Building rhodes application for Blackberry

In this blog we will learn to build rhodes application for Blackberry:

Step 1.) You have to purchase  Blackberry JDE Signature Keys. As you have to sign application before loading it to device. You can purchase this from :

http://na.blackberry.com/eng/developers/javaappdev/codekeys.jsp

This will cost you around 20 US doller.  Signature files can be only registered once per computer. 

Note : You have to enter PIN while filling a form. Please remember this PIN as it will be used later

Step 2.) You will recive 3 .CSI from blackberry. Download this files.

Step3.)  Creating sigtool.csk and sigtool.db files

i)   Double-click on the attachment.
ii)   If a dialog box appears that states that a private key cannot be found, complete steps 3 through 6 before you continue. Otherwise, proceed to step vii.
iii)   Click "Yes" to create a new key pair file.
iv)   Type a password for your private key of at least viii characters, and type it again to confirm.  This is your private key password, which protects your private key. Please remember this password as you will be prompted for it each time signing is attempted or a signature key is installed.
v)   Click "Ok"
vi)   Move your mouse to generate date for a new private key.
vii)   In the "Registration PIN" field, type the PIN number that you supplied on the signature key order form.
viii)   In the Private Key password field, type the password created in step iv.
ix)   Click "Register".
x) Click "Exit".
11) Repeat this process for the other .csi files.

Once this process is complete sigtool.csk and sigtool.db files will be created in bin directory of your Blackberry JDK

Step 4.)Then you can provide password in rhobuild.yml file (located in the Rhodes SDK folder)

build:

   bbsignpwd:

Step 5.) Run this code in your application directory

rake device:bb:production

Step 6.)Now you can check your build in

OTA: /bin/target

You should see many .cod files and one .jad file

Upload all of those files to a web server, then open the .jad file from the browser on your blackberry device

Start Rhosync server on specific port

If you run "rake rhosync:start" by default it will start on port 9292. This command call 'rackup config.ru' without specifying the port
To start Rhosync server on Specific Port you can use 


rackup -p <port> config.ru 


Example : rackup -p 80 config.ru 

Create a Rhodes application which will sync data from rails application using Rhosync

In this blog we will create a Rhodes application which will synchronize your data from rails application through Rhosync.

We need to create 3 applications

1. Rails Application: It will feed data in json or XML format.
2. Rhodes Application: This code will be installed in mobiles.
3. Rhosync Application: These will sync the data from rails App to Rhodes Application in your phone

Steps to create rails Application:

I will just create a rails application using scaffold:

1. rails employee_details
2. cd employee_details
3. Ruby script/generate scaffold employee name:string phno:integer address:text
4. Update your database.yml 
5. Rake db:migrate
6. Add these code in your employees controller (you can skip this step if you want to only show employee details and does not do crud operations.)

              protect_from_forgery :except => [:create, :update, :delete]

    

    7. Add this line under response in controller:

             

             format.json { render :json => @employee }

    8. Once it is done we will run it on port 3000:

              http://localhost:3000\employees.json

         we will get output in json format.

Steps to create Rhodes application:

1. Rhogen app employee
2. Cd employee
3. Rhogen model employee name,phno,address
4. Add link in index.erb to your index page
5. Enable sync in model Employee  

                enable :sync

    6.   Edit rhoconfig.txt file and set

             syncserver = 'http://localhost:9292/application

    7.    rake run:bb

Steps to create Rhosync application:

1. Rhosync app employee_server
2. Rhosync source employee
3. Then employee.erb incude json and rest client

          require 'json'

          require 'rest_client'

     4. Update the query method

  def query(params=nil)

    parsed=JSON.parse(RestClient.get("http://localhost:3000/employees.json").body)

    @result={}

    parsed.each { |item|@result[item["employee"]["id"].to_s]=item["employee"] } if parsed

    @result

  end

Now you can test this by login to your simulator.

Bug in rhodes-translator- 0.0.1 template

As metadata in Rhodes is very new, few of the templates in rhodes_translater gem has bugs.

I tried to use select box using metadata. But it's field was not saving the field value.

There is small bug in select.rb in rhodes_translator gem so I modified this file. So to fixed this issue:

Replace the file select.rb in

C:\Ruby187\lib\ruby\gems\1.8\gems\rhodes-translator- 0.0.1\lib\rhodes_translator\templates

with this new select.rb
(Download it from link below)

http://www.4shared.com/dir/HuEjDnVw/sharing.html

Creating a Rhodes Application which will synchronize your tweets to your phone

In this blog I will create a Rhodes application which will sync your tweets through rhosync.

I am currently using Rhodes 2.1.0 and Rhosync 2.0.6.

If you want to some complex operation you can read twitter API docs:

http://dev.twitter.com/doc/get/statuses/user_timeline

Step 1.) Create a Rhodes Application

1.) Go to command prompt and create Rhodes application

>rhogen app twitter-api

>cd twitter-api

>rhogen model twitter text

2.) Now update index.erb( Adding a link to index page of Twitter controller

link_to “Twitter”, :controller => :Twitter

3.) Enable sync in Twitter model.

Update twitter.rb and add the following line

enable sync

4.) Update rhoconfig.txt(Setting the path for rhosync server)

syncserver = ‘http://localhost:9292/application’

5.) Start the simulator

rake run:bb

Step 2.) Create Rhosync Application

1.) Go to command promt

>rhosync app twitter –server

> cd twitter-server

>rhosync source twitter

2.) Update the source adapter twitter.rb

require ‘json’

require ‘open-uri’

Add this code in query method:

def query(params=nil)

parsed=""

open('http://api.twitter.com/1/statuses/user_timeline.json?screen_name=nalwayaabhishek') do |f|

parsed=JSON.parse(f.read)

end

@result = {}

parsed.each do |item|

item_hash = {}

item_hash['text'] = item['text']

@result[item['id'].to_s] = item_hash

end

@result

end

3.) Start redis server

rake redis:start

4.) Start rhosync server

rake rhosync:start

By default it will start on port 9292.

Once the simulater is started Login with any username and password. And sync the data.

Now you can see your tweets even if you are offline.

Nokogiri HTML and XML parser

Nokogiri gem, a new HTML, XML, SAX and Reader parser for Ruby.

It parses and searches XML/HTML faster than Hpricot(Hpricot being the current de facto Ruby HTML parser) and boasts XPath support, CSS3 selector support (a big deal, because CSS3 selectors are mega powerful) and the ability to be used as a "drop in" replacement for Hpricot.

On an Hpricot vs Nokogiri benchmark, Nokogiri clocked in at 7 times faster at initially loading an XML document, 5 times faster at searching for content based on an XPath, and 1.62 times faster at searching for content via a CSS-based search.

Here is the example :

require 'nokogiri'

require 'open-uri'

# Get a Nokogiri::HTML:Document for the page we’re #interested in...

doc = Nokogiri::HTML(open('http://www.google.com/search?q=tenderlove'))

#Do funky things with it using Nokogiri::XML::Node methods...

# Search for nodes by css

doc.css('h3.r a.l').each do |link|

puts link.content

end

####

# Search for nodes by xpath

doc.xpath('//h3/a[@class="l"]').each do |link|

puts link.content

end

####

# Or mix and match.

doc.search('h3.r a.l', '//h3/a[@class="l"]').each do |link|

puts link.content

end

Source : http://nokogiri.org/

My libraries in lib folder is not loading for Rails3..

My libraries in lib folder is not loading for Rails3!!!

Is it a bug?...NO

In Rails 3 it does not automatically load files in lib folders. . If you create any module/class in lib folder and try to use it, the server will throw an "uninitialized constant Modulename (NameError)". You have to manually include the modules which you want to use.

The possible reason for this behaviour is:

• This makes a Rails application behave more closely to any Ruby project, leaving the autoload to directories specific to Rails .
• Increasing performance.
• Autoloading in lib was always causing some pain, since some people had files like "employee.rb" but there was no "employee" module defined it.

There is solution to unable this feature again:

Put this in application.rb

config.autoload_paths += %W(#{config.root}/lib)

config.autoload_paths += Dir["#{config.root}/lib/**/"]