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As Mark told an anecdote about Carol and Bob while the rst photograph was on the screen, it packed the image on screen with meaning. Here the jurors could connect emotionally with Bob and Carol, because anyone could relate to the details of their life together and be happy for them. But the emotion that had been attached to the rst slide was suddenly stripped away visually with the removal of the background in the second slide, signaling that something unexpected was about to happen. The third slide becomes deeply poignant when visually Carol is suddenly left alone, with only an empty outline de ning the space where her husband once was. Although the photo sequence is very simple, it had a deeply profound impact. When you think of writing and illustrating your Setting headline, consider how you can use a simple anecdote and photograph to quickly orient your own audience in an equally savvy way.winforms pdf 417 reader, winforms qr code reader, winforms upc-a reader, winforms data matrix reader, winforms gs1 128, winforms ean 13 reader, c# remove text from pdf, replace text in pdf c#, winforms code 39 reader, itextsharp remove text from pdf c#,
As well as being able to include code from other files, we ve looked at using modules (and their namespaces) to separate potentially clashing classes, methods, and constants into distinct groups Modules also provide a way to mix in functionality to other classes without using inheritance Ruby provides a wealth of useful libraries within the main distribution, but using tools such as RubyGems allows you to get access to code written by thousands of other Ruby developers, allowing you to implement more-complex programs more quickly than would otherwise be possible Let s reflect on the main concepts covered in this chapter: Project: Any collection of multiple files and subdirectories that form a single instance of a Ruby application or library require: A method that loads and processes the Ruby code from a separate file, including whatever classes, modules, methods, and constants are in that file into the current scope.
load is similar, but rather than performing the inclusion operation once, it reprocesses the code every time load is called Library: A collection of routines, classes, methods, and/or modules that provides a set of features that many other applications can use RubyGems: Packaging system for Ruby libraries and/or applications that makes them easier to install and maintain by developers Edge/source/development builds: Special versions of libraries and applications that aren t official releases, but reflect the latest work performed by the developers of the library or application However, with the popularity of test-driven development, many of these cutting-edge libraries are still reliable to use, though their most recently added features might not be fully documented or tested Gem: A single library (or application) packaged up using the RubyGems system Can also be called a RubyGem.
Before ending this chapter, I want to first tell you about yet another couple of ways of writing strings. These alternate string syntaxes can be useful when you have strings that span several lines, or that contain various special characters.
In an entertaining ctional story, the main character is someone an audience observes from a distance. But in a non ction BBP presentation, you write the Role statement in Act I to heighten the audience s interest by acknowledging their role here at the center
In many of the chapters from here on, we ll be using the power of libraries, and combining multiple libraries to make single applications One such example is the Ruby on Rails framework we ll be covering in 13, which is, in essence, a giant library made up of several libraries itself! In 16, we ll come back to RubyGems and look at some of the most useful gems available, their functions, and how to use them..
n this chapter we re going to look at the finer details of developing reliable programs: documentation, error handling, debugging, and testing. These tasks aren t what most people think of as development, but are as important to the overall process as general coding tasks. Without documenting, debugging, and testing your code, it s unlikely that anyone but you could work on the code with much success, and you run the risk of releasing faulty scripts and applications. This chapter demonstrates how to produce documentation, handle errors in your programs, test the efficiency of your code, and make sure that your code is (mostly) bug free, all using tools that come with Ruby.
In the previous section we looked at how exceptions work. When raised, exceptions halt the execution of the program and trace their way back up the stack to find some code that can handle them. If no handler for the exception is found, the program ceases execution and dies with an error message with information about the exception. However, in most situations, stopping a program because of a single error isn t necessary. The error might only be minor, or there might be an alternative option to try. Therefore, it s possible to handle exceptions. In Ruby, the rescue clause is used, along with begin and end, to define blocks of code to handle exceptions. For example: