Tutorial by Examples: custome

Under most circumstances, it is simpler from a code-design standpoint to use existing generic Exception classes when throwing exceptions. This is especially true if you only need the exception to carry a simple error message. In that case, RuntimeException is usually preferred, since it is not a che...

In Go, an error is represented by any value that can describe itself as string. Any type that implement the built-in error interface is an error. // The error interface is represented by a single // Error() method, that returns a string representation of the error type error interface { Erro...

A custom exception is any class that extends Exception or a subclass of Exception. In general, you should always extend StandardError or a descendant. The Exception family are usually for virtual-machine or system errors, rescuing them can prevent a forced interruption from working as expected. # ...

A custom extraction can be written by implementing the unapply method and returning a value of type Option: class Foo(val x: String) object Foo { def unapply(foo: Foo): Option[String] = Some(foo.x) } new Foo("42") match { case Foo(x) => x } // "42" The retur...

You are allowed to implement custom exceptions that can be thrown just like any other exception. This makes sense when you want to make your exceptions distinguishable from other errors during runtime. In this example we will create a custom exception for clear handling of problems the application ...

Create a class inheriting from Exception: class FooException(Exception): pass try: raise FooException("insert description here") except FooException: print("A FooException was raised.") or another exception type: class NegativeError(ValueError): pass ...

package { import flash.events.Event; public class CustomEvent extends Event { public static const START:String = "START"; public static const STOP:String = "STOP"; public var data:*; public function CustomEvent(type:Strin...

Creating a Custom Element with bindable properties is a snap. If you want to create an element that accepts one or more values which the plugin can use, the @bindable decorator and syntax is what you are looking for. Below, we are creating a custom element that accepts an array of fruits and displa...

In the following, we are creating an example of an Aurelia Custom Element which will allow you to display Youtube videos via their video ID. An Aurelia Custom Element can be defined in two different ways: the first one is by creating a viewmodel and accompanying view, the second one is by just cre...

A basic custom element is created in Aurelia based on naming conventions, by simply adding the suffix CustomElement to the name of a class. This suffix will automatically be stripped out by Aurelia. The remaining part of the class name will be lowercased and separated using a hyphen and can then be ...

.htaccess can be used to set a custom error pages that matches the theme of your website instead of seeing a white error page with black techno-babble when users end up on at a page with an error server response code. The error page can be any browser parseable file, including (But not limited to)...

use std::error::Error; use std::fmt; use std::convert::From; use std::io::Error as IoError; use std::str::Utf8Error; #[derive(Debug)] // Allow the use of "{:?}" format specifier enum CustomError { Io(IoError), Utf8(Utf8Error), Other, } // Allow the use of "{...

$this->helper('customer/data')->getAccountUrl(); OR Mage::helper('customer/data')->getAccountUrl();

Mage::helper('customer')->getCustomer(); or Mage::getSingleton('customer/session')->getCustomer();

Implementing the IEnumerable interface allows classes to be enumerated in the same way as BCL collections. This requires extending the Enumerator class which tracks the state of the enumeration. Other than iterating over a standard collection, examples include: Using ranges of numbers based on a...

In most examples, the class naming convention is used to define an Aurelia Custom Element. However, Aurelia also provides a decorator that can be used to decorate a class. The class is again treated as a custom element by Aurelia then. The value supplied to the decorator becomes the name of the cus...

Custom events usually need custom event arguments containing information about the event. For example MouseEventArgs which is used by mouse events like MouseDown or MouseUp events, contains information about Location or Buttons which used to generate the event. When creating new events, to create a...

Often when writing a specialized class, you'll want it to raise its own specific errors, and you'll want a clean way for user/calling code to handle these custom errors. A neat way to achieve this is by defining a dedicated Enum type: Option Explicit Public Enum FoobarError Err_FooWasNotBarre...

class CustomException implements Exception { String cause; CustomException(this.cause); } void main() { try { throwException(); } on CustomException { print("custom exception is been obtained"); } } throwException() { throw new CustomException('This is m...

package org.bookmytickets.controller; import java.util.List; import org.bookmytickets.model.Customer; import org.bookmytickets.repository.CustomerRepository; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.PathVariable; import o...