CLion 2018.2 Help

Extract Superclass

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

BeforeAfter
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; };
BeforeAfter
@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
BeforeAfter
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
BeforeAfter
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

  1. Select the desired class in one of the views, or just open it in the editor.
  2. On the on the main menu or on the context menu, choose Refactor | Extract | Superclass.
  3. In the Extract Superclass dialog box that appears, specify the following information:
    • Name of the new superclass.
    • Members to be included in the superclass
      cl extractSuperclassDialog
  4. Proceed with the refactoring.

Extracting the class dependent members

Let's consider the following sample of code:
cl extractSuperclassError1
As you can see, there is a dependency between array 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:
cl extractSuperclassError2

Trying to proceed with extract, you will get the following warning message:

cl extractSuperclassError3

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: 16 June 2018

See Also