How to override trait function and call it from the overridden function

Question

Scenario   trait A       function calc  v            return  v 1           class MyClass       use A       function calc  v             v            return A  calc  v            print  new MyClass   - gt calc 2      should print 4   This code doesn t work  and I cannot find a way to call a trait function like it was inherited  I tried calling self  calc  v   static  calc  v   parent  calc  v   A  calc  v  and the following   trait A       function calc  v            return  v 1           class MyClass       use A           calc as traitcalc             function calc  v             v            return traitcalc  v             Nothing works     Is there a way to make it work or must I override completely the trait function which is much more complex than this

User · Answer

An alternative approach if interested - with an extra intermediate class to use the normal OOO way  This simplifies the usage with parent  methodname   trait A       function calc  v            return  v 1              an intermediate class that just uses the trait class IntClass       use A        an extended class from IntClass class MyClass extends IntClass       function calc  v             v            return parent  calc  v

User · Answer

Using another trait   trait ATrait       function calc  v            return  v 1           class A       use ATrait     trait BTrait       function calc  v             v            return parent  calc  v            class B extends A       use BTrait     print  new B   - gt calc 2      should print 4

User · Answer

Your last one was almost there   trait A       function calc  v            return  v 1           class MyClass       use A           calc as protected traitcalc             function calc  v             v            return  this- gt traitcalc  v             The trait is not a class  You can t access its members directly  It s basically just automated copy and paste

User · Answer

Another variation  Define two functions in the trait  a protected one that performs the actual task  and a public one which in turn calls the protected one  This just saves classes from having to mess with the  use  statement if they want to override the function  since they can still call the protected function internally  trait A       protected function traitcalc  v            return  v 1             function calc  v            return  this- gt traitcalc  v            class MyClass       use A       function calc  v             v            return  this- gt traitcalc  v            class MyOtherClass       use A      print  new MyClass   - gt calc 2      will print 4  print  new MyOtherClass   - gt calc 2      will print 3

User · Answer

If the class implements the method directly  it will not use the traits version   Perhaps what you are thinking of is   trait A       function calc  v            return  v 1           class MyClass       function calc  v            return  v 2           class MyChildClass extends MyClass     class MyTraitChildClass extends MyClass      use A     print  new MyChildClass   - gt calc 2      will print 4  print  new MyTraitChildClass   - gt calc 2      will print 3   Because the child classes do not implement the method directly  they will first use that of the trait if there otherwise use that of the parent class   If you want  the trait can use method in the parent class  assuming you know the method would be there  e g   trait A       function calc  v            return parent  calc  v 3                   other code from above print  new MyTraitChildClass   - gt calc 2      will print 8  2 3   2    You can also provide for ways to override  but still access the trait method as follows   trait A       function trait calc  v            return  v 3           class MyClass       function calc  v            return  v 2            class MyTraitChildClass extends MyClass      use A         A  trait calc as calc            class MySecondTraitChildClass extends MyClass      use A         A  trait calc as calc             public function calc  v          return  this- gt trait calc  v   5            print  new MyTraitChildClass   - gt calc 2      will print 6 echo   n   print  new MySecondTraitChildClass   - gt calc 2      will print 6 5   You can see it work at http   sandbox onlinephpfunctions com code e53f6e8f9834aea5e038aec4766ac7e1c19cc2b5

[php] How to override trait function and call it from the overridden function?

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