ArticleZip > Better Way To Call Superclass Method In Extjs

Better Way To Call Superclass Method In Extjs

When working with ExtJS, understanding how to call superclass methods is essential for building robust and scalable applications. In this article, we will explore a better way to call superclass methods in ExtJS, which can help you write cleaner and more maintainable code.

When you extend a class in ExtJS, you often need to override methods defined in the superclass. However, there are cases where you want to call the superclass method inside the overridden method to reuse its functionality. In traditional JavaScript, you can use the `callParent` method to achieve this.

The `callParent` method is a convenient way to call the superclass method within an overridden method. It ensures that the superclass method is executed in the correct context, allowing you to access properties and methods defined in the superclass. Here's how you can use `callParent` in your ExtJS classes:

Javascript

Ext.define('MyApp.override.MyClass', {
    override: 'MyApp.MyClass',

    myMethod: function() {
        // Call the superclass method
        this.callParent();

        // Add your custom logic here
    }
});

In the example above, `callParent` is called inside the `myMethod` of the `MyClass` class override. This ensures that the superclass method of `myMethod` is executed before your custom logic. This approach helps you avoid repeating code and promotes code reusability.

While `callParent` is a handy tool, it has some limitations, especially when dealing with multiple levels of inheritance. In such cases, using the `getParent` method provides a more flexible solution.

The `getParent` method allows you to access the superclass of a class dynamically, regardless of the depth of the inheritance chain. This can be useful when you need to call a method defined in a specific superclass, rather than the immediate superclass. Here's how you can use `getParent`:

Javascript

Ext.define('MyApp.override.MyClass', {
    override: 'MyApp.MyClass',

    myMethod: function() {
        // Call the superclass method
        this.getParent().myMethod.call(this);

        // Add your custom logic here
    }
});

In the updated example, `getParent` is used to access the superclass of `MyClass` dynamically and call its `myMethod`. This approach offers more control when dealing with complex class hierarchies.

In conclusion, knowing how to call superclass methods in ExtJS is crucial for effective code organization. By leveraging tools like `callParent` and `getParent`, you can streamline your development process and build more maintainable applications. Experiment with these techniques in your ExtJS projects to discover the best approach that suits your needs. Happy coding!

Related posts:

×