bob-gray/solv

/* istanbul ignore if */
if (typeof define !== "function") {
    var define = require("amdefine")(module);
}

define(function (require) {
    "use strict";

    require("./base");
    require("./emitter");
    
    var Observable,
        changeEvent,
        propertyChangeEvent,
        meta = require("../meta"),
        createClass = require("../class/create");

    meta.setRequire(require);

    Observable = createClass(
        meta({
            "name": "Observable",
            "description": "General observable base class",
            "mixins": [
                "./base",
                "./emitter"
            ]
        })
    );
    
    Observable.method(
        meta({
            "name": "set",
            "description": "Sets the value of a property",
            "arguments": [{
                "name": "property",
                "type": "string"
            }, {
                "name": "value",
                "type": "any"
            }]
        }),
        set
    );
    
    Observable.method(
        meta({
            "name": "get",
            "description": "Gets the value of a property",
            "arguments": [{
                "name": "property",
                "type": "string"
            }]
        }),
        get
    );
    
    changeEvent = meta({
        "name": "change",
        "when": "A property is set to a new value",
        "params": [{
            "name": "property",
            "type": "string"
        }, {
            "name": "oldValue",
            "type": "any"
        }, {
            "name": "newValue",
            "type": "any"
        }]
    });
    
    propertyChangeEvent = meta({
        "name": "<property>-change",
        "when": "A property is set to a new value",
        "params": [{
            "name": "property",
            "type": "string"
        }, {
            "name": "oldValue",
            "type": "any"
        }, {
            "name": "newValue",
            "type": "any"
        }]
    });
    
    function set (property, newValue) {
        var oldValue = this[property];
        
        if (newValue !== oldValue) {
            this[property] = newValue;
            this.invoke(triggerChange, property, oldValue, newValue);
        }
    }

    function triggerChange (property, oldValue, newValue) {
        propertyChangeEvent.name = property +"-change";
        this.trigger(propertyChangeEvent, property, oldValue, newValue);
        this.trigger(changeEvent, property, oldValue, newValue);
    }
    
    function get (property) {
        return this[property];
    }
    
    return Observable;
});