How To Get Properties Of The Object Subjected To Event Using Fabric.js?

Using Fabric.js 1.1.6, I have the following: var rect = new fabric.Rect({}); rect.on('moving', function(obj) { // I want to retrieve and set properties from the // object r

Solution 1:

"Is it possible to retrieve and modify the rect properties from inside the function called by the event?"

Not only it is possible but it is very simple ;) You should read about closures in JavaScript.

For question #1

var rect = new fabric.Rect({});
rect.on('moving', function(obj) {
    rect.someProperty = 'test';
});

For question #2

functionSomeClass() {
    var rect = this.rect = new fabric.Rect({});

    this.rect.on('moving', function(obj) {
        // here, this.rect is undefined
        rect.someProperty;
    });
}