Drupal

Drupal

Come for the software, stay for the community

Drupal is an open source content management platform powering millions of websites and applications. It’s built, used, and supported by an active and diverse community of people around the world.

Drupal Home page : http://drupal.org/

Why choose drupal ?

Drupal is a free software package that allows you to easily organize, manage and publish your content, with an endless variety of customization.

Reasons are many,

Drupal is Open Source | Community Support | Commercial Services |Who's Using Drupal |Drupal CMS Features

Drupal Downloads
http://drupal.org/download

Drupal Groups

http://groups.drupal.org/

Drupal tutorials
http://www.siteground.com/tutorials/drupal-tutorial/


Drupal Wikipedia Page
http://en.wikipedia.org/wiki/Drupal

42. What is Content Construction Kit (CCK) in Drupal

The Content Construction Kit allows you to add custom fields to custom content types using a web interface. In Drupal 5.x, custom content types can be created in Drupal core, and the Content Construction Kit allows you to add custom fields to any content type. In Drupal 7 and later, most of the functionality of CCK has been absorbed into Drupal core.

Summary and purpose of CCK?


Drupal comes with core content types like story and blog. For such a content type, go to 'Create content' and submit a new story or blog. That's sufficient for pages of pure text and with or without attachments.

But what if your users want to be able to submit reviews of their favorite aardvark? That would be a new content type, but I want to be able to display other stuff as well as a chunk of text for every node of that type, and I don't want it to be just attached file links.

My options: I could hack the story.module, OR I could see if someone has already created an aardvark.module for the exact type of content I want, OR using CCK I could create a new content type called Aardvark Review.

Using CCK, I can create a content type that has exactly the fields I need, no more or less. My Aardvark Review for instance might have:

text field (comments on the aardvark)
dropdown menu (aardvark color)
audio file (recording of the aardvark's grunting)
image (photo of aardvark)
The CCK admin interface for creating these new content types is nice and easy: just create your new type and then click through, adding the type of fields you want it to have and what their parameters will be (how much text for the review? which colors in the dropdown menu?). There are many add-ons available in the downloads section under CCK that add new kinds of fields to your options (video field, audio field, calculated values and vastly more complicated ones).

From the users' perspective, they'll just click on Create content > Aardvark Review and get a form that asks them to submit their review, the aardvark's color, a recording, and picture.

Further Reading http://drupal.org/modules/cck/documentation

Module Download Page http://drupal.org/project/cck

Module Download Link http://ftp.drupal.org/files/projects/cck-6.x-2.9.tar.gz

41 The Drupal flow

If you want to go deeper with Drupal, you should understand how information flows between the system's layers. There are five main layers to consider:






At the base of the system is the collection of nodes—the data pool. Before anything can be displayed on the site, it must be input as data.
The next layer up is where modules live. Modules are functional plugins that are either part of the Drupal core (they ship with Drupal) or they are contributed items that have been created by members of the Drupal community. Modules build on Drupal's core functionality, allowing you to customize the data items (fields) on your node types; set up e-commerce; programmatically sorting and display of content (custom output controlled by filters you define); and more. There are thousands of different options within the fast-growing repository of contributed Drupal modules. They represent the innovation and collaborative effort of everyone from individuals to large corporations.
At the next layer, we find blocks and menus. Blocks often provide the output from a module or can be created to display whatever you want, and then can be placed in various spots in your template (theme) layout. Blocks can be configured to output in various ways, as well as only showing on certain defined pages, or only for certain defined users.
Next are user permissions. This is where settings are configured to determine what different kinds of users are allow to do and see. Permissions are defined for various roles, and in turn, users are assigned to these roles in order to grant them the defined permissions.
On the top layer is the site theme (the "skin"). This is made up predominantly of XHTML and CSS, with some PHP variables intermixed, so Drupal-generated content can go in the appropriate spots. Also included with each theme is a set of functions that can be used to override standard functions in the modules in order to provide complete control over how the modules generate their markup at output time. Templates can also be assigned on-the-fly based on user permissions.
This directional flow from bottom to top controls how Drupal works. Is some new functionality you want not showing up? Perhaps you uploaded the module into the system but have not activated it yet, and this is making everything downstream non-functional (as in "A" in the diagram above).

Maybe the module is installed and activated, but you still don’t see what you want on your site. Did you forget to place the block, as in "B"? Or are your user permission settings conflicting with what you want and your users are not set to see the output as in "C"?

Additionally—as mentioned earlier—getting the kind of granular control you want over the details of the XHTML module outputs requires understanding this flow. Are you using a module that does exactly what you want, only you wish the markup was just a little bit different? Maybe you’d like it to use different tags, or you’d like to assign a CSS class to something? You accomplish this by copying the output function from the module and pushing it up to the functions document in your theme. Modify the code there, and when the system goes to output, it will see your customized function and use that instead.

40. The search features in Drupal are excellent, as compared to search in other content management systems. What makes these so good?

Drupal's search is so good because Drupal doesn't treat its content as a big bucket of text; rather, all of the fine-grained semantic information that Drupal knows about can be used to fine-tune search results. That includes the type of content, any classification information from the taxonomy system, and the usual content metadata. Inside the search engine is an extensible indexer that can accept pretty much anything. In the book, one of the examples uses Drupal to index an external non-Drupal database.

And as usual, you can tweak and override the search system to adjust the user interface, the way content is ranked, and the way results are displayed. That said, Drupal integrates well with external search engines such as Apache Solr, Xapian, and Sphinx if the built-in Drupal search does not meet your needs.


source: http://ostatic.com/blog/interview-john-vandyk-author-of-pro-drupal-development

39. Drupal is flexible at handling events automatically and employing triggers. How do developers make use of these features?

There are really two answers here. At the code level, that's always what Drupal has been about: having your code run when a certain event happens. For example, the following code would send a tweet to my Twitter account every time someone logs in to the Drupal site (it requires the third-party Twitter Module to be installed to do the dirty work).

function mymodulename_user($op, &$edit, &$account) {

if ($op == 'login') {

// Bring twitter-related functions into scope.

module_load_include('inc', 'twitter');

// Use t() for proper localization.
$text = t('@username logged in', array('@username' => $account->name));

// Post to twitter using the twitter module.
twitter_set_status('clouseau', 'secret', $text);

}

}

That's fine if you are a programmer. But what if we took the whole idea of "Send a message to Twitter" and abstracted it? Then we could use a nice user interface to associate the action "Send a message to Twitter" with one of Drupal's common events, such as when a user logs in, or posts content, or creates a new account. That is what the new features in Drupal 6 provide: the user interface for doing such associations between actions and events. A trigger is an event that has been exposed in the user interface.

You can also create your own triggers. Perhaps you want to go the other way: you want actions to happen in Drupal when a new tweet is posted to your Twitter account! Chapter 3 of the book tells you how to make your own triggers.

source: http://ostatic.com/blog/interview-john-vandyk-author-of-pro-drupal-development

38. what a module is in Drupal and what the process of writing one involves?

When developers learn that modifying Drupal's core code is a no-no, they often have a panic moment. "How, then will I bend Drupal to do my will?," they ask. Easy: by writing a module. The first part of writing a module is writing a .info file, where you describe your module to Drupal. Here's an example from the Forum Module:

; $Id: forum.info,v 1.6 2007/06/08 05:50:54 dries Exp $

name = Forum

description = Enables threaded discussions about general topics.

dependencies[] = taxonomy

dependencies[] = comment

package = Core - optional

core = 6.x

This gives Drupalenough information to list the module on the modules administration page, and to tell whether the module is compatible with the version of Drupal being run (in this case, 6.x). Drupal will also make sure the dependent modules are present.

A module may have a .install file containing code that runs when the module is first installed. For example, some database tables may be needed, or some values may need to be initialized in Drupal's persistent variable system.

Finally, the .module file itself contains the code that does whatever it is that your module will do. And that's just about anything. There were 3,430 modules in the repository last time I checked, so it's a good idea to check if the module you're thinking about writing is already written. Drupal Modules is a good place to do that.

New Drupal developers are also often stymied by the question "When does my code run? I put it in a module, but when does the module run?" Answering that question requires understanding of the Inversion of Control design pattern that Drupal uses, often called "hooks" or "callbacks". You name your functions in a certain way, and Drupal will automatically call your code at the appropriate time, depending on how you've named the functions.

source: http://ostatic.com/blog/interview-john-vandyk-author-of-pro-drupal-development

37. Which are the core optional modules in drupal 6.x ?

1. Aggregator Aggregates syndicated content (RSS, RDF, and Atom feeds).
2. Blog Enables keeping easily and regularly updated user web pages or blogs.
3. Blog API Allows users to post content using applications that support XML-RPC blog APIs.
4. Book Allows users to structure site pages in a hierarchy or outline.
5. Color Allows the user to change the color scheme of certain themes.
6. Comment Allows users to comment on and discuss published content.
7. Contact Enables the use of both personal and site-wide contact forms.
8. Content translation Allows content to be translated into different languages.
9. Database logging Logs and records system events to the database.
10. Forum Enables threaded discussions about general topics.

11. Help Manages the display of online help.
12. Locale Adds language handling functionality and enables the translation of the user interface to languages other than English.

13. Menu Allows administrators to customize the site navigation menu.
14. OpenID Allows users to log into your site using OpenID.
15. Path Allows users to rename URLs.
16. PHP filter Allows embedded PHP code/snippets to be evaluated.
17. Ping Alerts other sites when your site has been updated.
18. Poll Allows your site to capture votes on different topics in the form of multiple choice questions.
19. Profile Supports configurable user profiles.
20. Search Enables site-wide keyword searching.
21. Statistics Logs access statistics for your site.
22. Syslog Logs and records system events to syslog.
23. Taxonomy Enables the categorization of content.
24. Throttle Handles the auto-throttling mechanism, to control site congestion.
25. Tracker Enables tracking of recent posts for users.

26. Trigger Enables actions to be fired on certain system events, such as when new content is created.
27. Update status Checks the status of available updates for Drupal and your installed modules and themes.
28. Upload Allows users to upload and attach files to content.

36. Is it possible to disable the core required modules through drupal admin ?

No, it is not possible to disable the core required modules.

35. Which are the core required modules in drupal 6.x ?

1. Block --- Controls the boxes that are displayed around the main content.
2. Filter --- Handles the filtering of content in preparation for display.
3. Node --- Allows content to be submitted to the site and displayed on pages.
4. System --- Handles general site configuration for administrators.
5. User --- Manages the user registration and login system.

34. How to enable clean urls in drupal ?

The standard Drupal installation contains a sample .htaccess file which supports clean URLs. It is easy to miss copying this file, because of the leading "dot". So before trying to enable Clean URLs, make sure this file exists in your Drupal installation.

Drupal 6.x
In Drupal 6, the installer tests for compatibility with Clean URLs as a part of the installation process.
Drupal 5.x
Goto the administer >> site configuration >> clean urls section of the administrative interface.
Clean urls can be enabled by following the above two options in respective versions of drupal website.