Extract Superclass
Basics
The Extract Superclass refactoring enables extracting certain members of a class into a superclass. In CLion, this refactoring is available for C++, Objective-C/C++, Python and JavaScript code.
Examples
| Before | After |
|---|---|
class SomeClass {
char SomeChar = 'a';
long d22;
//This function will be extracted to a base class
void exFunc(int);
}; | class SuperClass {
void exFunc(int);
};
class SomeClass : public SuperClass {
char SomeChar = 'a';
long d22;
}; |
| Before | After |
|---|---|
@interface SСlass : NSObject {
int v; //This variable will be extracted to a superclass
}
- (void)initV;
@end
@implementation SСlass
- (void)initV {
v = 20;
}
@end | @interface SuperClass : NSObject { int v; }
@end
@interface SСlass : SuperClass
- (void)initV;
@end
@implementation SСlass
- (void)initV {
v = 20;
}
@end |
| Before | After |
|---|---|
class BaseClass:
# This function will be extracted to a base class
def eval_smth(self, a, b, c):
x = 2*b - c
y = 2*b + c
return x, y | class SuperClass:
def eval_smth(self, a, b, c):
x = 2*b - c
y = 2*b + c
return x, y
class BaseClass(SuperClass):
pass |
| Before | After |
|---|---|
class Editor {
//This function will be extracted to a superclass
View() {
console.log(this.name + ' can view');
}
Edit() {
console.log(this.name + ' can edit');
}
} | class User {
View() {
console.log(this.name + ' can view');
}
}
class Editor extends User {
Edit() {
console.log(this.name + ' can edit');
}
} |
Extracting a superclass
To extract a superclass
- Select the desired class in one of the views, or just open it in the editor.
- On the on the main menu or on the context menu, choose .
- In the Extract Superclass dialog box that appears, specify the following information:
- Name of the new superclass.
- Members to be included in the superclass
- Proceed with the refactoring.
Extracting the class dependent members
Let's consider the following sample of code:
a and variable exRes. If you apply Extract Superclass refactoring to the above class and try to select exRes to be moved, and leave a in the base class, CLion highlights the problem member in Extract Superclass dialog, as following: 
Trying to proceed with extract, you will get the following warning message:
Choose Continue to ignore the problem and proceed with refactoring, or Cancel to return back and resolve it. Also you can observe the conflict in Find Tool Window.
Last modified: 24 July 2018