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Ruby on Rails: Up and. Running is more than a complete catalog of O'Reilly books. You'll also find links to news, events. The first edition of Programming Ruby was such a book; the second edition is even The best way to learn to think the Ruby way is to read Programming Ruby . The Little Book Of Ruby is a PDF eBook which will guide you through the fundamentals of Ruby programming. Starting with the basics (strings, numbers, objects.

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PDF Drive is your search engine for PDF files. As of today we have Books and '' Michael Hartl's Rails Tutorial book is the #1 (and only Ruby on Rails. Getting started with Ruby Language, Casting (type conversion), Operators, Variable If you found this Ruby® programming book useful, Download PDF Book. Welcome to Learn Ruby the Hard Way, 3rd Edition. You can visit the companion site to the book at where you can Zed A. Shaw, you'll get a professional quality PDF and hours of HD Video, all DRM-free and.

The structure of the book is that of a patterns catalog. But these are not large, heavy-weight architectural patterns. These patterns are small, most of them taking place at the level of an individual method or even a single line of code. They are related by a single organizing principle: removing the uncertainty that leads to code constantly second-guessing itself; and replacing it with a confident, clear focus on the task at hand. How to streamline your code and eliminate repetitive conditionals with the Special Case and Null Object patterns… and how to avoid the gotchas that can come with naive implementations of these patterns. How to make your methods more flexible by passing in behavior instead of data. An applied demonstration of refactoring two Open-Source Ruby projects using patterns from the book.

The Rails API gives us additional classes that are useful for web applications. Learning the syntax of Ruby code gets you started with Ruby programming; knowing the API classes leads to mastery of Ruby. It is described in the Ruby API reference documentation.

The Date class has a Date. You can see this syntax when we assign Date. The Date. Imagine a September birthday. You must use Date. If you enter a date in the format Date.

When the Date. The Date class can perform complex calendar arithmetic. The variables birthdate and today are instances of the Date class. The if Then we subtract today from birthday. This shows you the power of programming in Ruby. Notice that I needed 16 paragraphs and over words to explain 15 short lines of code. But without knowing more than this, we can build a simple web application.

View The Owner model provides the data we want to see on the Home page. In a typical application, one controller can render multiple views, so we make a folder to match each controller. Or use the Unix mkdir command: Some experi- enced developers prefer to add gems that provide the Haml or Slim templating engines. As you might guess, a View that uses the Haml templating syntax would be named new. This markup allows us to insert Ruby code which will be replaced by the result of evaluating the code.

You may have noticed that we refer to the Owner model with the variable owner. It will be clear when we create the Visitors controller why we use this syntax a variable name that begins with the character is called an in- stance variable.

The Rails implementation becomes useful if the name is retrieved from a database or created programmatically. There is no way to display a calculation using only static HTML, so Rails gives us a way to display the birthday countdown calculation. Controller The Visitors controller is the glue that binds the Owner model with the Visi- torsController new view. In this context, the character is only a documentation con- vention. The class name is written in camelCase with a hump in the middle, like a camel so we can combine two words without a space.

We create an instance variable named owner and assign an instance of the Owner model. Keep in mind the purpose of the controller. Each controller action method responds to a request by obtaining a model if data is needed and rendering a view.

The new method is deceptively simple. Hidden behavior inherited from the ApplicationController does all the work of rendering the view. We can make the hidden code explicit if we wish to. It would look something like this: Rails often offers default behavior that looks like magic because the underlying implementation is hidden in the depths of the Rails code library. Revealing the hidden code, we see that invoking the new method calls a render method supplied by the ApplicationController parent class.

The code underlying the render method is complex. Rails takes care of the rest. As you gain experience, you can dive into the Rails source code to unravel the magic. Scaffolding This tutorial aims to give you a solid foundation in basic concepts. The model— view—controller pattern is one of the most important. For example, Rails Guides: Students often use scaffolding to create simple Rails applications. Enter the command: Dynamic home page shows days until a birthday.

And the underlying code conforms to the conventions and structure of Rails. Git At this point, you might have the Rails server running in your console window. You might think you have to enter Control-c to shut down the server and get the command prompt.

You can open more than one console window. Your terminal application lets you open multiple tabs so you can easily switch between windows without using a lot of screen real estate. It is convenient to have a console window open for the server and another for various Unix commands. Before we do any more work on our tutorial application, we need to learn about troubleshooting and debugging.

Use the git status command to check: Interactive Ruby Shell There will be times when you want to try a snippet of Ruby code just to see if it works. IRB is a Ruby interpreter that runs from the command line. It executes any Ruby code and provides an immediate response, allowing you to experiment in real-time.

If you enter a valid Ruby expres- sion, the interpreter will display the result of evaluating the expression. Try simple arithmetic: You are using your computer for simple math.

Maybe you can delete the calculator app from your phone. IRB will evaluate any Ruby expression and helps you quickly determine if syntax and logic is correct. Actually, IRB can handle multiple lines of code. Try it: Pry is a powerful alternative to the standard IRB shell for Ruby. As you gain experience, you might take a look at Pry to see what the enthusiasm is all about. Your application will be running as if the application was waiting to respond to a web request.

Then you can expose behavior of any pieces of the web application.

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Loading development environment Rails 4. The prompt shows it is ready to evaluate an expression. Then we can use the Owner. Each instance is a unique object with its own data attributes but the same behavior as other objects in- stantiated from its class.

The bits that were organized to create the variable name will evaporate into the ether. Enter Control-d or type exit to quit the Rails console. The Rails console is a useful utility. It is like a handy calculator for your code. Use it when you need to experiment or try out short code snippets. Rails Logger As you know, a Rails application sends output to the browser that makes a web request.

On every request, it also sends diagnostic output to the server log file. Scrolling the console win- dow is a good way to see diagnostics for every request. You can add your own messages to the log output by using the Rails logger. You could see how the application behaves, step by step. The Rails logger is the best tool for the job. In a controller, you can use the method logger on its own. In a model, you have to write Rails.

You can use any of the methods logger. Log messages written with the logger. If you want your log messages to stand out, you can add formating code for color: Debugging Rails Appli- cations.

Revisiting the Request-Response Cycle Earlier, when we investigated the request-response cycle, we looked in the server log to see the response to the web browser request. We can see evidence of the model-view-controller architecture.

Our debug statements show we enter the new method and reveal the value of the Owner name. As we learned, the model-view-controller architecture is an abstract design pat- tern. Now we can see it as activity in the server log. Error page. In the console log, the stack trace will show everything that happens before Rails encounters the error: There are times when it pays to carefully read through the stack trace line by line, but most often, only the top line of the stack trace is important. The point of this exercise is to encourage you to read the top line of the stack trace and use it to diagnose the problem.

However, there is a better way to force your program to halt, called raising an exception. Rails includes various exception handlers to display errors in production so users will see a helpful web page explaining the error.

Check the status to make sure: By all means, if you love the precision and order of programming languages, dive into the study of Ruby from the beginning. Reading Knowledge of Ruby What you need, more than anything, when you start working with Rails, is reading knowledge of Ruby. It will not be a model, view, controller, or any other standard component of Rails.

The jaws that bite, the claws that catch! Beware the Jubjub bird, and shun The frumious Bandersnatch! But it is unclear how the author intends anyone to use the code.

In this case, I just want to give you some code that illustrates typical Ruby syntax and structure. Code is only strings of characters. But some strings have special meaning for everyone and all others are arbitrary words that only have meaning to an individual developer. Some made-up words will be obvious because they are just too idiosyncratic to be part of the Ruby language. There is only one way to be sure which words are part of the Ruby language: Check the Ruby API.

You can use IRB to try out the example code in the console. The ex. Remember you can use Control-d to exit from IRB. Whitespace and Line Endings Whitespace characters such as spaces and tabs are generally ignored in Ruby code, except when they are included in strings.

Some programming languages Java and the C family require a semicolon as a terminator character at the end of statements. Ruby does not require a semicolon to terminate a statement. Comments Ruby ignores everything that is marked as a comment. Use comments for notes to yourself or other programmers. This is a comment. Code must exactly follow the syntax of a lan- guage. Typos, guesses, and code that is almost-but-not-quite right will simply fail, often without any helpful error messages.

Computers seem intelligent because they can execute code conditionally. You can write a program so that given one set of conditions, certain parts of the code will execute, and given different conditions, other parts of the code will execute. Lastly, programs are written to transform abstractions from one form to another. When we learn simple arith- metic, we learn we can take the symbols for numbers and add them together to make a different number.

Computer programs do more than add numbers; a program can transform words and other abstractions. Assignment In Ruby, like many other programming languages, the equals sign indicates we are assigning a value. The equals sign is the assignment operator. And name is a variable that stores the value so it can be easily reused. Just as we can assign a value to a variable, we can reassign a new value when- ever we want. That is why we call them variables; the value can vary.

Foobar Kadigan' Variables can be assigned strings of letters, numbers, or anything else. Object-Oriented Terminology Software architects use a common vocabulary to talk about programming lan- guages: You can write code and intuitively grasp the meanings. Or you can gain an understanding by applying metaphors.

Houses For example, some programming textbooks attempt to explain a class like this: A blueprint for a house design is like a class definition. All the houses built from that blueprint are objects of a class we could call House. Vehicles Or: Vehicles can have attributes, like color or number of doors. They have behavior, or methods, like buttons that turn on lights or honk a horn.

A class definition is like a cookie cutter. Bits in the computer memory are like cookie dough. The cookie cutter makes as many individual cookies as you want. Each cookie is an instance of the Cookie class, with the same shape and size as the others. Cookies are objects.

You can decorate each cookie with sprinkles, which are attributes that are unique to each instance. Running a program is like baking. The cookies change state from raw to cooked. Sticking a toothpick in a cookie is like calling a method.

The method returns a result that tells you about the state: Is it done? Limitations of Metaphors Metaphors are imperfect. If baking was like running a program, all the cookies would disappear as soon as the oven was turned off. What values are possible for the attribute Gender?

For many years, Facebook offered two choices, male and female.

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As Sarah Mei discusses in a blog post, Why Gender is a Text Field on Diaspora, your assumptions have conse- quences when you build a model. They typically represent an abstraction, like an Array or a Hash, which inherits char- acteristics from another abstraction, for example, a Collection.

Terminology such as class and instance describe the abstrac- tions and the relationships among them. For the software architect, classes make it possible to create a structure for complex software programs. There is one class at the apex of the Ruby class hierarchy: BasicObject is a very simple class, with almost no methods of its own. The Object class inherits from BasicObject.

Object provides basic methods such as nil? The example just shows it for teaching purposes. Here is the Example class without the explicit subclassing from Object: Methods get the work done.

Any class can have methods. Methods are a series of expressions that return a result a value. We say methods describe the class behavior.

Here we will return the string assigned to the variable name. This example shows how you can override any method inherited from a parent class. This tiny punctuation symbol is a powerful operator in Ruby. It allows us to call a method to get a result.

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Sometimes we say we send a message to the object when we invoke a method, implying the object will send a result. For example, you can run this in the Rails console: For example: For example, String has methods reverse and upcase among many others. We could write: These characters are simply a naming con- vention for Ruby methods. The question mark indicates the method will return a boolean value true or false.

In Rails an excla- mation point often means the method will throw an exception on failure rather than failing silently. Initialize Method Objects are created from classes before they are used. When we call the new method, we press the cookie cutter into the dough and get a new object. All the cookies will have the same shape but they can be decorated differently, by sprinkling attributes of different values.

The initialize method is one of the ways we sprinkle attributes on our cookie. The new method calls the initialize method automatically. Method Parameters Methods are useful when they operate on data. Parameters are placeholders for data values. The values that are passed to a method are arguments.

Our initialize method takes name and date arguments: We separate our parameters with commas. For readability, we enclose our list of parameters in parentheses. In Ruby, parentheses are always optional but they often improve readability.

We can assign any object to a variable. The variable works like an alias.

We can use a variable anywhere as if it were the assigned object. The variable can be assigned a string, a numeric value, or an instance of any class all are objects.

You can assign a different kind of object if you want. Symbol Obviously, we see many symbols when we read Ruby code, such as punctua- tion marks and alphanumeric characters. It is like a variable, but it can only be assigned a value once. After the initial assignment, it is immutable; it cannot be changed.

We can use the initialize method to input data to the object. Attributes are a convenient way to push data to an object and pull it out later.

In Ruby, attributes are also called properties. For example, we could write: Instance Variable Inside an object, an ordinary variable only can be used within the method in which it appears. The scope of a variable is limited to the method in which it is used. Often you want a variable to be available throughout an instance, within any method. The instance variable can be used by any method after the class is instantiated. If you create multiple instances of a class, each will have its own values for its instance variables.

Here we create two instances of the Example class. We use an instance variable when we want a model to be available to the view template. Rails beginners learn the simple rule that you have to use the at sign if you want a variable to be available in the view.

That leads to a question: Why is an instance variable available inside a view? There is a good reason. A Rails view is NOT a separate class. It is a tem- plate and, under the hood, it is part of the current controller object. This example shows us that the programmer and the software architect have different perspectives on a Rails application.

Understanding Rails requires an integration of multiple points of view. In this case, we only assign a value to the variable if no value has been previously assigned. Conditional Conditional logic is fundamental to programming. Our code is always a path with many branches. If the expression is true, the statements following the condition are executed. If the expression is false, any statements are ignored, unless there is an else, in which case an alternative is executed.

Or if can be followed by a variable that has been assigned a boolean value.

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Or you can call a method that returns a boolean result. If date is already assigned a value, we assign it to the instance variable date. Ruby developers like to keep their code tight and compact. This compact conditional syntax is named the ternary operator because it has three components. Here is the syntax: For more Ruby code that has been condensed into obscurity, see an article on Ruby Golf.

Ruby golf is the sport of writing code that uses as few characters as possible. We already know that we can assign a string to a variable: Foobar Kadigan" Single quote marks indicate a string. In the example above, we enclose a space character within quote marks so we add a space to our string.

You can eliminate the ungainly mix of plus signs, single quote marks, and space characters in the example above. Use double quote marks and you can perform interpolation, which gives a new job to the hashmark and curly brace characters: Foobar Kadigan" The hashmark indicates any expression within the curly braces is to be evalu- ated and returned as a string.

This only works when you surround the expres- sion with double quote marks. Sometimes you want to create a method that only can be used by other methods in the same class. This is common when you need a simple utility method that is used by several other methods. Any methods that follow the keyword private should only be used by meth- ods in the same class or a subclass.

Ruby provides a protected keyword as well, but the difference between protected and private is subtle and protected is seldom seen in Rails applications. Computers have always been calculation machines; they are just as important in managing collections. One important type of collection is named a Hash. A Hash is a data structure that associates a key to some value.

You retrieve the value based upon its key. This construct is called a dictionary, an associative array, or a map in other languages. Ruby 1. In a Hash, a trailing colon makes a string into a symbol.

If you want to transform a string containing spaces into a symbol in a Hash, you can do it, though the syntax is awkward: Arrays can hold objects of any data type. In fact, arrays can contain a mix of different objects. For example, an array can contain a string and another array this is an example of a nested array. An array can be instantiated with square brackets: See the Ruby API for a full list. Iterator Of all the methods available for a Ruby collection such as Hash or Array, the iterator may be the most useful.

Each item in an Ar- ray, or key-value pair in a Hash, is passed to the block of code to be processed. Block You can recognize a block in Ruby when you see a do A block is a common way to process each item when an iterator such as each is applied to a Hash or Array.

The block is like an unnamed method. The two variables are available only within the block. As each key-value pair is presented by the iterator, the vari- ables are assigned, and the statements in the block are executed. Computer scientists consider a block to be a programming language construct called a closure. Ruby has other closures, including the proc short for proce- dure and the lambda.

They are more common in the Rails source code where advanced programming techniques are used more frequently. The key point to know about a block or a proc or a lambda is that it works like a method. The example code only uses keywords from the Ruby API. Rails has its own API, with hundreds of classes and methods. We say Ruby is a general-purpose language because it can be used for any- thing. Ruby is a great language to use for building a DSL, which is why it was used for Rails.

Unlike some other programming languages, Ruby eas- ily can be extended or tweaked. Software archi- tects call this metaprogramming which simply means clever programming that twists and reworks the programming language. Some of the most powerful gems add their own DSLs to your project.

For example, the Cucumber gem provides a DSL for turning user stories into automated tests. Adding Rails, additional gems, and DSLs provides powerful functionality at the cost of complexity. But it all conforms to the syntax of the Ruby language. Spend time with a Ruby textbook or interactive course when you work on Rails projects. No more fooling around. With the next chapter, we start building a real-world Rails website.

Ruby on Rails Tutorial

Chapter 16 Layout and Views In previous chapters we created a dynamic home page and learned techniques for troubleshooting. This chapter covers a lot of ground, so take a break before jumping in, or pace yourself to absorb it all.

The Ruby code will be processed by a templating engine built into Rails. The output will be pure HTML sent to the browser. That is added by Rails to support turbolinks, for faster loading of webpages.

For the most part, everything is ordinary HTML. Where did all the extra HTML come from? The default application layout is where you put HTML that you want to include on every page of your website. Remember when we looked at the hidden code in the controller that renders a view? YIELD Alternatively, you could tell the controller to render the view without any ap- plication layout: The reference RailsGuides: Layouts and Rendering in Rails explains more about using alternative layouts.

Notice that the default application layout contains the Ruby keyword yield. The content from the view is inserted where you place the yield keyword. For example, you could create an application layout that includes a sidebar. The example above will create three list items, like this: Ruby is an ideal choice for a web application development platform such as Rails because it can easily be used to create a domain-specific language or DSL. We can add new keywords that produce complex behaviour, creating entire new APIs such as Rails.

It turns out that almost any website that accepts user input via a form is vulnerable to a security bug an exploit named a cross-site request forgery.

Rails provides a number of similar features that make websites more secure. Strange new keywords may be part of the Rails API. Think of it this way: But they serve as shortcuts to produce complex snippets of HTML and content. The Rails default starter application, which we get when we run rails new, provides a barebones application layout.

Rails provides the rails generate command to run simple scripts that are packaged into gems. Viewport The viewport metatag improves the presentation of web pages on mobile devices. The tag is required for either Bootstrap or Zurb Foundation front-end frameworks.

The viewport metatag looks like this: That means adding title and description metatags. Google uses contents of the title tag to display titles in search results. And it will sometimes use the content of a description metatag in search results snip- pets. Good titles and descriptions improve clickthrough from Google searches. Title and description looks like this: It uses the Ruby ternary operator which maximizes compactness at the price of intro- ducing obscurity.

The Rails asset pipeline utility is one of the most powerful features of the plat- form. It offers convenience to the developer and helps organize an applica- tion; more importantly, it improves the speed and responsiveness of any com- plex website. With multiple stylesheets, the HEAD section of your application layout might look like this: Instead, use the asset pipeline and simplify this. Assets With Rails The asset pipeline consists of two folders: Navigation Links Every website needs navigation links.

This is advantageous if we make changes to the location of the link destinations. Some webmasters like to use absolute URLs, specifying a host name in the link, for example http: We include the navigation partial in our application layout with the expression: The second parameter is the route. For now, we have nothing to add. Flash Messages Rails provides a standard convention to display alerts including error mes- sages and other notices including success messages , called a flash message.

Ac- tion Controller Overview. Flash message in Rails. When the page is reloaded or another page is visited, the message disappears. Creating Flash Messages Flash messages are created in a controller. We can assign other messages, such as flash[: In practice, Rails uses only: Use flash.

With flash. If you use flash. If you use the simple flash directive before a render directive, the message will appear on the rendered page and reappear on a subsequent page after the user clicks a link. In our example above, we really need to use the flash. The flash object is a Ruby hash. Hash is a type of collection. Because we have a collection with possibly multi- ple messages, we need to retrieve each message one at a time.

We learned earlier that all collections support an iterator method named each. Iterators return all the elements of a collection, one after the other. The iterator returns each key-value pair, item by item, to a block. You can add any code to a block to process each item from the collection. The output string will appear as HTML like this: The Flash Messages Partial Flash messages are a very useful feature for a dynamic website.

First, the expression if msg. String serves as a test to make sure we only display mes- sages that are strings. These elements are not unique to a Rails application and will be familiar to anyone who has done front-end development.

Notice the main tag: It typically contains links to copyright infor- mation, legal disclaimers, or contact information. Application Layout Our application layout is complete. Finally we have HTML5 structural elements. For more on CSS, there are thousands of tutorials on the web, but I like these: For now, the simple. The web server may already be running.

If not, enter the command: A website front end is all the code that runs in the browser. Everything that controls the appearance of the website in the browser is the responsibility of a front-end developer, including page layout, CSS stylesheets, and JavaScript code. Front-end development has grown increasingly important as websites have be- come more sophisticated. And front-end technology has grown increasingly complex, to the degree that front-end development has become a job for spe- cialists.

Front-end developers are primarily concerned with: Around the time that Rails became popular, front-end developers at large companies began to share best practices and establish open source projects to bring structure and consistency to front-end development, leading to development of CSS frameworks. Engineers at Yahoo! There are dozens of CSS frameworks. In general, they all seek to implement a common set of requirements: JavaScript Libraries and Frameworks JavaScript has nothing like RubyGems, a built-in package manager for code libraries, so initially there were few open source JavaScript libraries.

Now there are several competing JavaScript package managers and many software libraries. MooTools, Dojo, and jQuery soon followed. Of these libraries, jQuery has be- come the most popular, largely because of thousands of modular jQuery plug- ins that implement a wide range of effects and widgets web page features. These plug-ins are used to add visual effects and interactivity to web pages. Examples are drop-down menus, modal windows, tabbed panels, autocomple- tion search forms, and sliders or carousels for images.

Even without plugins, jQuery is useful as a high-level interface for manipulating the browser DOM document object model , to make it easy to do things like hiding or revealing HTML elements on a page. Any Rails application can use jQuery because it is included by default in any new Rails application. Libraries such as jQuery add functionality to server-side applications, such as those built with Rails. All use a variant of the model-view-controller MVC software design pattern to implement single-page applications which function more like desktop or mobile applications than websites.

None of these JavaScript frameworks dominate web application development like Ruby on Rails, but they are gaining popularity for single-page applications. Em- ber.

Unlike AngularJS or Ember. Combining CSS and JavaScript libraries in a common framework makes it possible to standardize and reuse common web page features. There are many responsive front-end frameworks to choose from, including: Each adds a library of markup, styles, and standard- ized web page features such as modal windows, pagination, breadcrumbs, and navigation. Bootstrap is the best-known front-end framework.

It is the result of an effort to document and share common design patterns and assets across projects at Twitter, released as an open source project in August Zurb Foundation was released as an open source project in October , after more than a year of internal use at Zurb, a Silicon Valley design consultancy. As a result, CSS rules are ver- bose and often repetitive. As a result, your stylesheets can use variables, mixins, and nesting of CSS rules, just like a real programming language.

Mixins are like variables that let you use snippets of reusable CSS. Nesting eliminates repetition by layering CSS selectors. Bootstrap or Zurb Foundation? Which should you use, Bootstrap or Zurb Foundation? Zurb Foundation has a solid following among Rails developers. It gained an initial advantage because Zurb provides a gem that adds Foundation to Rails.

When Zurb releases new versions of Foundation, the company updates the gem immediately. Recently in January , the Bootstrap team started supporting a Ruby gem that provides a drop-in Sass version of Bootstrap for Rails.

Now any preference for Foundation over Bootstrap is primarily a matter of personal taste. Bootstrap has a larger developer community and more third-party projects, as evidenced by a Big Badass List of Useful Twitter Bootstrap Resources. In its sheer magnitude, this list, from Michael Buckbee and Bootstrap Hero, demon- strates the popularity of Bootstrap and the vitality of its open source commu- nity.

Graphic Design Options There are three approaches to graphic design for your Rails application. Consequently, sites that use Bootstrap or Zurb Foundation look very similar. A third option is to download a pre-designed theme for your website. You may have visited ThemeForest or other theme galleries that offer pre-built themes for a few dollars each. Take a look at some of the inexpensive themes for Foundation that you can adapt for Rails: The site Themes for Bootstrap aggregates Bootstrap themes, or you can visit sites such as Start Bootstrap, Bootswatch, or the Themestrap gallery.

Zurb Foundation Gem Zurb Foundation provides a standard grid for layout plus dozens of reusable components for common page elements such as navigation, forms, and buttons.

More importantly, it gives CSS the kind of structure and convention that makes Rails popular for back-end development. Zurb Foundation is packaged as a gem.

Our approach is slightly different from the Zurb in- structions but yields the same results. Note the. This will allow you to use the advantages of an improved syntax for your ap- plication stylesheet.

You learned earlier that stylesheets can use variables, mixins, and nesting of CSS rules when you use Sass. Sass has two syntaxes. The Sass project also offers a second, older syntax with indented formatting that uses the extension.

The asset pipeline will preprocess any. The application. Your CSS stylesheets get concatenated and compacted for delivery to the browser when you add them to this directory: If you are familiar with CSS syntax, it may seem odd that the relevant lines are commented out using asterisks. Though they are com- mented out, the Rails asset pipeline reads and understands them. However, in practice, you are more likely to modify the style rules provided by Zurb Foundation. How you organize your CSS is up to you; the asset pipeline lets you organize your CSS so it is easier to develop and maintain.

In general, only large and complex sites need this optimization. Like the application. Here are just a few examples: These are building blocks you use for page layout and typographic styling. For example, Foundation gives you CSS classes to set up rows and columns in a grid system. The layout will change at each breakpoint. The grid gives you 12 columns by default. You can organize your layout in horizontal and vertical sections using row and columns classes.

For example, you could use Foundation grid classes to set up an application layout with a footer as a row with two sections: The footer will con- tain two side-by-side sections.

On phones, each section will expand to take the full browser width, appearing as stacked rows. To better understand the grid system with all its options, see the documentation for the Foundation Grid. Presentational Versus Semantic Styles There are two schools of thought among front-end developers.

For these developers, the Foundation classes are both practical and descriptive, making it easy for any developer who knows the Foundation framework to visualize the layout of a page. In an ideal world, all markup would be semantic, with class names describing the function or purpose of a style.

For example, a submit button often needs styling. Compare these two approaches to markup: Using Foundation Classes Directly Foundation often mixes presentational and semantic markup.

For example, you can style a button like this: For example, the Foundation grid system is presentational. Specifying rows and columns, and quantifying the size of columns, describes the visual appear- ance of sections of the layout rather than the purpose of each section. The pre- sentational approach makes it easy to visualize the layout of a page. If class names change in Foundation 6.

Is it worth the effort to add the complexity of Sass mixins just to future-proof your website? Probably not for a simple website such as the one you are build- ing for Foobar Kadigan.

It will probably be very similar. Then we use mixins to create semantic classes. The second declaration mixin six-columns-centered makes a column that is six columns wide with centered text.

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Next we create a few classes that use the mixins or combine Foundation CSS classes. For example, the new submit class can be used for a rounded button. We use the include directive to add the mixins we need. We also use the extend directive to add a Foundation CSS class. And we di- rectly set CSS properties such as background-color and margin-top. For a simple website, this could be over-engineering and counter-productive.

The Modernizr JavaScript library is a prerequisite for Foundation. Modernizr makes it possible for older browsers to use HTML5 elements. It also detects mobile devices. But if you read it, you will understand a little more about the mysteries of the Rails asset pipeline. It adds: For Foundation 5 config. And by the way, the. For now, you can forget you learned this. The expression if msg. String serves as a test to make sure we only display messages that are strings.

We construct a div that applies Foundation CSS styling around the message. Foun- dation recognizes a class alert-box and round for rounded corners.

Rails notice messages will get styled with the Foundation success class. Any other Rails messages, including alert messages, will get styled with the Foundation alert class.

Best Books to Learn Ruby

Foundation provides detailed documentation if you want to change the styling of the alert boxes. The navigation menu is a great demonstration of the ability of Zurb Foundation to adjust to the small screen size of a tablet or smartphone.

The enclosing layout is used to generate the navigation menu when the browser window shrinks to accommodate a tablet or smartphone. The navigation links partial will be simply a list of navigation links. By separating the links from the styling that creates the navigation bar, we segregate the code that is unique to Zurb Foundation. In the future, if the Zurb Foundation layout or CSS classes change, we can make changes without touching the navigation links. If we wish, we can replace the navigation partial and substitute one that uses Bootstrap styles instead of Foundation, leaving the navigation links intact.

We could set up styling for the form when we implement the contact page, but it is convenient to set up form styling now, as we would if we were adding multiple forms to the site. Rails provides a set of view helpers for forms. They are described in the RailsGuides: Rails Form Helpers document. The Simple- Form helpers are more powerful, easier to use, and offer an option for styling with Zurb Foundation.

Run the generator to install SimpleForm with a Zurb Foundation option: You should see a new page design that displays Zurb Foundation styling.

There are three types of web pages in a Rails application. It has static content; that is, no dynamic data is needed on the page. But it uses the default application layout to maintain consistency in the website look and feel.

We classify this type of page as a: Alternatively, a dynamic page can be created that has no model, a nearly-empty controller, and a view that contains no instance variables. This solution is quite common for static views that use the application layout. This solution is implemented so frequently that many developers create a gem to encapsulate the functionality.

We also will create a Contact page. The High Voltage gem contains all the controller and routing magic required for this to happen. While in service, he invented the kanuten valve used in the processing of unobtainium for industrial use.

With a partner, Granda Fairbook, he founded Acme Manufacturing, later acquired by the Advent Corporation, to develop his discovery for use in the Turboencabulator. This list has shortlisted some tutorials that will help beginners in ruby programming.

Video tutorials, which can be downloaded from the internet for free, are the best way in which you can learn every aspect of the Ruby language, without wasting a lot of time. There are video tutorials for beginners as well as advanced users. Making use of an online website is one of the best ways in which you can learn ruby programming in a fun and interactive manner. You will come across plenty of manuals, references, and tutorials which will come to your rescue when you will start using the language.

Ruby tutorials by Tutorial Point Ruby Tutorial: There are many books on Ruby programming language which are present in the downloadable form.

Most of these books are very interactive and engrossing with straightforward and easy to understand language. Neighborly's Humble Little Ruby Book. The Ruby Rails online web forums give you an opportunity to interact with experts, from all across the globe, by asking questions and sharing your own knowledge.

Ruby community is full of excellent and expert bloggers. These blogs can help you stay up to date with latest trends and best practices. Once you are in the process of working with Ruby programming language, it may happen that you forget something and require a quick reference. This is where cheat sheets will come into the picture which can be used as a simpler set of notes.