It happens to the best of us, sometimes we commit something that just simply wasn't ready, or maybe we're having a bad day and introduced a bug to the code. I've even seen scenarios where you've created a temporary workaround in your codebase and now you're ready to remove that workaround and put in a real fix. This lesson looks at using the git revert command to deal with these scenarios by creating new commits that reverse the changes of a previous commit.

In this tutorial we're going to use the git bisect command to do a little bit of debugging. We're all human, and sometimes bugs get introduced our software and we may not notice them for a while. Especially on fast moving projects. A good example of this would be a performance regression, and now you want to figure out what commit made everything run slower all of a sudden. Bisect allows us to do a binary search between a known good commit and a known bad commit and quickly narrow down which commit introduced the problem. From there it's much easier to figure out what exactly the problem is and fix it.

GitHub is a great, free service that lets you share your Git repositories online with others. In this tutorial, Blake gives a quick tour of our Git Series Example GitHub project, and then explains how pull requests work, letting you merge changes into the repository through the UI. Feel free to try it out by adding jokes to our new jokes.txt file!

This tutorial takes a look at applying a patch from Drupal.org to your local copy of a module or Drupal core using Git. Afterwards we'll look at how you can create your own patches, using git diff and git format-patch, in order to contribute code back to Drupal or any of the module's on Drupal.org. You can see a full Git workflow using GitHub in the lesson Git Workflow: Putting It All Together.

Additional resources

Git Best Practices: Upgrading the Patch Process article
Applying a patch in a feature branch

In this tutorial, Joe walks you through a typical Git workflow. We start with cloning a repository, creating a branch, and getting some work done. Then we go ahead and commit our work, merge it into the master branch, and push our changes back up to the remote repository.

We've now learned about all sorts of commands in git and the flags that accompany those commands. We've also seen that some of those commands can get to be a bit long and are used quite often. In this lesson we're going to take a look at how to create command aliases in our .gitconfig file so that we can have a shorthand for accessing some of these more esoteric commands. We'll also take a quick tour of Joe's personal .gitconfig file that he uses in his day-to-day work.

Use the jQuery plugin system to extend the set of methods available in jQuery beyond those provided by the core jQuery library. See where to find jQuery plugins, and examine a number of the available plugins and when to use them and what to use them for. See how to make use of plugins in your custom jQuery code. Finally, learn how to write your own plugins to extend the basic jQuery functionality.

A brief summary of the material covered in the Introduction to jQuery video series

This video shows you how to create your own custom shortcuts for various commands. We'll look at some common aliases and see how to add them to our command line environment. This is super handy for commands that you type in all the time and don't want to go through the tedium of typing the whole thing out every time. For example, we show how to automatically go to a particular directory with just one word (e.g. type "clients" and go to the /Users/add1sun/lullabot/clients directory immediately).

Overview the Firebug extension for Firefox and how it can be used to aid in the development of Javascript. Real time development and debugging of Javascript.

Learn about using jQuery to apply animation and effects to DOM elements. Show and hide things on the page using the fade, slide, and hide/show methods. Chain multiple effects together to create animations. And use the jQuery .animate() function to preform more complex animations.

Learn how to respond to the actions that a user performs on a page using jQuery events. Attach event handlers to DOM elements and respond to mouse events like click and hover, and keyboard events such as someone pressing or releasing a key. Finally learn about responding to special events that only occur on form elements. This chapter gives a description of each of the available jQuery events and how or when they are triggered. Check out http://quirksmode.org/js/keys.html for more information on compatibility for assigning keyboard events across multiple browsers.

Add a jQuery Javascript file to Drupal following best practice methods for including javascript files on the page. Learn about how your custom jQuery scripts are loaded on to the page, and when they get executed. Introduces jQuery's no-conflict mode and provides some best practice examples for writing your own jQuery files within the context of Drupal as a whole.

Note: To avoid hiding all blocks on your page, target your blocks more specifically. For example, #sidebar .block .content Also, inspect your markup for the existence of a class of title on the h3, which may or may not be applied in your theme. The new example below does not include the title class.

(function($){
  $(document).ready(function(){
    
    $('#sidebar .block .content').hide();
    $('#sidebar .block h3').css('cursor', 'pointer').click(function(){
      $(this).parent().children('.content').slideToggle();
    });

  });
})(jQuery);

Use jQuery to manipulate DOM elements including adding and removing classes to an HTML element, changing the content of an element, wrap a set of elements with a new element, adding new elements to the page using prepend and append methods and the related prependTo and appendTo methods. Use jQuery to manipulate properties height, width, and position of any DOM element. Finally learn how to use jQuery to completely remove selected DOM elements from the page.

Traverse the DOM tree using jQuery to find the children, parents, and other nearby elements of any selected element on the page. Learn how to select an element up the page and reliably locate it's siblings by traversing up the DOM to a parent element and then back down using find. Use additional jQuery methods to filter a list of DOM elements down using find to apply an additional selector to the list, not to filter out elements that do not match a set of criteria and more.

This video looks at the basics of working with MySQL from the command line. We get into the mysql environment and look at databases, tables and fields. We cover creating and deleting databases, creating a user, and querying within a particular database.

Note: In some places the command line prompt is cut-off. The YouTube version of this video doesn't have the cut-off problem. We are working on getting this fixed, but in the meantime, check out the YouTube version instead.

Command Line Basics 13: Using MySQL from Command Line (youtube.com)

This is an introduction to the Tail command, available on Unix/Linux systems. Tail has many applications, but this video concentrates on its basic usage and useful options, as they pertain to Drupal developers.

You'll learn how to take a quick peek at recent log messages from a single log file, how to do the same thing with multiple logs, as well as watching log files in real time! We'll finish up with a practical application, to see why this is useful.

Commands used in this video:

To view the documentation (or manual) for the tail command:
man tail

To show the last 20 lines of the webserver's access log file:
tail /var/log/apache2/access.log

To show the last 20 lines of the webserver's error log file:
tail /var/log/apache2/error.log

To show the last 20 lines of the webserver's error log file and continue to print new lines added to the file:
tail -f /var/log/apache2/access.log

In this tutorial, I'll introduce the API Blueprint specification and take a look at a few tools we can use to provide documentation and testing for our API.

The tools we'll look at include:

• Apiary
• API Blueprint
• Dredd
• Aglio

By the end of the tutorial you'll have a better understanding of the API Blueprint specification and be able to use Dredd and Aglio to ensure your API documentation and testing stay up-to-date.

Self-check question: Could you write a script that could be run after every commit that would keep your documentation up-to-date, and provide API test results?

Additional resources

Apiary
API Blueprint
Dredd
Aglio