In its short history, jQuery has revolutionized front-end web development, making it faster, easier, and more rewarding to write JavaScript – allowing easier selection and manipulation of HTML elements, and ensuring that scripts work across the ever increasing landscape of browsers and operating systems.
Nate Haug and Jeff Robbins show many hands-on examples demonstrating how to use jQuery's simple syntax to choose and manipulate HTML elements, traverse the document object model (DOM), and to attach event handlers which can react to user interaction with the page.
In this video, Jeff and Nate introduce themselves and the agenda for this series, including Selectors, Effects, and AJAX.
Just like PHP or JavaScript, Twig has functions that can be used once we’re inside either a Twig delimiter. To see the built-in functions, check out the bottom of the Twig documentation page. In your application, especially if you’re using Twig inside something like Symfony or Drupal, you may have even more functions available to you. Fortunately, the syntax to use a function is always the same: just check out your project’s documentation to see what other goodies you have. In this tutorial, you will start using Twig functions and filters to get the length of a collection in our demo site. We'll also play around with the dump
function to see how we can go about debugging Twig.
Additional resources
Until now, we’ve been working with simple values like pageTitle or products, which is an array that contains simple values where we loop over and print each out. In this tutorial, you will work with more complicated arrays, using keys, and figure out how to get at object data as well.
If we view the HTML source of our project so far, we’ll see just the HTML tags and printed variables from our homepage.twig file
. So far, there’s no HTML layout, head or body tags, but since our project has been ugly long enough, in this tutorial we'll add these. Instead of just putting these in our homepage file, we're going to make this more flexible by using template inheritance, so we can reuse these pieces in other template files as we grow our site. We'll be diving into the world of Twig extends and blocks, and talking about how to avoid common mistakes.
Additional resources
Using a base layout is very common, and we’ve implemented that in the previous tutorial. Sometimes you also need to include some other templates on only select pages. In this tutorial you are going to add a sales banner to the pages using the include
function, and working with the variables we can pass there.
Additional resources
Be sure to check the documentation for the version of Twig in your codebase for the correct syntax and usage.
In our last tutorial we have things set up to include a new template, but we are currently getting an error, due to not passing the correct variable. In this tutorial we'll see how to fix this problem by adding a "defined" test to our code, which will check to see if the variable is defined in the _banner.twig template
, and default to "lightblue" if it is not.
Additional resources
Our products are printing out a bit weird right now because they’re floating, but not breaking correctly. To fix this, we need to wrap every three products in their very own row. In this tutorial, you will use a "divisibleby" test to see if the item number we’re on is divisible by three, and then loop through them. We'll also clean up our if
statement for our background color, by implementing an inline if
syntax.
In this tutorial we're going to purposely make some common Twig mistakes, debug them, and figure out how to fix them. We'll also look at a way to make parts of your Twig code easily reusable, using macros.
Twig: The Basics
FreeTwig is a templating language for PHP, which is a boring way of saying that it’s a tool used to output variables inside HTML. In this series we'll show you how to use Twig from the ground up, clearly pointing out its syntax, and then graduating to some really neat and advanced tricks. We'll start with a look at Twig syntaxes, functions and filters. Then we'll get into the world of debugging with the dump()
function. With the basics under control, we'll move to handling arrays and objects. template inheritance, tests, looping tricks, and macros (Twig functions).
To make this interesting, we're going to build something useful with Twig, like a penguin clothing store! We're starting out with a small website set up under your web server’s document root and a test page called test.php, which you can find in the series demo site download. In this lesson, you will create your first Twig template, render a variable, and learn the basic Twig syntax you'll need to know.
Additional resources
Chapter 14: Final Thoughts
CourseTwig is the theme template engine in Drupal as of version 8. Like any code, there are guidelines and standards that dictate both the style and the structure of the code. In this tutorial we will explain how to adhere to the Drupal code standards while implementing Twig templating.
By the end of this tutorial you will be able to adhere to Drupal's coding standards when writing Twig, and know where to find more information about the guidelines when necessary.
Twig Templating
CourseYou've got a slick responsive theme for your Drupal site that's been implemented in CSS using media queries. But the content and images on your site will regularly be updated and you want to use the Responsive Images module to create responsive image style field formatters that you can apply to image field display settings.
In this lesson, we'll review the concepts of breakpoints and media queries so that you can better understand what's going on when you encounter them in non-CSS file contexts like configuration forms for responsive image styles or breakpoint YAML files.
By the end of this tutorial, you should have an understanding of what breakpoints are, how they are expressed in media queries, and how they are relevant in the context of Drupal.
Some, but not all, themes come with administrator-configurable settings that you can change through the UI. These might allow you to upload your own logo, choose between a couple of different pre-defined layouts, or turn features of a theme on or off. In this tutorial we’ll look at where you can find these theme settings if they exist, and how to go about changing them.
Preprocess functions are specially-named PHP functions that allow themes and modules to modify the variables passed to a Twig template file. They are commonly used by themes to alter existing variables before they are passed to the relevant template files. For example; Changing the makeup of render array so that it renders an <ol>
list instead of a <ul>
list. Or appending data to the label of a node depending on custom logic.
In this tutorial we'll:
- Define a new preprocess function in our theme's .theme file
- Use the preprocess functions to modify the content of an existing variable before it's used in Twig
By the end of this tutorial you should be able to define new preprocess functions in a theme (or module) that manipulate the variables for a specific Twig template file.
Theme developers often need to add or remove classes and other attributes from an HTML tag. Template files handle this with a special Attributes object that contains the attributes and their values, as well as a handful of powerful methods to help manage these attributes.
In this tutorial we’ll cover:
- Adding/removing classes from elements in a Twig template
- The attributes object
- Examples of common tasks using various helper methods on the attributes object
Making Drupal fast by default implies having caching layers and CSS and JavaScript aggregation utilities enabled out-of-the-box. As a theme developer this can be annoying, because you must clear these various caches in order to preview any changes. In addition, inspecting variables with debugging tools often produces PHP errors. We'll make some recommendations for PHP settings on your local environment that can prevent these errors from happening so often.
By the end of this tutorial, you should be able to:
- Set up your local Drupal site for theme development
- Prepare your local development environment for working on and debugging themes
Core Themes: Bartik
FreeBartik is a core theme in Drupal. As a default theme for Drupal, it serves as an instructive example of a well-developed responsive theme. In this tutorial, we'll tour and explore Bartik, identify its primary features, and explain the use case for the Bartik theme and what you can learn from it.
Core Themes: Stark
FreeStark is one of the themes bundled with Drupal. It is intentionally bare bones and its purpose is to help Drupal theme and module developers get to the heart of Drupal's system templates. In this tutorial, we'll explore Stark and its primary features and discuss the various reasons for utilizing the Stark theme.