Constructors and prototypes
From Yate Documentation
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MyConstructor.prototype = new Object; | MyConstructor.prototype = new Object; | ||
</pre> | </pre> | ||
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Now shared properties and methods can be added to the prototype: | Now shared properties and methods can be added to the prototype: | ||
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<pre> | <pre> | ||
MyConstructor.prototype.SharedProperty = 1; | MyConstructor.prototype.SharedProperty = 1; | ||
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'''IMPORTANT:''' There's a semicolon after the closing brace as this is an assignment and not a function declaration | '''IMPORTANT:''' There's a semicolon after the closing brace as this is an assignment and not a function declaration | ||
| + | ===Accessing the prototype=== | ||
| + | |||
| + | Javascript does not provide a standard way of accessing an object's prototype. | ||
| + | |||
| + | Yate uses a widespread extension of an '''__proto__''' attribute to access the prototype: | ||
| + | |||
| + | <pre> | ||
| + | Engine.print_r(this.__proto__); | ||
| + | </pre> | ||
'''See also''' | '''See also''' | ||
Revision as of 20:43, 6 February 2013
The Javascript language does not have classes, it supports only objects. However, a common behavior of objects can be implemented using prototypes.
Adding class properties and methods
Even if objects are not class members they can share a set of common properties and methods.
Currently Yate does not automatically provide a prototype for objects. This can be added easily to a constructor:
function MyConstructor()
{
this.MyProperty = 0;
}
MyConstructor.prototype = new Object;
Now shared properties and methods can be added to the prototype:
MyConstructor.prototype.SharedProperty = 1;
MyConstructor.prototype.MyMethod = function(x)
{
return x + this.MyProperty;
};
IMPORTANT: There's a semicolon after the closing brace as this is an assignment and not a function declaration
Accessing the prototype
Javascript does not provide a standard way of accessing an object's prototype.
Yate uses a widespread extension of an __proto__ attribute to access the prototype:
Engine.print_r(this.__proto__);
See also
External links
