GravityBlast » Ruby

web-app-theme 0.6.1 for rails 3

Andrea Franz — Mon, 27 Sep 2010 23:18:18 +0000

The new version of web-app-theme finally supports Rails 3. Check out the repository on github. It also supports Haml template generation using html2haml, like devise does.

UPDATE: the version 0.6.2 fixes a bug in the Haml generation when you use form_for blocks.

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Ruby library for the musiXmatch API

Andrea Franz — Mon, 20 Sep 2010 00:30:22 +0000

If you want to search for lyrics and tracks with Ruby using the musiXmatch API, check out my repository at http://github.com/pilu/musix_match

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Flex functional testing with FunFx and Cucumber

Andrea Franz — Thu, 20 Aug 2009 13:11:56 +0000

Cucumber is a great tool I usually use for BDD in my ruby projects, but yesterday I tried it with Flex, and it was very enjoyable. Here a little example on how to test Flex applications with Cucumber.

First of all you need ruby, then you need to install the following gems:

sudo gem install rspec cucumber watir safariwatir funfx

(I used the following codes on mac os x, with ruby 1.8.6, safari 4.0.3 and funx 0.2.2)

After that open Flex Builder and create a new project called CucumberExample and use the following code for your main mxml file:

xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
	<mx:Number id="index">0mx:Number>
	<mx:VBox width="300" height="200" backgroundColor="white">
		<mx:HBox width="100%" height="30">			
			<mx:Button id="buttonDecrement" label="-" width="100%" />
			<mx:Button id="buttonIncrement" label="+" width="100%" />
		mx:HBox>
		<mx:HBox width="100%" height="100%" verticalAlign="middle" horizontalAlign="center">
			<mx:Label id="myLabel" text="{index}"/>			
		mx:HBox>
	mx:VBox>
mx:Application>

As you can see, we have a number, 2 buttons and a label. Now create a directory called features inside your flex project folder and create the first Cucumber feature file, called counter:

CucumberExample/features/counter.feature:

Feature: Counter
  In order to count something
  As a flex rock star
  I want to use my great flex app
 
  Scenario: Increment index
    Given I open my flex app
    And I click the increment button
    Then the label text should be "1"
    When I click the decrement button
    Then the label text should be "0"
    When I click the decrement button
    Then the label text should be "-1"

It’s a test written in pure plain text.

In the features folder create another folder called step_definitions with a blank file called counter_steps.rb, we’ll use it later.

Now open the console, go the to flex project root and run your test:

cd /path/to/CucumberExample
cucumber features

You should see something like this:

...
1 scenario (1 undefined)
7 steps (7 undefined)
0m0.002s

You can implement step definitions for undefined steps with these snippets:

Given /^I open my flex app$/ do
  pending
end
 
Given /^I click the increment button$/ do
  pending
end
 
Then /^the label text should be "([^\"]*)"$/ do |arg1|
  pending
end
 
When /^I click the decrement button$/ do
  pending
end

Before implementing the steps above, we need to add the funfx component to our library.

Download the latest swc file from rubyforge and place it in your CucumberExample/libs folder (I used the version 0.2.2).

Duplicate the bin-debug folder and rename it to test (you have a bin-debug folder after the first time you run the CucumberExample from FlexBuilder).

Inside the test directory create a file called test_server.rb with the following content:

require 'webrick'
 
server = WEBrick::HTTPServer.new :Port => 9852, :DocumentRoot => File.dirname(__FILE__)
trap("INT"){ server.shutdown }
server.start

Now you need a compiled version of your project that includes funfx.We’ll use it just for testing:

build_test.sh

#!/bin/sh
FLEX_SDK_HOME="/Applications/Adobe Flex Builder 3/sdks/3.2.0"
"$FLEX_SDK_HOME/bin/mxmlc" -verbose-stacktraces -include-libraries ./libs/funfx-0.2.2.swc "$FLEX_SDK_HOME/frameworks/libs/automation.swc" "$FLEX_SDK_HOME/frameworks/libs/automation_dmv.swc"  "$FLEX_SDK_HOME/frameworks/libs/automation_agent.swc" -output ./test/CucumberExample.swf -- ./src/CucumberExample.mxml

Run test compile_test.sh

chmod 755 ./build_test.sh
./build_test.sh

Now open another terminal window and start the test server:

cd /path/to/CucumberExample/test
ruby test_server.rb

Open http://localhost:9852/CucumberExample.html with your browser and you should see your flex app.

Now you can come back to your features and implement the step we leave before. Here my implementation:

CucumberExample/features/step_definitions/counter_steps.rb

Given /^I open my flex app$/ do
  open_flex_app
end
 
Given /^I click the (increment|decrement) button$/ do |button|  
  click_button("button#{button.capitalize}")  
end
 
Then /^the label text should be "([^\"]*)"$/ do |text|
  label_text.should == text  
end

open_flex_app, click_button and label_text are methods defined in my env.rb file.

CucumberExample/features/support/env.rb

require "rubygems"
require 'funfx/browser/safariwatir'
 
module FlexWorld
  def open_flex_app
    @browser.goto("http://localhost:9852/CucumberExample.html")
  end
 
  def click_button(button_id)
    @flex_app.button(:id => button_id).click
  end
 
  def label_text
    @flex_app.label(:id => "myLabel").text
  end
end
 
Before do
  @browser  = Watir::Safari.new
  @flex_app = @browser.flex_app("CucumberExample", "CucumberExample")  
end
 
After do
  @browser.close
end
 
World(FlexWorld)

Now you are ready to run your tests. Start the test_server and then the features. You should have an error:

Then the label text should be "1"  # features/step_definitions/counter_steps.rb:9
      expected: "1",
           got: "0" (using ==)

This because we didn’t implement the functionality yet in our flex app. So, change the mxml file with the following:

xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
	<mx:Number id="index">0mx:Number>
	<mx:VBox width="300" height="200" backgroundColor="white">
		<mx:HBox width="100%" height="30">			
			<mx:Button id="buttonDecrement" label="-" width="100%" click="index--" />
			<mx:Button id="buttonIncrement" label="+" width="100%" click="index++" />
		mx:HBox>
		<mx:HBox width="100%" height="100%" verticalAlign="middle" horizontalAlign="center">
			<mx:Label id="myLabel" text="{index}"/>			
		mx:HBox>
	mx:VBox>
mx:Application>

It’s the same code but I added the click action to the increment and decrement buttons. Now compile the new code and run the features again:

./build_test.sh
cucumber features

You shoiuld have the following output, with all the seven steps passed:

Feature: Counter
  In order to count something
  As a flex rock star
  I want to use my great flex app
 
  Scenario: Increment index            # features/counter.feature:6
    Given I open my flex app           # features/step_definitions/counter_steps.rb:1
    And I click the increment button   # features/step_definitions/counter_steps.rb:5
    Then the label text should be "1"  # features/step_definitions/counter_steps.rb:9
    When I click the decrement button  # features/step_definitions/counter_steps.rb:5
    Then the label text should be "0"  # features/step_definitions/counter_steps.rb:9
    When I click the decrement button  # features/step_definitions/counter_steps.rb:5
    Then the label text should be "-1" # features/step_definitions/counter_steps.rb:9
 
1 scenario (1 passed)
7 steps (7 passed)
0m9.781s

If you have any problems you may want to clear the cache from safari.

I used the funfx gem from rubyforge but it’s not up to date. If you want you can get the new code from github, it should have new features.

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Hostname middleware for rails apps on multiple servers

Andrea Franz — Sat, 15 Aug 2009 22:37:36 +0000

If you run a rails application on multiple servers behind a load balancer, almost every time you make a request you have a response from a different host. If you want to know which host has sent back the response, you can use a middleware that adds the hostname in the page title of each request.

lib/hostname.rb:

class Hostname  
  TITLE_REGEXP = /(<title>)([^<]*)(<\/title>)/i
 
  def initialize(app, hostname="")
    @app          = app
    @title_suffix = " - on #{hostname}"
  end
 
  def call(env)
    status, headers, response = @app.call(env)
    add_hostname(response, headers) if headers["Content-Type"] =~ %r{text/html}
    [status, headers, response]
  end  
 
  def add_hostname(response, headers)
    response.each{|s| s.sub!(TITLE_REGEXP, "\\1\\2#{@title_suffix}\\3") if s =~ TITLE_REGEXP}
    headers["Content-Length"] = (headers["Content-Length"].to_i + @title_suffix.length).to_s
    nil
  end
end

To use it, add this line in your environment.rb:

config.middleware.use "Hostname", %x"hostname".chomp

When you don’t need it anymore you can simply remove the line above.

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Testing rails generators with Cucumber

Andrea Franz — Tue, 11 Aug 2009 13:43:59 +0000

In the last days I switched a lot of old projects to use Cucumber, then I started writing test for Web App Theme. Here I haven’t models or controllers to test, because it’s just a generator, but I found enjoyable the use of plain text features to describe the ThemeGenerator behavior:

Feature: Layout generation
  In order to create a great application
  I should be able to generate a layout with Web App Theme
 
  # script/generate theme
  Scenario: Generate a layout    
    Given I have a new rails app
    And I have no layouts
    And I have no stylesheets
    When I generate a theme
    Then I should have a layout named "application.html.erb"
    And I should have a stylesheet named "web_app_theme.css"
    And I should have a stylesheet named "web_app_theme_override.css"
    And I should have a stylesheet named "themes/default/style.css"
 
  # script/generate theme admin
  Scenario: Generate a layout with a name
    Given I have a new rails app
    And I have no layouts
    And I generate a theme with name "admin"
    Then I should have a layout named "admin.html.erb"
 
  # script/generate theme --theme="drastic-dark"
  Scenario: Generate a layout choosing a theme
    Given I have a new rails app
    And I have no stylesheets
    And I generate a theme choosing the "drastic-dark" theme
    Then I should have a stylesheet named "themes/drastic-dark/style.css"
 
  # script/generate theme --theme=bec --no_layout
  Scenario: Generate only stylesheets without layout
    Given I have a new rails app
    And I have no layouts
    And I generate a theme without layout choosing the "bec" theme
    Then I should have a stylesheet named "themes/bec/style.css"
    But I should not have any layouts
 
  # script/generate theme --app_name="My New Application"
  Scenario: Generate layout with application name
    Given I have a new rails app
    And I have no layouts
    And I generate a theme with application name "My New Application"
    Then the layout "application.html.erb" should have "My New Application" as page title
 
  # script/generate theme --type=sign
  Scenario: Generate layout for signin and signup
    Given I have a new rails app
    And I have no layouts
    And I generate a theme for signin and signup
    Then I should have a layout named "sign.html.erb"
    And I should have a layout named "sign.html.erb" with just a box

Here my steps:

Given /^I have a new rails app$/ do
  generate_rails_app
end
 
Given /^I have no layouts$/ do
  remove_layouts  
end
 
Given /^I have no stylesheets$/ do
  remove_stylesheets
end
 
Given /^I generate a theme$/ do
  generate_layout(:theme)  
end
 
Given /^I generate a theme with name "([^\"]*)"$/ do |name|
  generate_layout(:theme, name)
end
 
Given /^I generate a theme choosing the "([^\"]*)" theme$/ do |theme_name|
  generate_layout(:theme, :theme => theme_name)
end
 
Then /^I should have a layout named "([^\"]*)"$/ do |filename|
  layout_exists?(filename).should be_true  
end
 
Then /^I should have a stylesheet named "([^\"]*)"$/ do |filename|
  stylesheet_exists?(filename).should be_true    
end
 
Given /^I generate a theme without layout choosing the "([^\"]*)" theme$/ do |theme_name|
  generate_layout(:theme, :theme => theme_name, :no_layout => true )
end
 
Then /^I should not have any layouts$/ do
  layouts_count.should == 0
end
 
Given /^I generate a theme with application name "([^\"]*)"$/ do |name|
  generate_layout(:theme, :app_name => name )
end
 
Then /^the layout "([^\"]*)" should have "([^\"]*)" as page title$/ do |layout, title|
  layout_title(layout).should == title
end
 
Given /^I generate a theme for signin and signup$/ do
  generate_layout(:theme, :layout_type => :sign)
end
 
Then /^I should have a layout named "([^\"]*)" with just a box$/ do |layout|
  layout_with_box?(layout).should be_true
end

Basically I create a temp folder that I use as fake rails root, and there I launch the generator. After each feature I remove that folder.

And here my env.rb

$:.unshift(File.dirname(__FILE__) + "/../../rails_generators")
require "rubygems"
require "rails_generator"
require 'rails_generator/scripts/generate'
require "fileutils"
require "theme/theme_generator"
 
web_app_theme_root  = File.join(File.dirname(__FILE__), "/../../")
tmp_rails_app_name  = "tmp_rails_app"
tmp_rails_app_root  = File.join(web_app_theme_root, tmp_rails_app_name)
 
Rails::Generator::Base.append_sources(Rails::Generator::PathSource.new(:plugin, "#{web_app_theme_root}/rails_generators/"))
 
module GeneratorHelpers
  def generate_rails_app
    FileUtils.mkdir(File.join(@app_root))
  end    
 
  def remove_layouts
    FileUtils.rm_rf(File.join(@app_root, "app", "views", "layouts"))
  end
 
  def remove_stylesheets
    FileUtils.rm_rf(File.join(@app_root, "public", "stylesheets"))
  end
 
  def generate_layout(*args)
    options = !args.empty? && args.last.is_a?(Hash) ? args.pop : {}
    options.merge!({:destination => @app_root, :quiet => true})    
    Rails::Generator::Scripts::Generate.new.run(args, options)
  end
 
  def layouts_count
    Dir[File.join(@app_root, "app", "views", "layouts", "**", "*.erb")].size
  end
 
  def layout_exists?(filename)
    File.exists?(File.join(@app_root, "app", "views", "layouts", filename))
  end
 
  def stylesheet_exists?(relative_path)
    File.exists?(File.join(@app_root, "public", "stylesheets", relative_path)).should be_true
  end
 
  def layout_title(layout)
    File.open(File.join(@app_root, "app", "views", "layouts", layout), "r").read.match(/<title>([^<]*)<\/title>/)[1]
  end
 
  def layout_with_box?(layout)
    File.open(File.join(@app_root, "app", "views", "layouts", layout), "r").read =~ %r|<div id="box">|
  end
end
 
Before do
  @app_root = tmp_rails_app_root  
end
 
After do
  FileUtils.rm_rf(tmp_rails_app_root)
end
 
World(GeneratorHelpers)

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2 minutes admin layout with rails and the web-app-theme generator

Andrea Franz — Thu, 30 Jul 2009 14:02:19 +0000

Many people found out a rails generator inside my web-app-theme project and asked me how to use it.
Here an example, starting from scratch with a new rails app that manages music Albums.

rails cool_albums
cd cool_albums
script/generate scaffold Album name:string artist:string date:date
rake db:migrate

After creating the first controller with a scaffold or with your hands, start creating a theme:

script/plugin install git://github.com/pilu/web-app-theme.git
script/generate theme application --app_name="My Cool Albums" --theme="drastic-dark"

The first argument (“application”) is the name of the layout that the generator will create (application.html.erb).
The –app_name option specifies the name used as page title, and with the –theme specifies which theme to use among all the available themes inside the plugin.

Now remove the default index.html created by rails and the layout created by the scaffold:

rm app/views/layouts/albums.html.erb 
rm public/index.html

Add the following line in your routes.rb to set the default page of the application:

map.root :controller => :albums

Start the server

script/server

Ok, the layout has been successfully created, but we need to apply a theme for each one of the views generated by the scaffold.

script/generate themed albums album --layout=application --with_will_paginate

With the first 2 arguments I specified the controller path (albums) and the model used (album).
The –layout options is used by the themed generator to know where to add the Albums menu link.

Since we want to use will paginate (we set the –with_will_paginate option), we need to change one line in our albums controller from:

@albums = Album.all

to:

@albums = Album.paginate(:per_page => 10, :page => params[:page])

Here a trick to show form error messages inside the auto generated forms, you can add the following lines in your environment.rb:

ActionView::Base.field_error_proc = Proc.new do |html_tag, instance| 
  if html_tag =~ /<label/
    %|<div class="fieldWithErrors">#{html_tag} #{[instance.error_message].join(', ')}

| else html_tag end end

Ok, restart your server and you are done.

Feel free to fork the project from github to improve the generator or to add a new theme.

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Terror the micro aggregator

Andrea Franz — Tue, 17 Mar 2009 15:55:54 +0000

Terror is a micro feed aggregator made with sinatra and bundled as a gem. It’s very simple to use, just install the gem:

gem sources -a http://gems.github.com
sudo gem install pilu-terror

Create a new project

terror new_aggregator_name
cd new_aggregator_name

Start the server

thin start -C config/thin.yml

Run the feeds fetcher

rake feeds:fetch # run it as a cron job

You can browse the source and fork it on github.

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Radiant Gallery on Dreamhost with Ruby 1.8.7

Andrea Franz — Thu, 15 Jan 2009 15:49:11 +0000

Some people in the past had problems using the Gallery extension on Dreamhost. I didn’t try Dreamhost but someone from the Radiant list solved that problem following these instructions. Check it out if you are on Dreamhost too.

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Getting Exif data using ImageScience

Andrea Franz — Fri, 02 May 2008 09:39:54 +0000

In my current rails project I need to upload photos and save some exif data taken from them. I use attachment_fu as uploading system that let me choose which image processor to use. Using rmagick and mini_magick I can extract exif data with the following code:

# rmagick
image = Magick::ImageList.new(filename).first
puts image['EXIF:Model'] # The camera model used to take the picture
 
# mini_magick
image = MiniMagick::Image.from_file(filename)
puts image["EXIF:Model"]

The problem is that I can’t do the same thing with image_science, because it has no methods that return exif data, so I want to add a method to the ImageScience class to do that.
Looking the FreeImage documentation I found some helpful functions, FreeImage_GetMetadata and FreeImage_TagToString. With these 2 functions I’m able to get an exif tag and convert it to a readable string. Each one of the available tags belongs to one of the following meta models:

FI_ENUM(FREE_IMAGE_MDMODEL) {
  FIMD_NODATA         = -1,
  FIMD_COMMENTS       = 0,	// single comment or keywords
  FIMD_EXIF_MAIN      = 1,	// Exif-TIFF metadata
  FIMD_EXIF_EXIF      = 2,	// Exif-specific metadata
  FIMD_EXIF_GPS       = 3,	// Exif GPS metadata
  FIMD_EXIF_MAKERNOTE = 4,	// Exif maker note metadata
  FIMD_EXIF_INTEROP   = 5,	// Exif interoperability metadata
  FIMD_IPTC           = 6,	// IPTC/NAA metadata
  FIMD_XMP            = 7,	// Abobe XMP metadata
  FIMD_GEOTIFF        = 8,	// GeoTIFF metadata
  FIMD_ANIMATION      = 9,	// Animation metadata
  FIMD_CUSTOM         = 10	// Used to attach other metadata types to a dib
};

Ok, now I can extract the model of the camera:

FreeImage_GetMetadata(FIMD_EXIF_MAIN, bitmap, "Model", &tag);
printf(FreeImage_TagToString(FIMD_EXIF_MAIN, tag, NULL));

As you can see, I need to pass the model of the “Model” tag. But if I don’t know which model to use, I can loop through all of them until the returned value of the FreeImage_GetMetadata function is not NULL:

for(model = 0; model < 11; model++) {
  if(FreeImage_GetMetadata(model, bitmap, tagName, &tag))
    return rb_str_new2(FreeImage_TagToString(model, tag, NULL));
}

Finally I can write a ruby module that extends ImageScience and adds the ability to get an exif tag:

module ImageScienceExifData
 
  def [](key)
    if key =~ /^EXIF:(\w+)?/    
      get_exif($1)
    end
  end
 
  inline do |builder|
    if test ?d, "/opt/local" then
      builder.add_compile_flags "-I/opt/local/include"
      builder.add_link_flags "-L/opt/local/lib"
    end
    builder.add_link_flags "-lfreeimage"
    builder.add_link_flags "-lstdc++" # only needed on PPC for some reason. lame
    builder.include '"FreeImage.h"'
 
    builder.prefix <<-"END"
      #define GET_BITMAP(name) FIBITMAP *(name); Data_Get_Struct(self, FIBITMAP, (name)); if (!(name)) rb_raise(rb_eTypeError, "Bitmap has already been freed")
    END
 
    builder.c <<-"END"
      VALUE get_exif(char *tagName) {
        GET_BITMAP(bitmap);
        FITAG *tag = NULL;
        const char *value;
        int model;
 
        for(model = 0; model < 11; model++) {
          if(FreeImage_GetMetadata(model, bitmap, tagName, &tag))
            return rb_str_new2(FreeImage_TagToString(model, tag, NULL));
        }
 
        return Qnil;
      }
    END
 
  end
end
ImageScience.send(:include, ImageScienceExifData)
 
ImageScience.with_image(filename) do |img|
  puts img["EXIF:Model"]
end

The output with the picture I used is the following :

NIKON
COOLPIX S3
2006:12:10 12:09:17

It doesn’t work with all the exif names but for now it’s ok for my needs. The next step is to add the code above in my rails application and use it with attachment_fu. I’ll write another post about that soon.

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Radiant Newsletter extension has stats

Andrea Franz — Thu, 27 Mar 2008 21:53:04 +0000

Some weeks ago Casper Fabricius sent me a patch for the Radiant Newsletter extension. He added a statistics system to track how many times sent emails are opened. I have finally found the time to apply it and make a commit to my repository. Thank you very very much for your work Casper! I’ll write an article about this extension as soon as possible.

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