Autoloading objects — Ruby equivalent for PHP5 "__autoload

ruby-talk
1

Does there exist a Ruby equivalent to PHP5 "magic" __autoload method
that spares the developer from detailing a list of "require" statements?
http://us2.php.net/autoload

Or is this something that a homebrewed solution is necessary? Like
catching the exception and testing for file existence, etc.… or is there
a gem/extension featuring this functionality?

···

--
Posted via http://www.ruby-forum.com/.

2

check out module Kernel - RDoc Documentation its close
to what you want.
ActiveSupport is a gem which does autoloading, but it may be specific in the
way it does it.

j`ey
http://www.eachmapinject.com

···

On 7/24/06, Naum T. <naum@azplace.net> wrote:

Does there exist a Ruby equivalent to PHP5 "magic" __autoload method
that spares the developer from detailing a list of "require" statements?
http://us2.php.net/autoload

Or is this something that a homebrewed solution is necessary? Like
catching the exception and testing for file existence, etc.… or is there
a gem/extension featuring this functionality?

--
Posted via http://www.ruby-forum.com/\.

3

Naum T. wrote:

Does there exist a Ruby equivalent to PHP5 "magic" __autoload method that spares the developer from detailing a list of "require" statements?
http://us2.php.net/autoload

Or is this something that a homebrewed solution is necessary? Like catching the exception and testing for file existence, etc.… or is there a gem/extension featuring this functionality?

Sure there is ;D

Kernel#autoload:
http://ruby-doc.org/core/classes/Kernel.html#M002963

and:

Module#autoload:
http://ruby-doc.org/core/classes/Module.html#M001061

lopex

4

Does there exist a Ruby equivalent to PHP5 "magic" __autoload method
that spares the developer from detailing a list of "require" statements?
http://us2.php.net/autoload

Or is this something that a homebrewed solution is necessary? Like
catching the exception and testing for file existence, etc.… or is there
a gem/extension featuring this functionality?

const_missing is a little more like PHP's __autoload function.

The following, for example will attempt to just do: require <object

in the event it can't find the class.

def Object.const_missing name
  require name.to_s.downcase
  const_get(name)
end

I've never used it though, so anyone can feel free to correct me for any gotchas that I'm not aware of.
-Mat

···

On Jul 24, 2006, at 5:58 AM, Naum T. wrote:

5

Naum T. escribió:

Does there exist a Ruby equivalent to PHP5 "magic" __autoload method
that spares the developer from detailing a list of "require" statements?
http://us2.php.net/autoload

Or is this something that a homebrewed solution is necessary? Like
catching the exception and testing for file existence, etc.… or is there
a gem/extension featuring this functionality?

def Object.const_missing elem
  require elem.to_s
end

a = A.new

PS. I would advise *NOT* doing this kind of thing, thou. It can make
your code much harder to debug for other developers.

6

Marcin Mielżyński wrote:

Naum T. wrote:

Does there exist a Ruby equivalent to PHP5 "magic" __autoload method that spares the developer from detailing a list of "require" statements?
PHP: Autoloading Classes - Manual

Or is this something that a homebrewed solution is necessary? Like catching the exception and testing for file existence, etc.… or is there a gem/extension featuring this functionality?

Sure there is ;D

Kernel#autoload:
module Kernel - RDoc Documentation

and:

Module#autoload:
class Module - RDoc Documentation

That's not quite it. You need to call Module.autoload yourself. PHP's autoload is called by the interpreter to perform the inclusion. You could use const_missing to get a similar functionality, though...

def Object.const_missing(name)
   load name.to_lower + ".rb"
end

That's got a few rough edges, though, to put it mildly...

···

--
Alex

7

That's seems to be the ticket.

Knew about ruby autoload, but you have to specify up front each
module/file whereis PHP5, it's (but named "__autoload") a "catch all".

One solution is to glob the directory (where I have my classes stored)
and issue autoload for each result:

# assumes my custom classes begin with upper case
Dir.glob('[A-Z]*.rb').each do |f|
  rsym = f.gsub("[.]rb$", '')
  autoload(:#{rsym}, f)
end

···

const_missing is a little more like PHP's __autoload function.

The following, for example will attempt to just do: require <object
> in the event it can't find the class.

def Object.const_missing name
  require name.to_s.downcase
  const_get(name)
end

I've never used it though, so anyone can feel free to correct me for
any gotchas that I'm not aware of.
-Mat

--
Posted via http://www.ruby-forum.com/\.

8

Naum T. escribió:

Does there exist a Ruby equivalent to PHP5 "magic" __autoload method
that spares the developer from detailing a list of "require" statements?
PHP: Autoloading Classes - Manual

Or is this something that a homebrewed solution is necessary? Like
catching the exception and testing for file existence, etc.… or is there
a gem/extension featuring this functionality?

def Object.const_missing elem
  require elem.to_s
end

a = A.new

PS. I would advise *NOT* doing this kind of thing, thou. It can make
your code much harder to debug for other developers.

you need

def Object.const_missing elem
  require elem.to_s

const_get(elem)

end

To make this work, otherwise the 'A' in A.new becomes the return value of 'require elem.to_s'
-Mat

···

On Jul 25, 2006, at 7:22 AM, Gonzalo Garramuno wrote:

9

I do hope you know that there's a lot of things in Ruby that makes a
developer's debugging life quite hard, but the point is that it's
convenient to have these sort of solutions.

···

On 7/25/06, Gonzalo Garramuno <ggarra@advancedsl.com.ar> wrote:

Naum T. escribió:
> Does there exist a Ruby equivalent to PHP5 "magic" __autoload method
> that spares the developer from detailing a list of "require" statements?
> PHP: Autoloading Classes - Manual
>
> Or is this something that a homebrewed solution is necessary? Like
> catching the exception and testing for file existence, etc.… or is there
> a gem/extension featuring this functionality?
>

def Object.const_missing elem
require elem.to_s
end

a = A.new

PS. I would advise *NOT* doing this kind of thing, thou. It can make
your code much harder to debug for other developers.

--
Matt

10

Mat Schaffer wrote:

const_missing is a little more like PHP's __autoload function.

The following, for example will attempt to just do: require <object
> in the event it can't find the class.

def Object.const_missing name
  require name.to_s.downcase
  const_get(name)
end

Well, th const_missing sollution does work, but only in scripts called
directly in shell by 'ruby' executable. When using it in script called
in browser i get:

[Tue Mar 20 16:56:49 2007] [error] mod_ruby: error in ruby
[Tue Mar 20 16:56:49 2007] [error] mod_ruby:
/home/services/httpd/html/TRON/ruby/index.rb:11: uninitialized constant
#<Module:0xb6a6ea30>::Test (NameError)
[Tue Mar 20 16:56:49 2007] [error] mod_ruby: from
/usr/lib/ruby/1.8/apache/ruby-run.rb:38:in `load'
[Tue Mar 20 16:56:49 2007] [error] mod_ruby: from
/usr/lib/ruby/1.8/apache/ruby-run.rb:38:in `handler'

Got apache 2.2 with mod_ruby configured as follows:

LoadModule ruby_module modules/mod_ruby.so

<IfModule mod_ruby.c>

        AddType text/html .rb

        RubyRequire apache/ruby-run

        <Files *.rb>
                Options +ExecCGI
                SetHandler ruby-object
                RubyHandler Apache::RubyRun.instance
        </Files>

</IfModule>

What i`ve been trying to get is an equivalent of PHP __autoload()
routine working under both shell execution and apache handler. Know any?

···

--
Posted via http://www.ruby-forum.com/\.

11

Alex Young wrote:
<snip>

def Object.const_missing(name)
  load name.to_lower + ".rb"
end

That's got a few rough edges, though, to put it mildly...

I mean, besides the fact that it won't work, unlike Mat's. Should have tested that one...

···

--
Alex

12

ri Kernel.autoload

···

On 3/20/07, Piotr Biedruna <p.biedruna@gmail.com> wrote:

Mat Schaffer wrote:

> const_missing is a little more like PHP's __autoload function.
>
> The following, for example will attempt to just do: require <object
> > in the event it can't find the class.
>
> def Object.const_missing name
> require name.to_s.downcase
> const_get(name)
> end

Well, th const_missing sollution does work, but only in scripts called
directly in shell by 'ruby' executable. When using it in script called
in browser i get:

[Tue Mar 20 16:56:49 2007] [error] mod_ruby: error in ruby
[Tue Mar 20 16:56:49 2007] [error] mod_ruby:
/home/services/httpd/html/TRON/ruby/index.rb:11: uninitialized constant
#<Module:0xb6a6ea30>::Test (NameError)
[Tue Mar 20 16:56:49 2007] [error] mod_ruby: from
/usr/lib/ruby/1.8/apache/ruby-run.rb:38:in `load'
[Tue Mar 20 16:56:49 2007] [error] mod_ruby: from
/usr/lib/ruby/1.8/apache/ruby-run.rb:38:in `handler'

Got apache 2.2 with mod_ruby configured as follows:

LoadModule ruby_module modules/mod_ruby.so

<IfModule mod_ruby.c>

        AddType text/html .rb

        RubyRequire apache/ruby-run

        <Files *.rb>
                Options +ExecCGI
                SetHandler ruby-object
                RubyHandler Apache::RubyRun.instance
        </Files>

</IfModule>

What i`ve been trying to get is an equivalent of PHP __autoload()
routine working under both shell execution and apache handler. Know any?

--
Posted via http://www.ruby-forum.com/\.

--
Chris Carter
concentrationstudios.com
brynmawrcs.com

13

You would probably want to use some metaprogramming to define
const_missing recursively on currently defined constants, and then
it's pretty much the same as PHP's __autoload().

···

On 7/24/06, Alex Young <alex@blackkettle.org> wrote:

Alex Young wrote:
<snip>
> def Object.const_missing(name)
> load name.to_lower + ".rb"
> end
>
> That's got a few rough edges, though, to put it mildly...
>
I mean, besides the fact that it won't work, unlike Mat's. Should have
tested that one...

--
Alex

--
Matt