Greasemonkey-Reforming The Internet with Its End Users

Hi friends,
                Greasemonkey is basically a fire fox extension which allows users to install scripts that make on-the-fly changes to HTML web page content on the DOMContentLoaded event, which happens immediately after it is loaded in the browser.
        
Created by Aaron Boodman and Released on 2004-12-06.

Firefox Extension but also works for SeaMonkey, Opera, Chrome, Safari and IE.

Simply we can define Greasemonkey = JS+DOM(+CSS).

Din't get much??dont wory as the journey goes on you wil be cleared with all the terms...

Its ok man, but now a days almost all web pages are attractive, then what is the Need OF Greasemonkey??

You are right buddy but making changes in HTML page appearing in your browser as per your convenient is not the only purpose of  greasemonkey..lets see its basic need

• Browsers and the Internet expose operating systems to environments that are malicious.
• To make the websites you visit more secure.
• Changing features of some websites according to user will.

      What are Other Features??

• Customize the way a web page displays or behaves, by using small bits of JavaScript.
• Automatically retrieve data from other sites to make two sites more interconnected. 
• Suppressing the advertisements on a page.
• Altering links that redirect so that they go directly to the desired target.

     I hope now you are cleared with why we should greasemonkey...

What is User Script??

• A user script is just a chunk of Java script code, that tells Greasemonkey where and when it should run. 

• Greasemonkey scripts are persistent.

• A user script can do anything user can do in Javascript.

    Installing Greasemonkey...

     To obtain all the applications discussed in the theoretical details we should install it from http://diveintogreasemonkey.org/ to Mozilla Firefox.To start writing user scripts, you first need to install the Greasemonkey browser extension, version 0.3 or later.

Procedure: Install the Greasemonkey extension

1. Visit the Greasemonkey home page <http://greasemonkey.mozdev.org/>.

2. Click the link titled "Install Greasemonkey". Firefox will indicate (probably at     the top of your browser window) that it prevented the site from installing software. Click Edit options... to bring up the "Allowed Sites" dialog, then click Allow to add the Greasemonkey site to your list of sites that are allowed to install software.

3. Click OK to close the "Allowed Sites" dialog.

4. Once again, click the link titled "Install Greasemonkey".

5. Now an install dialog should pop up to confirm that you really want to install. Wait a few seconds for the install button to enable, then click Install now.

6. Restart your browser.

   

          Once you restart your browser, select the Tools menu. You should see three new menu items: Install User Script..., Manage User Scripts..., and User Script Commands. Only Manage User Scripts... will be enabled, but that's OK. The others only become enabled under special circumstances.

        By default, installing Greasemonkey does not add any functionality to your browser (other than those three menu items). All it does it enable you to install additional items, called "user scripts", which customize specific web pages.

Start writing your first user script "Hello World !"..

 

               Fig 1.0 Entry for writing user script

        As in fig. 1.0, one can create his own script. Tool > Greasemonkey> New User Script will open a new window asking about the basic information about the script.

                          Fig 1.1 Window opened after clicking on New Script

Name: The name of your script i.e. the user script.

Includes: The URLs of the webpages which you expect the script to act over.

OK for the first time will prompt you for selecting the Text Editor. You can use Gedit (/usr/bin/gedit) or Notepad (Installation_drive:\Windows\notepad.exe) for editing.

                                                           Fig 1.3 Hello World script!!!

        The name for the script is “Hello World” and it will act over http://www.google.co.in/* webpage. OK will open the text editor with some auto-generated comments.

                                         Fig. 1.4 Window opened after clicking on OK.

              As mentioned earlier, it’s all JavaScript. The name of file containing the script must end in “user.js” (hello_world.user.js). alert(‘Hello, World!’);

                                                       Fig.5 Printing ‘Hello world!’                        You are, now, ready with your first user-script. Type http://www.google.co.in in your Firefox browser to see the alert.

  

Fig 1.6 

So i think now you are familiar with greasemonkey..Lets have some fun with greasemonkey

1) Redirecting Link of facebook to google

              Write a new script window.location=’http://www.google.com’ and write “http://www.facebook.com” in the include section. With this whenever there’s a Facebook link you will always get redirected to Google.

2)   Obtaining Download button to Youtube

    Here’s a script for downloading YouTube’s videos: https://docs.google.com/document/pub?id=1Hlmy2IbEk44mI4IKpzJQ8HCJLzdgvW5binwP-_fLOI . There is a install button click it and the script will be installed. There is also a button of source code click on it to see script for this. After installing script open youtube.com and we will find a Download button bellow the video. 

                                     Fig 1.7 Download button to Yuo Tube

 3)  Facebook Security

            To Redirect Gmail to an equivalent https:// secure address we hav to simply write the following script.

             window.location.href = window.location.href.replace(/^http:/, 'https:');

          This user script is very simple. Most of the "work" is accomplished by the @include line: // @include   http://facebook.com/*. This user script only runs if the @include matches.

                                    Fig 1.8 Secure Facebook connection

Still you have any difficulty, you can watch following video showing the demo of how link redirect from google to facebook, How you can manage your script and to change the contents of HTML page..

So now I hope you enjoyed the journey of greasemonkey. For any query or suggestion you can post here..

Thank you !!!