Drupal Interview Questions And Answers

Drupal (pronounced Dru-Pull) is an open source content management system offering a toolset that rivals those of most commercial alternatives. With integrated social media and e-commerce functionality, it provides unique value as part of your social media strategy.

Drupal is the choice for many great web sites because it does a lot of different things very well, and allows different kinds of information to interact effectively through its flexible, open architecture. Compared with commercial or custom solutions, Drupal's feature set is far more economic and practical for most organizations.

Trellon has built Drupal sites and deployed them in very demanding scenarios, serving millions of page views a day. Drupal scalability and performance optimization is one of our core competencies, and we often work with existing web properties to find ways to improve their performance. Contact us to discuss your specific needs.

A wide range of support services are available for organizations running Drupal sites. The Drupal community itself is an excellent resource for people looking to learn more about the platform or resolve specific issues that emerge using the system. Acquia offers an enterprise distribution of Drupal that includes uptime monitoring, email and telephone based troubleshooting support, and subscription plans for sites with varying performance requirements.

For hosting, Our works with a variety of partners to deliver solutions to ensure sites are operational and can scale to meet changing traffic expectations. Rackspace is Our preferred hosting partner, and their 100% uptime guarantee allows us to focus on building great web sites without worrying about the network. Workhabit and Amazon S3 offer cloud hosting solutions that allow us to build sites that automatically scale to handle large peaks of traffic, and to provision new servers dynamically based on actual traffic conditions on any given day.

Drupal is often compared to a number of commercial content management systems including Crown Peak, Expression Engine, Clickability and Site Life in terms of capabilities. None of these systems offer the range of features that can be found in Drupal or the flexible, developer-friendly architecture that allows us to rapidly deploy dynamic web sites. In terms of sustainability, these platforms charactertistically lack the innovative approach to development embraced by the Drupal community, with updates and new features continually being added to the platform. These systems typically do surpass Drupal in terms of out-of-the-box reporting and metrics tools, generally providing views of data that is also stored in other systems. For instance, detailed page tracking information can just as easily be pulled from a CDN and integrated into a Drupal site for much less than the costs of per-seat licenses from a commercial vendor over a 1 month period.

Drupal is also often compared with other open source content management systems including Joomla, Plone, Scoop, Silverstripe, Typo3, Graffitti, Moveable Type and Wordpress. There are characteristic features to all of these systems that make them appropriate in certain contexts, and most of them compare favorably to Drupal in one category of operation or another. Few of them, however, are capable of offering the balance between performance and functionality found in Drupal.

Another common alternative platform to Drupal is Ruby on Rails. We really don't have much to say about Ruby except that it is a framework moreso than a platform. There are some characteristically challenging web development tasks that are quite easy to do with Ruby, and there are others which are infinitely more complicated than they should be.

One big difference is the fact that Ruby lacks the refined data object model found in Drupal that ensures interoperability between various aspects of the system, such as adding new modules to modify the operations of others. Whereas Drupal offers a self-generating database schema for many modules and underlying components of the platform, Ruby on Rails emphasizes a design philosophy holding that simplification of code conventions leads to better outcomes. While this all sounds good in principle, we have found there are certain tasks that make adherance to this philosophy an ideal moreso than a practical goal and breaking free from these conventions when necessary a daunting task (especially when integrating with external systems).

Symptoms: An authorized Drupal user loses "edit" access to nodes they've created, even if they have appropriate node (or other module) access permissions. Or, user cannot edit a node that should be editable by them, based on access control or node access settings. No errors or warnings are presented to the user. Nothing in the Drupal watchdog log.

Possible Cause: The user does not have permission to use the input filter currently assigned to the node. (An administrator or other privileged user may have changed the input filter settings, or, input filter permissions may have been changed to exclude the node author since the node was created. As a result, the user never had, or no longer has permission to use the input filter associated with the node.)

A minimum base installation requires at least 3MB of disk space but you should assume that your actual disk space will be somewhat higher. For example, if you install many contributed modules and contributed themes, the actual disk space for your installation could easily be 40 MB or more (exclusive of database content, media, backups and other files).

The standard release of Drupal, known as Drupal core, contains basic features common to content management systems. These include user account registration and maintenance, menu management, RSS-feeds, page layout customization, and system administration. The Drupal core installation can be used as a brochureware website, a single- or multi-user blog, an Internet forum, or a community website providing for user-generated content.
As of August 2011 there are more than 11,000 free community-contributed addons, known as contrib modules, available to alter and extend Drupal's core capabilities and add new features or customize Drupal's behavior and appearance. Because of this plug-in extensibility and modular design, Drupal is sometimes described as a content management framework. Drupal is also described as a web application framework, as it meets the generally accepted feature requirements for such frameworks.

One of the common (mostly unfounded) complaints about Drupal has been, "Drupal is slow." You want to hire a developer who understands Drupal's built in caching system, and what its limitations are. For example, Drupal 6's block cache will not appreciably speed up the page if the user is logged in.
Ask your candidate to recommend some additional solutions to speed up Drupal's caching. These could include the Boost module, Varnish, Squid, Memcache or Pressflow. Ask if they've ever run into issues with Drupal's cache.

You can set your Drupal site in off-line mode, while it is being developed. Just click Administer » Site maintenance. There you can set the status to off-line. If you wants, you can also set your own custom off-line message. When set to Off-line, only users with the administer site configuration permission will be able to access your site to perform maintenance; all other visitors will see the site off-line message configured there. Authorized users can log in during Off-line mode directly via the user login page.

This is another common question among Drupal newbies all time. After trying out all available themes under Drupals theme directory, we may naturally want to try new themes. Installing a new theme is very simple and straightforward. Follow the steps below.
Download a new theme package. Note that themes for different Drupal versions are not compatible, version 5.x themes do not work with Drupal 6.x and reverse.
Read any README or INSTALL files in the package to find out if there are any special steps needed for this theme.
Upload the contents of the theme package to a new directory in the themes directory in your Drupal site. In Drupal 5.x & 6.x, you place your themes in /sites/all/themes/yourThemeName
Click administer » themes and enable the new theme (Drupal will auto-detect its presence).
Edit your user preferences and select the new theme. If you want it to be the default theme for all users, check the default box in the themes administration page.

After finding and downloading a module, the next step would be to copy it the modules folder. Most people copy the file to the default modules folder here http://sitename.com/drupal/modules this is where all the modules that ship with Drupal are stored so it seems somewhat logical to do this. But this folder is actually meant to store only Drupal's default modules. Instead you should go to http://sitename.com/drupal/sites/all folder, there you will see a readme.txt file. This file will clearly tell you the trick. You just need to create a new folder named modules here. Now copy the modules folder here. That's all, you have successfully installed the module.
Next step would be to enable the module through the Admin interface. To do this navigate to Administer » Site Building » Modules. Here you will see a list off all installed modules, and our newly installed module will also be listed here. You just have to check the enable check box against the new module and then click the Save Configuration button. That's all.

Login to cPanel -> Databases box -> phpMyAdmin;
► Select the Druapl database folder from the left navigation bar. The page will refresh and and the Drupal database's tables will be displayed on it.
► Click on the SQL tab.
► In the text field write the following SQL query:
update users set pass=md5('NEWPASS') where uid = 1; where "NEWPASS" is your new Drupal administrative password.
Click the GO button to submit the query. If the query is executed correctly and no errors are displayed then you should be able to login with the new password.

A favicon (short for favorites icon), also known as a website icon or bookmark icon is a 16×16 pixel square icon that appears near the address bar and in the bookmarks folder in a visitor's browser. By default, a drupal site shows that water drop kinda drupal logo as favicon.

► Create your own favicon.ico file using any graphic tools or with the help of any online favicon generator tools like dnamicdrive.
► Navigate to admin » site building » themes and click the configure link next to your current theme. This will bring up the theme configuration page.
► Here you will see a section titled Shortcut icons settings. You can either upload your favicon file or specify the path to your customized icon file.
The changes may not appear immediately in your browser, you need to clear your browser's cache and reload the page. If you have bookmarked your site, you may need to delete the bookmark and then recreate it again so that the new favicon will appear in the bookmarks menu.

Drupal's default URL structure is like "http://www.sitename.com/?q=node/10″ This URL format can be hard to read, and can sometimes prevent search engines from indexing all your pages properly. In this case you can eliminate this "?q=" and clean the URLs through the following steps.
Navigate to Administer » Site configuration » Clean URLs. By default, it will be disabled. Select enabled and click the save configuration button. You are done.
You can make your URLs even more cleaner with the help of path module.
Home » Administer » Site building » Modules: enable the Path Module.

The Pathauto module automatically generates URL/path aliases for various kinds of content (nodes, taxonomy terms, users) without requiring the user to manually specify the path alias. This allows you to have URL aliases like /category/my-node-title instead of /node/123. The aliases are based upon a "pattern" system that uses tokens which the administrator can change.

To prevent the navigation block title or any other block title from appearing in the pages, just do the following.
► Navigate to Administer » Site building » Blocks and click the configure link next to the Navigation block.
► In the block configuration page, enter <none> in the Block title filed. This will override the default title for the block and remove the title.

The interface text (like the "Log in" button and the "Add new comment" text) is in English by default, but can be translated. For many languages, there are completed or partly completed translations available. (See the locale module on how to use them.)
All languages need more translation contributions. Some have only incomplete versions of the text in core, so that parts of the interface will show up in English. Others may be complete but need corrections and improvements of the language. And no language has a complete set of translations for all contributed modules.

Image module allows users with proper permissions to upload images into Drupal. Thumbnails and additional sizes are created automatically.
Images could be posted individually to the front page, included in stories or grouped in galleries.

Yeah it's possible! You can apply different themes to different pages in your drupal site simply with the help of a cool module called 'Sections'.

It's a fact of life that you'll have to upgrade your Drupal installation and contributed modules fairly frequently. Your candidate should mention:
► backing up the site,
► putting it into maintenance mode
► downloading the new version of the module
► uncompressing it
► running update.php
► testing the site
► taking the site out of maintenance mode
Ideally, your candidate would also mention creating a development environment to minimize downtime. There is also a big difference between upgrading a module (process described above) and a Drupal minor version upgrade, which requires more careful patching. Drupal major version upgrades, which happen every couple years, are another can of worms entirely.

Create a new page with some extra information, so that your visitors don't ever plunge on to the default boring 404 - page not found error page.
Once this page is created:
► Remember its node ID,
► Go to Administer > Site configuration > Error reporting
► Set Default 404 (not found) page to the node ID you just created
► Save your settings
You can also use the Search 404 module as an alternative.