john-n-smith/mvcobject-js

An implementation of the KVO pattern, inspired by Google Maps API v3 MVCObject class

mvcobject-js's Issues

Unbinding a non-bound property throws the wrong error.

var abc = new MVCObject;
abc.set('testing', 'hi');
abc.unbind('testing');

> Uncaught TypeError: Cannot use 'in' operator to search for '__my_index' in 
null
from line 235 of source.

I would personally expect unbinding an unbound property to do nothing. The code 
appears to want to throw a different error: '"' + key + '" is not a bound 
property.' but the code never gets there.

The key from line 235 is this clause:

'__my_index' in this[key]

...where this[key] is apparently null. Adding a check for this[key] resolves 
the issue.

Again, I would prefer (and have modified the source locally) to not throw an 
error at all in this scenario.

Original issue reported on code.google.com by [email protected] on 3 Dec 2012 at 11:27

What is the test at the start of .set() supposed to do?

I added a comment to line 193 indicating I think there is mistake:

http://code.google.com/p/mvcobject-js/source/browse/trunk/MVCObject.js#193

The comment appears to indicate that one isn't allowed to set a property that 
isn't already set, but then how does one set a value the first time?

Original issue reported on code.google.com by [email protected] on 16 Sep 2012 at 4:23

Clearing an observer by setting it to null throws an error next time the observed property changes.

What steps will reproduce the problem?
var abc = new MVCObject;
abc.property = null;
abc.property_changed = function() { console.log('triggered'); };
abc.set('property', 'value1');
> triggered
abc.property_changed = null;
abc.set('property', 'value2');
> "TypeError: Property 'property_changed' of object #<MVCObject> is not a 
function" from line ~225

I expect no error when my callback is null. Instead I get an error that 
basically says the code tried to run "null".

Using latest version 0.21. By replacing the following line:

if(key + '_changed' in this) this[key + '_changed']();

with this:

if(typeof this[key + '_changed'] === 'function') this[key + '_changed']();

I was able to fix the error. Also verified that an actual observer function 
there will run.

Cheers,
Dave

Original issue reported on code.google.com by [email protected] on 26 Jan 2013 at 1:07

Sample Code is raising foo_changed callback not found exceptions

What steps will reproduce the problem?
1. only execute sample code
2.
3.

What is the expected output? What do you see instead?
Uncaught TypeError: Property 'foo_changed' of object #<MVCObject> is not a 
function 

What version of the product are you using? On what operating system?
lastest version MVCObject-source-0.20.js

Please provide any additional information below.
need to modify code in MVCObject.prototype.set function


for(var i in this[key].__shared_object.__observers)
{
    if(this[key].__shared_object.__observers[i] === null) continue;

    //ADDED 2012.10.10 addition code Trigger the observer's observer's callbacks
    if( this[key].__shared_object.__observers[i].key + '_changed' in this[key].__shared_object.__observers[i].obj)
                this[key].__shared_object.__observers[i].obj[this[key].__shared_object.__observers[i].key + '_changed']();
}

Original issue reported on code.google.com by [email protected] on 10 Oct 2012 at 7:29

Attachments:

• MVCObject-source-0.20.js

Setting a value which is not currently on the object throws an error. (Ditto unbind, et al.)

What steps will reproduce the problem?
var abc = new MVCObject();
abc.set('newProperty', 'anything')
> Cannot set value for undefined property "newProperty".

There's no reason that this error needs to be thrown. If I remove this line 
(line 193) entirely, the object behaves as expected – my value gets set 
(down on line 222), and line 225 calls my callback (unless it's null - see 
issue 4).

We've discussed elsewhere that this (awesome) library throws a lot of errors. 
In my experience this is a seriously annoying design flaw. Unbinding a property 
that isn't bound throws an error on line 296, but the result of an unbind 
operation - having something that isn't bound - can be achieved by simply 
returning.

Original issue reported on code.google.com by [email protected] on 26 Jan 2013 at 1:29