SeeSaw's blog: Category Tips & Tricks

File Encoding Conversion

Paolo — Wed, 27 Feb 2008 12:47:00 -0600

This morning I struggled a bit to find a decent encoding converter for osx… from time to time I get stuck on encoding issues so I wanted to have something ‘friendly’ to handle this kind of problems…

I found Cyclone based on Apple Text Encoding Converter (look for TEC) but it kept failing in some strange ways (It gave me weird messages about converters creation). After googling for a while I gave up. It seems there are no good-free-GUI alternatives on the net…

Sometimes the solution is closer than you think and the good old iconv rescued me in a snap:

[paolo@fingus]$ iconv -f UTF-16 -t UTF-8 utf16_file.txt > utf8_file.txt

you can list the available encodings with:

[paolo@fingus]$ iconv -l

The cool part is you can use it in conjunction with TextMate’s Filter Through Command feature thus enabling in-editor lightning-fast conversions.

The only missing part was discovering the original file’s encoding, in order to pass iconv the correct -f option. The not-so-reliable way I used was to open the file with Firefox and inspect the encoding using the View -> Character Encoding menu item.

That’s it, problem solved. If you know better ways to do this… let me know!

SpringFramework meeting report

Paolo — Fri, 20 Jul 2007 09:35:00 -0500

Last weekend I had the opportunity to give a speech at the Spring Framework meeting in Cagliari.

My speech was about new features I and Michele added to the Java Parancoe framework, fixtures and plugins (the Parancoe website hasn’t been migrated from the old java.net one yet so be patient).

I think Parancoe is now the only Java framework that supports Yaml fixtures as RubyOnRails does, and that’s pretty cool because we can now have solid functional tests and we can share test data between the test and development environment.

The pluggability of Parancoe it’s a cool feature too, we can now extend the framework without cluttering the core… You just define a fragment of a web application and you can put its jar file in the classpath, thus enabling the plugin. Plugins can autocreate tables, populate them with yaml fixtures, expose DAOs, business services, controllers and can interact with the application lifecycle (filters/interceptors or context listeners).

An example? the Italy Plugin. If you drop the parancoe-plugin-italy.jar in your classpath your application will be blessed with 4 new auto-created tables: Comuni, Provincie, Regioni, Procure. Those tables get auto-populated with real data when your app starts, and you’ll automatically have the spring managed DAOs you need to interact with these tables exposed in your spring context. Having these kind of modules simplify and quickens the development of your Java applications.

Many other plugins are on the way, World Plugin and Security Plugin on top of them.

PS: If you’re interested in the Parancoe framework, drop me a line or put a comment here.

Getting back to the SpringMeeting. I’ll point you to a few resources:

Our friend Lucio Benfante gave a speech on Parancoe too and wrote a good article about the event.
There is a report of the trip on the JUG Padova website.
You can download the Parancoe source code with examples and plugins at http://code.google.com/p/parancoe.
You can ask more about Parancoe on the JUG Padova mailing list.
Pictures of the event: mine, Lucio & Massimiliano.

That’s it for now…

Todo list and next action with GMail

Paolo — Mon, 07 May 2007 13:49:00 -0500

I’m kind of getting into GTD during this period, but I find myself very lazy at organizing my stuff. I find it pretty difficult to stick with a specific tool for managing my todo list. Basically I don’t want to use yet another tool, and I feel I would only need a quick and dirty solution to track my todo items and my very next actions.

After trying a bunch of tools I came out with this simple solution: I store todo items in my GMail account. Nothing new or very smart, but it works pretty well. Let’s see how to do it:

create a new contact named todo whose email is your_account_name+todo@gmail.com (eg: paolo.dona+todo@gmail.com)
create a label todo
create a filter that matches to:(your_account_name+todo@gmail.com) and do this: Skip Inbox, Apply label “todo”.

Once you’ve completed these little steps, you can start using your brand new todo-list manager. Oh well, I haven’t told you how to use it yet… so:

How to add a todo item?

Send an email to your todo contact (It’s just yourself!) and it will be automatically archived, this way it doesn’t clutter your inbox.

How to see your pending items?

Click on your todo label inside the left Labels box.

How to mark a todo item as finished?

Delete it. (YOU said it’s finished :-P)

How to mark a todo item as a “next action”?

Star it.

How to see you next actions?

Run this search: label:todo is:starred. Actually I’m using the saved searches greasemonkey script to save this query and have it available as a next actions link just under my Labels box.

Conclusions

This approach is very simple but I see a few key benefits in it:

Gmail is always open in my browser, I don’t need to keep another window or tab open just to see my todos.
I can add filters that automatically populate my todo list. For example my Google Calendar reminders get labelled as todo so I can see them in my todo list. The same happens with Basecamp or Highrise todo item/task notifications.
You can play with labels and easily let todo items belong to projects, locations etc (GTD style).
You can reply to your todo items to add comments or further details to the activity they refer to.

Feel free to share your ideas on this.

DNS shortcuts by OpenDNS

Paolo — Mon, 23 Apr 2007 14:34:00 -0500

Today I discovered a nice feature of OpenDNS: if you register an account in opendns.com you will be able to map URL shortucts to web sites. They will be recognized automatically when you type them in your preferred web browser. For example I mapped “mail” to http://mail.seesaw.it, and this allow me to open my webmail page just typing “mail” in my firefox navigation bar. This could be even faster than using a bookmark if you’re already using keyboard shortcuts in your browser.

A sample: I often need to open the SeeSaw’s Basecamp account (http://seesaw.seework.com). I registered an OpenDNS shortcut named “bc” that points to that URL and now I can do something like:

open firefox (ALT+SPACE, type “f” then ENTER) using Launchy.
open basecamp in firefox (CTRL+L, type “bc” then ENTER)

Pretty cool! Of course you need to use OpenDNS in order to make that work.. Happy shortcutting!

Fixing KRJS

Paolo — Fri, 02 Mar 2007 13:19:00 -0600

A few days ago I discovered the great KRJS Plugin for RubyOnRails. It basically lets you write callbacks methods in your controller and binds them to ajax calls based on a naming convention.

You can write something like this:

def on_account_login_blur
   render :update do |page|
      page.insert_html :after, 'form', '...'
   end
end

that is automatically AJAX-invoked at the onBlur event in the account_login input field.

KRJS inserts the onBlur event in your field if it finds a matching method in the current controller.

The only issue with this plugin is that it redefines TagHelper’s tag and content_tag methods. So, if you’re using something like:

ActionView::Base.field_error_proc = Proc.new do |html, instance|
  # customization of your error messages here
end

...you’re losing all your error handling goodness. I struggled a bit with this and end up rewiting KRJS to use the rails alias_method_chain over the original tag and content_tag methods. While doing this I also tried to clean up the code a bit.

So if you’re interested you can download my version here,. Don’t be afraid to report any issue, it’s alpha code …

Good AJAXing

Auto-Completion in Irb

Michele — Tue, 17 Oct 2006 15:12:00 -0500

A fast & effective way for having auto-completion in irb (with some limitation) via web on rails

Getting MIME type from a file

Michele — Sat, 09 Sep 2006 22:56:00 -0500

It’s pretty simple: just grab activation framework from the web and type:

import javax.activation.MimetypesFileTypeMap;
import java.io.File;
...
File file = new File("WhoAmI.jpg");

System.out.println("MIME type of " +
  file.getName() + " is " +
  new MimetypesFileTypeMap().getContentType(file)
);

The expected output is:

MIME type of WhoAmI.jpg is image/jpeg

simple and effective, isn’t it?

UPDATE: If you want to detect types other than simple images you should integrate the activation framework default list as stated in the javadoc . For example detection of a zip archive can be done by adding this:

MimetypesFileTypeMap mt = new MimetypesFileTypeMap();
mt.addMimeTypes("application/x-zip zip ZIP");

The easiest way to add tabbed navigation to your Rails app!

Paolo — Sun, 23 Jul 2006 20:09:00 -0500

UPDATE Feb 01, 2007: the Tabnav has been updated in order to work wit Rails 1.2, read this post fom more info.

Hi guys, during our development efforts we needed tabbed navigations. Well, after struggling with the acts_as_wizard plugin (you can find it in the toolbox) we decided to implement yet another rails plugin, and we think this time it’s even easier to use and someway plain cool.

Tabnav it’s so far the easiest way to build tabbed navigation like this:

The Tabnav Rails plugin provides nice tabbed navigation out of the box

All this magic it’s done by this fragment of code put inside my layout:

<%= start_tabnav :main %>
<%= @content_for_layout %>
<%= end_tabnav %>

Sounds cool? keep reading…

Where does the start_tabnav gets informations for tabs rendering? The :main Symbol let the start_tabnav method know to look for a special MainTabnav class where all the magic happens, so in my model directory I’ve got a main_tabnav.rb file containing something like:

class MainTabnav < Tabnav::Base       
  add_tab do 
    named 'Dashboard'
    titled 'Wooooow! what a wonderful tabbed navigation!'
    links_to :controller => 'dashboard'
  end

  add_tab do 
    named 'Users'
    links_to :controller => 'users'
  end 

  add_tab do 
    named 'Companies'
    links_to :controller => 'companies'
    highlights_on :controller => 'dashboard', :action => 'statistics'
  end 

  add_tab do 
    named 'Admin'
    links_to :controller => 'companies'
    show_if "params[:admin] == true"
  end      
end

This way you can manage your tabs in a view-indipendent manner. The MainTabnav class should be pretty self-explanatory… but let me point out a few nice features:

The titled method gives your tabs a html ‘title’ attribute so you can have tooltips over your tab link.
The links_to method creates the tab’s link. You can use the same options as the usual ActionView’s url_for. The tab will be automatically highlighted (with the help of a CSS class) if the page you’re viewing matches the links_to options. So if you’re linking to :controller => ‘dashboard’, you can be sure every dashboard’s action will keep the tab highlighted. If you’re linking to :controller => ‘dashboard’, :action => ‘index’ only the index action will highlight it.
You can add more highlighting rules using the highligths_on method. This could be useful if you have more than one controller that should highlight the same tab (eg: think about an estimate wizard involving multliple controllers, keeping an ‘estimates’ tab highlighted).
You can conditionally choose to show or not show a tab given a certain condition with the show_if method. The string parameter given will be evaluated in the view context, so you can show admin pages tabs only to administrators and so on.

It’s cool! Tell me how to use it!

Install it from your rails base directory with this: ruby script/plugin install svn://svn.seesaw.it/tabnav/tags/0.1

And generate how many tabbed navigations you like with:

ruby script/generate tabnav Main

Of course you can substitute ‘Main’ with the desired prefix of your tabnav class.

Then configure your Tabnav model as you desire and include a start_tabnav/end_tabnav statement in your layout or view files.

Can I customize the generated HTML/CSS?

The tabnav generator will create a partial file inside your view/tabnav directory. There you can customize the html and the inline CSS used by your tabnav. You can move the inline CSS to you stylesheet file too.

Can I nest navigations?

Yes of course, with tabnav you can easily do something like:

You can easily nest tabnavs. They rely on their own model, partial and CSS stylesheet.

Another little trick…

Last but not least you can have tabbed navigations without having a whole ‘containing box’ using just a:

<%= tabnav :main %>

This way you can do stuff like:

You can have just navigation tabs without the whole box attached under them

That’s it right now guys. Hope you find it useful! Don’t forget we need feedback, so feel free to comment on this post or send us a private email.

If you want to keep in touch with further developments you can even subscribe to our rss feed.

This plugin is part of the SeeSaw’s toolbox.

having trouble downloading the plugin? You can install it without subversion:

In vendor/plugins, create directory tabnav. In that directory download end extract this!

Update: Due to a server migration, we’ve moved our repositories to a new location… see this for more info.

acts_as_wizard refactored!

Paolo — Mon, 17 Jul 2006 23:58:00 -0500

Our acts_as_wizard plugin needed improvements to address a few needs of an application we’re currently working on. I promised improvements to a bunch of early adopters too so finally I took my time and have done this dirty work.

If you don’t know acts_as_wizard yet, you just need to know it’s a rails plugin to help you build clean and simple web wizards.

You can find acts_as_wizard articles, installation instructions, tutorials and previous posts in the SeeSaw’s toolbox.

A Wizard can be simply defined this way:

class CreateCatAndDogWizard < Wizard::Base     
    add_step do 
      named 'Insert your cat'
      controlled_by :cats
      enable_actions :new, :create
      add_rewrite({:action => 'list'}, 
                  {:controller => 'dogs', :action => 'new'})
    end 

    add_step do
      named 'Insert your dog'
      controlled_by :dogs
      enable_actions :new, :create
      add_rewrite({:action => 'list'}, 
                  {:controller => 'main', :action => 'finished'})
    end 

    add_step do 
      named 'Finished!'
      controlled_by :main
      enable_actions :finished 
    end     
end

The main areas our refactoring focused on are:

get rid of every controller contamination: we wanted controllers to be totally unaware of being part of a wizard.
multi wizard support: the same controller must be able to take part of different wizards.
general code cleanup: well, we just were ashamed of some dirty code..

If you’ve never uses acts_as_wizard, you don’t need to read what follows, just remember it has gotten better :)

If you were an early adopter instead, keep reading an I’ll show you what technically has changed…

Now almost everything is configured in the Wizard class.

You must delete acts_as_wizard and on_wizard_rewrite statements from your controllers.

The steps definition inside your Wizard class has changed and now supports the add_rewrite method, this way you can substitute every controller rewriting with a step’s add_rewrite call.

The acts_as_wizard statement has been substituted by the controlled_by statement inside your step.

Controllers are no more tied to a single wizard. The controlled_by method takes a symbol as parameter, so different wizards can have steps pointing to the same controller.

You need just to modify your steps this way:

add_step do
  named 'Insert your cat'
  controlled_by :cats
  enable_actions :new, :create
  add_rewrite({:action => 'list'}, 
              {:controller => 'dogs', :action => 'new'})
end

The controlled_by statement will inject necessary objects in your controller.

To start a wizard you need to pass a parameter with the name of your wizard underscored:

<%= link_to 'create a cat and a dog with a wizard',
               :controller => 'cats',
               :action => 'new',
               :wizard => 'create_cat_and_dog'%>

The :wizard=>true form is no longer valid

You MUST require your wizard class in your application.rb.

This is needed because rails usually requires files only when needed, but we need to inject wizard objects in involved controllers at startup.

PS: require after the ApplicationController declaration.

class ApplicationController < ActionController::Base
end
require 'create_cat_and_dog_wizard'

That’s it for now. A further development could be the creation of view helpers to easily start a wizard or go to the prev/next action.

Let us know if you got in trouble with it or got ideas to share.

Always feel free to drop us an email at staff@seesaw.it and subscribe to our feed if you wanna stay tuned on aaw evolution.

You can find more info about the acts_as_wizard plugin in the toolbox.

Choose the right killer

Michele — Fri, 16 Jun 2006 18:00:00 -0500

Sometimes happens that a server process become too lazy, mutate himself into a fat memory eater, hang or simply don’t want to die.

If you (like me) are about to say “Is this a problem? kill -9 is the right remedy!” it’s time to read why this way should be used only as in-case-of-death resource.