Shopify Themes and App Development

Historical Context

• Shopify's platform initially offered third-party themes.
• 2010: Launch of the Shopify Theme Store inviting third-party designers.
• API Platform and App Store launched 10 months prior, allowing online merchants to develop and sell applications.

Themes vs. Apps

• Themes: Different versions of online storefronts, customizable with Liquid, HTML, CSS, and JavaScript.
• Apps: Custom interfaces extending Shopify admin, utilizing Shopify's admin API to affect backend and frontend.

Theme App Extensions

• Before Extensions: Apps used the asset API, needing merchants to copy HTML code into themes.
• Theme App Extensions Introduced: Solves issue of embedding app code within themes, storing code within the app itself.
  • App Blocks: Code integrated as blocks in the theme editor.
  • App Embed Blocks: Allows for overlay or floating elements, injects into the theme’s head or body.

Creating a Shopify App with Theme App Extension

Requirements

• Development store and Shopify partner's account.
• Shopify CLI, Node 16+, npm/yarn/pnpm.

Steps

1. Initialize App: Use npm init @shopify/app@latest.

2. App Project Setup

   • Choose Node for JavaScript development.
   • Create App and Theme App Extension.

3. Code Structure

   • Extensions folder mimics theme structure with assets, blocks, locales, snippets.
   • Use of app block in schema for integration.

Publishing App

• Use Shopify Partners account to create and publish app versions.
• Deploy extensions and manage through Shopify Partner's account.

App Block Customization

• App blocks customizable via Shopify customizer.
• Meta fields can be dynamically linked to display in theme.

App Embed Blocks

• Used for floating elements or additional JavaScript/CSS.
• Managed via theme settings under app embeds.

Considerations for Theme Developers

• Theme developers have limited control over app code.
• App developers must ensure apps are customizable and hosted properly.
• App extensions offer a cleaner, more manageable integration with themes.

Limitations

• Hosted on developer servers; app interface breaks without server.
• Customization options limited to what app developers provide.

Conclusion

• Understanding app extensions is crucial for both app and theme developers.
• They provide a structured way to manage and integrate apps within Shopify themes.