First, lets make a checkbox called finish; this link will send the id of the item to the database to be updated. The item will be a todo and we will be using the list.html.erb and the todo_controller.rb.

In the view named: list.html.erb

remote_function(:url => {:action => 'finish', :controller => 'todo',
:id => todo.id})

Now once the checkbox is clicked it will them make the Ajax call to the todo_controller.rb with the method finish.

In the controller: todo_controller.rb

def finish
	@todo = Todo.update(params[:id], :status => '1')
	if @todo.save
		render :update do |page|
		page.replace_html 'thedivID' + params[:id], 'Finished!'
		end
	end
end

The above code will first update the database setting the status from 0 to 1 (1 = finished and 0 = unfinished). Next we check if the update was successful, after that we render the update to the page. By using render :update, we can replace the html in side of the div or other element with the text ‘Finished’.

Note you can use remote_function in any way you see fit, ie: onclick, onload and others.

Passing another var with remote_function. lets say i want to pass the user id, list id and, the todo id. How would we do this with the remote function?

We know know the link should look like this: /todo/finish/17?todoid=72&userid=100, but how do we do this with rails? Below is how to do just that;

remote_function(:url => {:action => 'finish', :controller => 'todo',
:id => list.id, :todoid => todo.id, :userid => @user.id})

# Added V1.7b
textlink_do_fade
textlink_do_puff
textlink_do_blindup
textlink_do_dropout

You can build any of the above calls with:

textlink_do_fade('Link Text','divYouWantToUpdate',{***},{****})

Visit the project for more info on how to use the latest methods and more. Winn Scriptatype project home page. at Ruby On Rails Railway.

[ruby]
# New calls in 1.7b
textlink_do_fade
textlink_do_puff
textlink_do_blindup
textlink_do_dropout
[/ruby]

I expect i will be making the same update to the PHP version soon so keep an eye out for that!

Take a look at the WinnScriptatype:Rails RubyForge project page and download the latest!

I had been working on this plugin for a few weeks in making a new application. I kept writing the “input, Ajax.Request and, Effect.Fade”, so i needed a way to make that fast and do what i need. And out came this handy plugin!

[ruby]
# Lets use this new plugin
checkbox_do_fade(‘theDiv’, ‘CheckboxID’, {:controller => ‘todo’, :action => ‘finish’, :id => todo.id}, {:userid => user.id})

[/ruby]

Here is an over view of the options:

[ruby]
checkbox_do_fade(‘*’, ‘**’, {***}, {****})

[Element ID]* This is the name of the element you want to effect such as a div or table (tr,td)…

[Checkbox ID]** This is the id of the checkbox it self

[URL/path]*** this is the url for the update to take place NOTE: always use controller,
action, and id DO NOT place other variables in this block that is for the next block.

[URL/path options]**** This block is used for url options like so: (/path/to/1?userid=1) as you see
userid is 1, this is done by using the url options block. You may send an unlimited number of
url options with this.

# Below are the ONLY supported calls
checkbox_do_fade # This will fade the element
checkbox_do_puff # This will puff the element
checkbox_do_blindup # and so on…
checkbox_do_dropout # again…
[/ruby]

Ready to start using it? Download WinnScriptatype

You will also need help installing this plugin so take a look at Ruby on Rails Railway : WinnScriptatype.

Below is how my database.yml file looks:

[ruby]
databaseone:
adapter: mysql
database: one
username: root
password:
host: localhost

databasetwo:
adapter: mysql
database: two
username: root
password:
host: localhost

production:
adapter: mysql
database: three
username: root
password:
host: localhost
[/ruby]

Now in my environment.rb file i have:

[ruby]
module Dbone
establish_connection :databaseone
end
module Dbtwo
establish_connection :databasetwo
end
[/ruby]

Now if i would like to select from my database one i do the following in any controller:

[ruby]
def index
@users = Dbone::Users.find(:all)
end
[/ruby]

Get the idea now? It’s the same to update and add to the database. Just use the module name. Now for the “production” database everything remains the same, no need to add a module to it.

Get Magic Multi-Connections V1

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render :update do |page|
      page.html_replace 'testdiv', params[:the_text_added]
 
      page.delay(1) do 
        page.visual_effect :highlight, 'testdiv', :duration => 2
      end
end

Cool huh? Try it out and see what you can do with delay()!

Need more help with rails? Here is a great book that i recommend for all new and old rails developers: Beginning Ruby: From Novice to Professional

[ruby]
:complete => visual_effect(:highlight, ‘theDivId’)
[/ruby]

Just give it the div or element id and it works like a charm!

Don’t know how to use remote_function? Check out this post: Using remote_function

So lets say I am going to tell Dir.glob to look in my “files” folder. The path I need to feed it is starting from the root of my app so the path would be “public/files/”.

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@files = Dir.glob("public/files/*")

I added “*” so I can pull all files and dir’s back. If I just want to pull PDF’s back I can use this:

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@files = Dir.glob("public/files/*.pdf")

That will show all PDF’s in that folder. You may also give it a file name and just pull one file out.

Anyway back to example one, I am looking for all files and all directories in the folder “files”. Below is the array I get back from @files.

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for file in @files
 
puts file
 
end
#====
Output is:
 
public/files/test1.gif
public/files/test2.gif
public/files/folder

This is the best way I have found for pulling files from a directory and listing them in an array.

Need more help with rails? Here is a great book that i recommend for all new and old rails developers: Beginning Ruby: From Novice to Professional

I figured that it would be an awfully easy task to download pictures from the internet using Ruby, and it is, but it was very difficult to find good examples. I googled for an hour or so, and kept coming up empty-handed. Finally, I checked in gmail where I keep mail from the Ruby Language mailing list. I found a relatively straightfoward way to do this.

Let’s say that you want to download a picture from flickr, and you know its URL. Here’s the ruby script to download the file:

[ruby]
require ‘net/http’
Net::HTTP.start(“static.flickr.com”) { |http|
resp = http.get(“/92/218926700_ecedc5fef7_o.jpg”)
open(“fun.jpg”, “wb”) { |file|
file.write(resp.body)
}
}
[/ruby]

The Net::HTTP class contains the magic needed to handle this operation. I don’t think this will work at all if you need to pull down a file from an FTP server. For now, we’re dealing with http urls. So, just strip off the “http://” portion of the url and everything after that up to the first / goes into the start method.

Now, we get the file. The rest of your image url after what you put in the start method goes into the get method. This grabs the file from flickr.

Now we’re going to copy the file down to where the script is running. First, let’s create the file we’re going to copy the picture into. Using the open method, the first parameter is the name of the file that you’re going to plop the picture into. We could have used “218926700_ecedc5fef7_o.jpg” or anything else here. The second parameter of the open method, “wb” indicates that we’re opening the file for (w)riting and we’re going to be writing (b)inary information. The “b” may not be necessary on non-Windows platforms.

Finally, we’re going to write into the new file, the contents or “body” of what we grabbed from flickr. So, this writes in the binary bits of the picture into fun.jpg. Remember that with the way that we created fun.jpg it’ll be in the same directory with our ruby script.

This same method will copy down .html files, .css files, .pdf’s and just about any other kind of file. In my next RubyNoob entry, I’ll write about how to combine this method with a flickr api call to grab an arbitrary number of recent photos from flickr. As usual, I’m still a noob, and there’s probably much better ways to do this. If you know a better way, please share in the comment section below.

Keeping that application secure is important, so when do you start worrying about security? I say right away, start building your application with maximum security. Keep track of what cookies you are setting as they can be in danger from a JavaScript injection.

So if your application has to use cookies how should you authenticate the user? I find writing a session id to the database and to a cookie along with a username or email, this process becomes very easy and secure. So how does this work?

Start with a login or registration, and then start the session. Pull the session id into a variable the send it to the database. After that write the session id to a cookie.

[php]
session_start();
$sid = session_id();

// your SQL insert or update “UPDATE accounts SET sid=’$sid’ WHERE id=1″

setcookie(‘appname_session’, $sid, time()+3600);
[/php]

After setting the session id cookie we need to set the username or email cookie!

[php]
setcookie(‘appname_user’, $username, time()+3600);
[/php]

Now you are able to authenticate the user inside your application securely.

[php]
// Select the user now
find_by_username_and_sid(cookie(“appname_user”),cookie(“appname_session”));
[/php]

This is in PHP but the same idea applies in all languages.