ideally, i would just like to call TR::get('table'), although that breaks the Cake's coding standards. (I've created that wrapper for myself anyways to make my app bullet proof from any similar changes)
What are your thoughts?
In my project I'm using C++/CLI and Windows Forms. I have two Forms. One is executed in main()
Application::EnableVisualStyles();
Application::SetCompatibleTextRenderingDefault(false);
Application::Run(gcnew FormA);
Another FormB is executed from the instance of FormA
FormB^ fb = gcnew FormB();
fb->Show();
I need to change components of FormB from FormA. Normally they are in private: section of class FormB. Is there any nice way to do that different from simply making them all public? In Native C++ I would use friend class but it's not allowed in C++/CLI.
C++/CLI has an access modifier that native C++ does not have. You are looking for internal:
Empowered by the strong support for modules in .NET. It is broader than friend but you have a pretty hard guarantee that whomever is messing with your private parts is never more than a few cubicles away from yours. Code that accesses internal members must be compiled into the same assembly. So your FormB class must be in the same project as your FormA class. The common case.
If you need the equivalent of friend across modules then you need the [InternalsVisibleTo] attribute. Exposing members with a public property would be another common way.
While providing public access to FormB's members may seem like a quick and easy solution, I would advise you to add some methods on FormB to perform said actions.
This way, you can call those methods from FormA, and at the same time retain proper encapsulation.
Hope this helps.
I know that non static methods cannot be referenced from some static context, you have to make an instance of the class and call the method on that instance, or , you can make the method static. I also know the reason why. But I cannot decide what is the best practice to do this? Making the method/variable static or using instance of the class to call the method/variable, and why?
Object oriented languages work best when you use objects. If its anything more than the most basic of applications, create a class to house the functionality and instantiate it. You'll just end up refactoring into classes later anyway.
The reason is that objects, instances, etc all describe varying degrees of scope, allowing you to create complex programs from an amalgamation of encapsulated, fairly simple functionalities
What are the pros and cons of having multiple inheritance?
And why don't we have multiple inheritance in C#?
UPDATE
Ok so it is currently avoided because of the issue with clashes resolving which parent method is being called etc. Surely this is a problem for the programmer to resolve. Or maybe this could be resolve simularly as SQL where there is a conflict more information is required i.e. ID might need to become Sales.ID to resolve a conflict in the query.
Here is a good discussion on the pitfalls of multiple inheritance:
Why should I avoid multiple inheritance in C++?
Here is a discussion from the C# team on why they decided not to allow multiple inheritance:
http://blogs.msdn.com/csharpfaq/archive/2004/03/07/85562.aspx
http://dotnetjunkies.com/WebLog/unknownreference/archive/2003/09/04/1401.aspx
It's just another tool in the toolbox. Sometimes, it is exactly the right tool. If it is, having to find a workaround because the language actually prohibits it is a pain and leads to good opportunities to screw it up.
Pros and cons can only be found for a concrete case. I guess that it's quite rare to actually fit a problem, but who are the language designers to decide how I am to tackle a specific problem?
I will give a pro here based on a C++ report-writer I've been converting to REALbasic (which has interfaces but only single-inheritance).
Multiple inheritance makes it easier to compose classes from small mixin base classes that implement functionality and have properties to remember state. When done right, you can get a lot of reuse of small code without having to copy-and-paste similar code to implement interfaces.
Fortunately, REALbasic has extends methods which are like the extension methods recently added to C# in C# 3.0. These help a bit with the problem, especially as they can be applied to arrays. I still ended up with some class hierarchies being deeper as a result of folding in what were previously multiply-inherited classes.
The main con is that if two classes have a method with the same name, the new subclass doesn't know which one to call.
In C# you can do a form of multiple inheritance by including instances of each parent object within the child.
class MyClass
{
private class1 : Class1;
private class2: Class2;
public MyClass
{
class1 = new Class1;
class2 = new Class2;
}
// Then, expose whatever functionality you need to from there.
}
When you inherit from something you are asserting that your class is of that (base) type in every way except that you may implement something slightly differently or add something to it, its actually extremely rare that your class is 2 things at once. Usually it just has behavour common to 2 or more things, and a better way to describe that generally is to have your class implement multiple interfaces. (or possibly encapsulation, depending on your circumstances)
It's one of those help-me-to-not-shoot-myself-in-the-foot quirks, much like in Java.
Although it is nice to extend fields and methods from multiple sources (imagine a Modern Mobile Phone, which inherits from MP3 Players, Cameras, Sat-Navs, and the humble Old School Mobile Phone), clashes cannot be resolved by the compiler alone.