UIZE JavaScript Framework

2012 NEWS 2012-08-05 - New is Instance Method for Classes

The new is instance method, implemented in the Uize.Class base class module, provides a semantically elegant way to test if the value of an instance's state property is truthy.


myInstance.is (propertyNameSTR);

The is method returns a boolean, indicating whether or not the specified state property's value is truthy. This method is offered as a convenience to improve the semantics of code that is using state properties to represent conditions, and is a very thin wrapper around the get instance method. The statement myInstance.is ('myCondition') is equivalent to the statement !!myInstance.get ('myCondition').


if (myWidget.is ('enabled')) {
  // do something if the widget is enabled

In the above example, some code is being executed conditionally, based upon whether or not a widget is enabled. The Uize.Widget base class provides an enabled state property, whose value is a boolean. One could use the get method in this code example to achieve the same effect, but using the is method make the code more readable.