overriding

问题 I have made some changes to Mage_Core_Controller_Request_Http but in the file distributed by with magento. This is not the best way, i know, but i have not been able to work out how to override a file in the Controller directory. I can find out how to override files in the controllers directory. Can anyone tell me how i can override Mage_Core_Controller_Request_Http in my own extension. thanks 回答1: If you don't want to revert to the include path hack, you can also use reflection to set your

问题 I want to validate value before every model save. So, I must override the save function. The code is nearly just the same on, and I want to write it in a mixin class. But failed for I don't know how to write super func. I'm poor of of English, so sorry. class SyncableMixin(object): def save(self, *args, **kwargs): try: res = validate(*args, **kwargs) except Exception: raise ValidateException() super(?, self).save(*args, **kwargs) class SomeModel(SyncableMixin, models.Model): pass 回答1: You

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 7 years ago . how to implement such a functionality to access private members ? Java checks access permissions during compilation only. Are you surprised? I was surprised very much to find out this fact. So you can create

问题 Say I have two files, file1.py and file2.py . In file1.py , I define two classes, one inherits from the other: file1.py: class Class1: def __init__(self): pass def func1(self): return "Hello world!" class Class2(Class1): def __init__(self): pass def func2(self): return self.func1() So now I'm able to call func1() and func2() from Class2 . file2.py: import file1 class Class3(file1.Class2): def __init__(self): pass Question: How can I change func1() from Class1 in file2.py , so that func2() in

问题 How to override a magic method for the current script? def __setattr__(name, value): __dict__[name] = value print("asd") if name == 'b': print(__dict__[name]) if __name__ == '__main__': a = 3 b = 4 b = 5 In above, for example, I expect assignments to b to call __setattr__ but they don't. What am I missing? 回答1: __setattr__ only applies to assignments of the form a.b = c , which translates to type(a).__setattr__(b, c) . Simple name assignments are a fundamental operation of the language itself

问题 Look at the following code snippet: class A { void fun1() { System.out.println("fun1 of A"); fun2(); } void fun2() { System.out.println("fun2 of A"); } } class B extends A { void fun2() { System.out.println("fun2 of B"); } } in main method: A a=new B(); a.fun1() The output is: fun1 of A fun2 of B Can you please explain this output. According to me a.fun1 is calling fun1 of A since fun1 is not overriden by B (otherwise it would have called fun1 of B ). And, fun2() in fun1 of A is calling fun2

问题 Hope anyone can help, i am learning Java and as comparable to anyone else in this forum i guess i am a newbie to programming as well. I have come across a chapter on abstract class and methods but don't really fully understand what they are used for and why, and thought i would get an explanation from someone who is an experienced programmer. Below i have example code i have been working on, with the help from this book, what i am not sure about is why in the class Dims do i have to have

问题 Well, it is as simple as the title. I tried for many hours to make a method that will take the archive file and a File[] (the files that will be added to the archive) and I only made it to the point that the method adds new files into the archive, but if a file with the same name of a file that I'm trying to add already exists, it throws me an error. I tried searching for a solution but didn't find any. Can you help me make a method that will take two parameters: File archive, File[]

问题 How can every set method in python's list object be overridden in a derived object such that every item in that list is of a specific class? Consider class Index(int): pass class IndexList(list): def __init__(self, int_list): for el in int_list: self.append(Index(el)) def __setitem__(self, key, val): super(IndexList, self).__setitem__(key, Index(val)) # override append insert etc... Can this be done without directly overriding every single function that adds elements to the list? I expected

问题 This question already has answers here : How to make the jvm load my java.lang.String instead of the one in rt.jar (2 answers) Closed 5 years ago . Basically I want to replace the Canvas class at runtime by an application that uses my custom Canvas class, I heard xbooting can do this but there are no tutorials or anything. So I'm just wondering what the vm arguments are, can you help me please? 回答1: By xboooting you probably mean the -Xbootclasspath parameter? You can use the -Xbootclasspath