Neewby question: how to monitor a variable value

Ruby
1

Hello All,

I remember reading in a book that we could very easily monitor the
value of a variable and have for instance an alert message displayed
each time this variable s modified. I do not manage to find how to do
this anymore.
Would you have any clues ?

Thanks a lot,
Luc

2

On 20/10/06, Luc J. [email protected] wrote:

Hello All,

I remember reading in a book that we could very easily monitor the
value of a variable and have for instance an alert message displayed
each time this variable s modified. I do not manage to find how to do
this anymore.
Would you have any clues ?

Thanks a lot,
Luc

Sounds like you need the observer design pattern:
http://wiki.rubygarden.org/Ruby/page/show/ObserverPattern

Farrel

3

Luc J. wrote:

I remember reading in a book that we could very easily monitor the
value of a variable and have for instance an alert message displayed
each time this variable s modified. I do not manage to find how to do
this anymore.

While I’m sure many other similar libraries exist, I’d like to offer up
my own EventTarget library. Instead of being tied to a single event
like the Observable pattern, you can register different callbacks for
different types of actions that occur.

http://phrogz.net/RubyLibs/rdoc/files/EventTarget_rb.html

One of these days I’ll get around to learning how to gem up my libs.
Until then, you can download the source code from the link on that page.

4

Thanks a lot gavin,
I will also give it a try.

Luc

5

One of these days I’ll get around to learning how to gem up my libs.
Until then, you can download the source code from the link on that page.

I just got back from reading this on Ruby Inside and though I’d give
you a heads up:

http://www.rubyinside.com/generate-your-own-ruby-gems-more-easily-268.html

Charles

6

Thanks a lot Farrel,
This is exactly what I needed !!!
Luc

7

Luc J. wrote:

Hello All,

I remember reading in a book that we could very easily monitor the
value of a variable and have for instance an alert message displayed
each time this variable s modified. I do not manage to find how to do
this anymore.
Would you have any clues ?

See also http://raa.ruby-lang.org/project/observable. (And see the
example in my post a few minutes ago on the thread “[ANN] Dependency
1.0.0”.)