Using Initializers

Rails
1

I have a template that I use for creating Rails web sites. There is
some limited template configuration data which I store in a global
hash variable. This hash variable is initialized in the applications
controller. It all works just fine. However, I think that I need to
clean up my act a bit. The applications controller is probably not
the best place to initialize the global variable. I tried to do it
with an assignment statement in an initializer file; but, it didn’t
work (i.e., view templates didn’t see it for some reason). Can
someone please tell me why that is and what might work? Also, I fully
recognize that global variables are to be avoided (but it sure works
fine :slight_smile: ). Does anyone have a suggestion as to what I might use to
replace the global variable?

Thanks for any input.

     ... doug
2

Interesting. The procedure that you describe is much different than
what I expected. So, I guess that I’m not surprised that what I did
failed to work. Thanks. I’ll give it a try.

      ... doug
3

I have another example that I have used for a while…

/config/settings.yml
all: &all_environment_settings
constant_for_all: somethinf

development: &non_production_settings
<<: *all_environment_settings
something_different_for_dev: dev stuff

Then you can load this file in a initializer:

/initializers/settings.rb
SETTINGS = YAML.load_file("#{RAILS_ROOT}/config/settings.yml")
[RAILS_ENV].symbolize_keys

Now you can call this through SETTINGS[:constant_for_all]

Both methods will work but if you have requirements for the constants
to change between environments then this would be better…

4

Thanks to all who responded to my inquiry.

This appears to be a rather basic issue that, for whatever reason,
doesn’t seem to get much attention.

I’ve reviewed everything. My conclusion is that, for my purposes, the
very basic first approach of just declaring the single needed global
constant in a file added to the initializers directory is enough to
meet my needs.

Again, thanks to all for the input.

   ... doug
5

Hi Doug J.

 You can create a file like global_constants.rb in initializers

folder and declare all the global there …
Or
Inside this same file create like

module GlobalConstant
Constantname = value
end

GlobalConstant.freeze

And access it like GlobalConstant::Constantname

    The second one I have not tried.But thinking that it will work

Sijo K George

6

Doug J. wrote:

Thanks to all who responded to my inquiry.

This appears to be a rather basic issue that, for whatever reason,
doesn’t seem to get much attention.

I’ve reviewed everything. My conclusion is that, for my purposes, the
very basic first approach of just declaring the single needed global
constant in a file added to the initializers directory is enough to
meet my needs.

I hope you don’t mean “global” as in “Ruby global with a dollar sign”.
If so, that’s asking for trouble. Please see Railscast #85 for a simple
way of doing this right.

Again, thanks to all for the input.

   ... doug

Best,

Marnen Laibow-Koser
http://www.marnen.org
[email protected]