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CookbookRecipe1
Point Example
Source
Class("Point", {
has: {
x: {is: ro},
y: {is: rw},
},
methods: {
clear: function () {
this.x = 0;
this.setY(0);
}
}
})
Class("Point3D", {
isa: Point,
has: {
z: {}
},
after: {
clear: function () {
this.z = 0;
}
}
})
var point = new Point3D();Description
This is the classic point example. In Joose classes are created using the Class() function. The function takes two parameters: The class name and the class definition which is passed as an object literal (The stuff between the outermost {}).
Classes are defined using an easy to read and easy to write declarative syntax. Keywords like "has", "methods" and "isa" are used to express the different aspects of the class.
Attributes
has: {
x: {is: ro},
y: {is: rw},
},The first element of the declaration of the Point class is the has-block which defines two attributes of the Point class: x and y. The block x: {is: ro} defines x as being read only. y: {is: rw} defines x as being an read/write attribute. Joose will automatically create a getter getX for x and a getter and setter setY for y. The names of the accessor methods are created using the camelCase conventions. The first letter of the attribute name is thus automatically uppercased.
Methods
methods: {
clear: function () {
this.x = 0;
this.setY(0);
}
}The methods-block defines the method clear() for the Point class. Of course, one could put many more methods in the methods-block. Because y was declared as read/write, we can use the setY method to set the y attribute.
Inheritance
isa: Point,
The isa-clause in the definition of Point3D defines Point3D as being a sub class of Point.
A Method Modifier
after: {
clear: function () {
this.z = 0;
}
}Joose supports so-called method modifiers. after is just one of 5 method modifierst that declare methods with special behavior. The after-modifier defines methods which will be called after methods with the same name which are defined in the super class.
Credits
This cookbook entry is based on Stevan's entry for Moose. Thank you so much!
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