Enum.js

Simple Enumerable object in javascript.

Usage

Creating custom Enum

Enum.extend function expect two parameters:

• first is a static properties aka Enum constants,
• second is a custom prototype methods.

var HTTPCodeEnum = Enum.extend({
    CONTINUE:         "100",
    OK:               "200",
    MULTIPLE_CHOISES: "300",
    BAD_REQUEST:      "400",
    INTERNAL_ERROR:   "500"
});

You can also pass in first object:

• static functions, that will can be accessed like MyEnum.myFunction()
• static objects,
• static values, needed for internal usage. To prevent parsing them as Enum constant, add double underscore as prefix, like: __myInternalValue

Enum throws error in some usual cases. So there is an ability to use custom Errors for your custom Enums, to catch them upper and check with instanceOf function:

var HTTPCodeEnum = Enum.extend({
    ... // constants

    __error: MyOwnError // reference to your Error constructor
});

If __error does not present in first parameter object, then Enum will use its own EnumError constructor. Anyway, u can always get the reference to the Error function via Enum.__error

Simple usage

function ajaxCallback(data) {
    if (data.code == HTTPCodeEnum.OK) {
        // ...
    }
}

Enum usage:

function ajaxCallback(data) {

    // Throws a EnumError if catch non existing code
    var status = new HTTPCodeEnum(data.code);

    // Returns mapped message
    // getMessage must be implemented in HTTPCodeEnum.prototype
    console.log(status.getMessage());
}

// Exceptions handling

function indexController() {
    try {
        var request = $.ajax(...).done(ajaxCallback);
    } catch(e) {
        if (e instanceof HTTPCodeEnum.__error) {
            console.log('Catched non existing HTTP code!', e.message);
        }
    }
}