PHP为现有类添加了附加功能

Question

i have class and set of methods in my library.

class name is called classA which have the method call generateCSS method. in these function some set of meta TAG are defined already. now i want to add some more meta tag to the existing function generateCSS. As well these over riding should not disturb the existing function generateCSS also i want my new meta tag in that generateCSS function.

Here every one accessing generateCSS method. so my new meta tag change should reflect in that as well.

class classb extends classa{

    public function add_generateCSS (){
        parent::generateCSS();      
        return $html = "<script src='new.js'></script>";
    }   
}

Answer 1

I'm not completely sure if I understood the question right, but I think you are looking for this:

class classb extends classa{

  public function add_generateCSS (){
    $html = parent::generateCSS();      
    return $html . "<script src='new.js'></script>";
  }   
}

You were calling the generateCSS() method on the parent and then disposing the result immediately. You should save that result in a variable and concatenate your additional code to it. Then return that.