Shopify Liquid Guide

As we step into the world of Shopify Liquid, let’s begin by understanding its history, its primary components, and its functional aspect in a real-world scenario.

The Evolution of Liquid

Liquid was born out of Shopify’s ambition to provide a flexible and safe environment for customizing online stores. Developed in 2006, Liquid is an open-source templating language used not only by Shopify but also by other platforms like Jekyll for loading dynamic content on web pages. Over the years, Liquid has grown, adapted, and proved its worth as a powerful tool for e-commerce customization, providing countless store owners with the ability to mold their online storefronts according to their unique business needs.

The Building Blocks of Liquid: Objects, Tags, and Filters

Liquid’s magic lies in its simplicity and versatility, largely due to its fundamental components: Objects, Tags, and Filters. 

Objects in Liquid are used to show content on the storefront. They act as placeholders that get replaced with actual content when the page is rendered. Imagine objects as empty containers that are filled with the relevant data, like product details or customer information, at the time of display.

Tags are the control flow statements and are used for logic operations. If you think of creating your Shopify store as a journey, tags are the signposts that guide how you move from one point to another, dictating loops, conditions, and variable assignments.

Filters are the tools for manipulating the output of numbers, strings, variables, and objects. If objects are your raw materials and tags are your blueprints, filters are the tools that help you shape and modify the materials to fit perfectly into your blueprints.

The Practical Functioning of Shopify Liquid

Understanding how these components work in unison can help you appreciate Shopify Liquid’s power and efficiency. When a customer visits your Shopify store, Liquid code runs behind the scenes. It dynamically fetches the required data, applies necessary logic, manipulates the data as needed, and then seamlessly stitches everything together to present a customized, data-filled web page to the visitor. This entire operation is carried out swiftly, providing a smooth user experience.

For instance, let’s say you want to display a list of all product names in a collection. Here, ‘product’ is an object, ‘for’ is a tag that initiates a loop through each product in the collection, and ‘title’ is a property of the product object. The corresponding Liquid code would be:

{% for product in collection.products %}

    {{ product.title }}

{% endfor %}

In this snippet, the Liquid engine fetches all the products from the specified collection, loops through each one, and then displays each product’s title. This dynamic operation is what makes Liquid a powerful templating language for Shopify and beyond.

Liquid objects are the building blocks containing data that you can output onto your pages. These objects contain information about your Shopify store, such as product details, cart information, or user data.

For instance, if you wanted to display a product’s price, you’d use the `product` object like this:

{{ product.price | money }}

Liquid tags are the logic in your theme. They create loops, conditions, and control flow in your Liquid code.

For example, you can use tags to loop through all the products in a collection like this:

{% for product in collection.products %}
    {{ product.title }}
{% endfor %}

Filters in Liquid are used to modify the output of numbers, strings, variables, and objects. They’re used within an output and are separated by a pipe `|`.

For example, to format a product’s price, you’d use the `money` filter:

{{ product.price | money }}

With Liquid, you can achieve advanced functionality such as creating pagination, custom forms, and interactive elements like dropdowns and sliders. It also allows for seamless integration with Shopify’s powerful APIs for an enriched e-commerce experience.

Even though Liquid simplifies coding for non-developers, it’s still essential to follow certain coding standards and guidelines.

Consistent Formatting: Ensure to use consistent indentation and whitespace for readability.

Comments: Use comments to explain complex parts of your code. In Liquid, you can comment with

{% comment %} ... {% endcomment %}

 

• Naming Conventions: Choose clear, descriptive names for your variables and files.
• Organized Code Structure: Keep related code and files together.
• Code Reusability: Reuse code snippets where possible to keep your code clean.
• Error Handling: Anticipate and plan for potential errors. 
• Limit Liquid Logic: Try to keep heavy logic and computations on the server-side if possible.

When working with Shopify themes, Liquid programming language comes to your aid by helping you manage a wide range of customizable features. Let’s explore a few practical examples of how Shopify uses Liquid to enhance its themes:

1. Display Product Details:

One of the most common Shopify uses of Liquid is displaying product information. Each product object in your Shopify store is loaded with details like the product’s title, price, description, images, and more. You can use Liquid code in your theme’s template files to display these details.

<!-- Product Title -->

{{ product.title }}




<!-- Product Price -->

{{ product.price | money }}




<!-- Product Description -->

{{ product.description }}

2. Customize Layouts Based on Conditions:

Liquid’s syntax supports conditional statements, allowing you to change your Shopify theme’s layout based on certain conditions. For instance, you might want to display different headers for different product categories.

{% if product.type == 'Shirt' %}

  <!-- Liquid code for the Shirt category header goes here -->

{% elsif product.type == 'Pants' %}

  <!-- Liquid code for the Pants category header goes here -->

{% else %}

  <!-- Liquid code for the default header goes here -->

{% endif %}

3. Iterating Over Collections:

Liquid enables you to iterate over collections, which is particularly useful when you want to display all products within a particular collection on your Shopify theme.

{% for product in collection.products %}

  <h2>{{ product.title }}</h2>

  <p>{{ product.description }}</p>

{% endfor %}

 

4. Personalizing User Experience:

Shopify Liquid programming can be used to personalize user experiences based on customer information. For instance, you could welcome back a returning customer by their first name.

{% if customer %}

  <p>Welcome back, {{ customer.first_name }}!</p>

{% endif %}

 

5. Format and Transform Data:

Liquid filters can help format and manipulate the data that’s displayed on your Shopify store. For example, you might want to change the case of product titles or format the prices and dates.

<!-- Convert a product title to uppercase -->

{{ product.title | upcase }}




<!-- Format a date -->

{{ article.published_at | date: "%b %d, %Y" }}

 

These are just a handful of examples. With a grasp of Liquid syntax and an understanding of its capabilities, you can create powerful, dynamic, and highly personalized experiences for visitors to your Shopify store. The combination of Shopify themes and Liquid’s flexible programming makes it possible to create an e-commerce store that truly stands out.

Navigating through the world of Liquid can be made much simpler with a handy cheat sheet. Here’s a quick reference guide to get you up and running with Shopify’s powerful templating language.

1. Created by Shopify:

Liquid is an open-source templating language developed by Shopify. It was written in Ruby and is used to load dynamic content on web pages.

2. Basic Syntax:

Liquid syntax includes objects, tags, and filters. Objects and variable outputs are surrounded by double curly braces `{{ }}`, while tags are enclosed in curly brace-percent symbols {% %}.

3. Objects:

Objects contain data that can be output onto your Shopify store’s pages.

<!-- Display the product title -->

{{ product.title }}




<!-- Display the product price -->

{{ product.price }}

4. Tags:

Tags create logic and control flow in your Liquid code. This includes loops, conditionals, and theme tags.

<!-- For loop to display all products in a collection -->

{% for product in collection.products %}

  {{ product.title }}

{% endfor %}



{% if product.available %}

  Product is in stock.

{% else %}

  Out of stock.

{% endif %}

5. Filters:

Filters change the output of an object or variable. They are used within an output and are denoted by a pipe |.

<!-- Format a product price -->

{{ product.price | money }}

<!-- Convert a string to uppercase -->

{{ 'hello world' | upcase }} <!-- Output: 'HELLO WORLD' -->

6. Assign:

The `assign` tag creates a new variable.

<!-- Assign a variable -->

{% assign favorite = 'chocolate' %}

My favorite ice cream is {{ favorite }}. <!-- Output: 'My favorite ice cream is chocolate.' -->

7. Liquid Files:

Liquid files are the backbone of your Shopify theme. They build up the structure and layout of your store. There are three main types of liquid files:

• Layout files: These files form the outermost shell of your theme. They hold code that’s shared across all pages of your website, like headers and footers.
• Template files: These files dictate the way content is displayed on different types of pages (like the product page or the collection page).
• Snippets: These are chunks of reusable code that can be included in other Liquid files.

8. Static Content:

Static content that does not change based on conditions can also be added to your Shopify pages using Liquid. This includes text, images, and more.

<!-- Display a static message -->

Welcome to our store!

<!-- Display a static image -->

<img src="{{ 'image.png' | asset_url }}" alt="Image description">

This cheat sheet serves as a quick reference guide to the basics of Shopify Liquid, helping you get started on your journey to building dynamic and personalized Shopify themes.