ANN: Iowa 0.9.1 Released

ruby-talk
1

Iowa 0.9.1 has hit Rubyforge.

If you don't know what Iowa is, in a nutshell, it is a framework for
developing web based applications and dynamic web sites. It takes an object
oriented approach, seperates code from layout while still allowing easy
access to the code from the layout, and runs on both Windows and *nix
platforms. Iowa processes run as discrete backend processes, and can be
used with Apache + a mod_ruby handler, WEBrick, or via FCGI or even CGI
interfaces. Iowa handles sessions for you automatically, on the server side
and lets the developer concentrate on simply writing code to make things
work. Since everything is an object, one just uses regular Ruby/object
paradigms to pass information from one part of the application to another,
and creating reusable components is easy.

New for 0.9.1:

* Inline content generation. i.e. an application can generate content like
   images inline, getting a URL back from Iowa that, when accessed, will
   display the generated content without ever requiring that the temporary
   content (images or whatever) be written to a temporary file on disk and
   without requiring one to explicitly setup a seperate service to generate
   the temporary content. i.e. an art gallery application may store the
   images within a database. When a page with art on it is being displayed,
   the code for the page can simply query the image data from the database
   along with the rest of the information on the piece of art. To insert a
   queried image into the content, on the code side just create a method
   that invokes resource_url() with the image information, and it will return
   to your template a URL that will access the resource.
  
* Added a simplistic demo of the above to the webrick demo, and fixed
   a couple very minor bugs in the webrick demo.
  
* Changed the Hash.downcase_keys to a better implementation.

* Improved WEBrick support. It is simpler to use, now.

* Bindings can now be placed in a seperate file from both code and layout.
   To do this, create a file with the same name as the .iwa and .html files,
   but with a .bnd suffix. When used in this way, the <? ?> blocks need
   not be used, though they can be. Comment lines in bindings is also
   now supported. A comment is any line where the first non-whitespace
   character is a #.
  
* The LRUCache can now support age based expiration in addition to the
   strict size based expiration mode. If the class variable @@cacheTTL is
   set for either Application or Session, it will be applied to the session
   cache or to the page cache, respectively. @@cacheTTL is the number of
   seconds to allow something to exist in the cache. Items older than that
   number of seconds will be expired. The hard limit on cache sizes
   expressed by the @@cachedSessions and @@cachedPages variables will
   still apply, as well. That way there is always a hard limit to protect
   against unbounded cache growth. For example, if one set, for Application,
   @@cacheTTL to 1800 and @@cachedSessions to 100, Iowa would allow up to
   100 sessions that were under a half of an hour in age to exist in the
   session cache. If anyone has any suggestions for other/different/better
   cache handling, please let me know.

You can get it at Rubyforge: http://rubyforge.org/projects/iowa
Documentation is online at: http://enigo.com/projects/iowa

I have changed/added documentation to start covering some of the new
features. Please let me know if you have any questions, comments, or
suggestions.

Thanks,

Kirk Haines

2

Kirk Haines wrote:

Iowa 0.9.1 has hit Rubyforge.

Great!

I've again two questions.

1) Is it possible to use Iowa without sessions?

2) I'd like to create an Iowa session whenever the URL /comment/PageName is invoked, where PageName is variable. I'd like to show all comments for "PageName", and the user should be able to add his/her comments, too. My question is, how to create the session with the specific information ("PageName") filled in and then issue the request. Sure, for this kind of application, session are not required at all, but they probably are for Iowa.

Thanks in advance.

Regards,

   Michael

3

1) Is it possible to use Iowa without sessions?

At the current time they are pretty much implicit, even if what one is
doing, like you describe below, isn't an application that uses sessioning.
There's very little performance penalty to the sessioning, though. It just
means that your session gets stuffed into a cache.

2) I'd like to create an Iowa session whenever the URL
/comment/PageName is invoked, where PageName is variable. I'd like
to show all comments for "PageName", and the user should be able to
add his/her comments, too. My question is, how to create the session
with the specific information ("PageName") filled in and then issue
the request. Sure, for this kind of application, session are not
required at all, but they probably are for Iowa.

First, let's make sure I am answering the right question. You want to
receive requests at /comment/FOO, where FOO can be anything. You want to
then invoke some component with the value of FOO passed to it so that it can
query the right set of comments to display, right?

Kirk

···

On Thu, 19 Aug 2004 20:32:38 +0900, Michael Neumann wrote

4

Kirk Haines wrote:

···

On Thu, 19 Aug 2004 20:32:38 +0900, Michael Neumann wrote

2) I'd like to create an Iowa session whenever the URL /comment/PageName is invoked, where PageName is variable. I'd like to show all comments for "PageName", and the user should be able to add his/her comments, too. My question is, how to create the session with the specific information ("PageName") filled in and then issue the request. Sure, for this kind of application, session are not required at all, but they probably are for Iowa.

First, let's make sure I am answering the right question. You want to receive requests at /comment/FOO, where FOO can be anything. You want to then invoke some component with the value of FOO passed to it so that it can query the right set of comments to display, right?

Exactly!

Regards,

   Michael

5

> First, let's make sure I am answering the right question. You want to
> receive requests at /comment/FOO, where FOO can be anything. You want

to

> then invoke some component with the value of FOO passed to it so that it

can

> query the right set of comments to display, right?

Exactly!

Okay. In general, what you want to do is to setup a Main.iwa that is
something like this

class Main < Iowa::Component

  def setup
    comment_parameter = File.basename(session.context.request.request_uri)
    dispatch_page = page_named('YourComponent')
    dispatch_page.comment_parameter = comment_parameter
    dispatch_context = Iowa::Context.new(session.context.request,
session.context.response)
    dispatch_context.sessionID = session.context.sessionID
    dispatch_context.requestID = session.requestCount
    dispatch_page.handleResponse(dispatch_context)
    session.currentPage = dispatch_page.dup
  end
end

What this does is takes the request and pulls the last part off of the
path. It then creates an instance of the component that you actually want
to have handle the current request, and passes that last bit of the path
into a variable in that component. Then is passes the execution along.

This is actually a common enough activity in my code that I really should
provide a simple method for taking care of all of the exposed mechanics
above. I'll make that a part of the next release.

Give me a shout if I can help out further.

Thanks,

Kirk Haines

···

On Fri, 20 Aug 2004 00:31:28 +0900, Michael Neumann wrote