Migrate Get/set Owner: Ember Application To Ember Owner

Nov 25, 2025 by Alex Johnson 56 views

Migrating `get/set Owner` from `@ember/application` to `@ember/owner`: A Comprehensive Guide

Migrating from @ember/application to @ember/owner for get/set Owner can seem daunting, but with the right guidance, it can be a smooth transition. This comprehensive guide provides a detailed walkthrough for both library authors and application developers, ensuring everyone can seamlessly adopt the new @ember/owner API. We will explore the necessary steps, code examples, and best practices to make this migration as straightforward as possible. Understanding the nuances of this migration is crucial for maintaining the health and compatibility of your Ember applications and libraries. This guide aims to provide clarity and actionable steps so that you can confidently make the switch. By following the methods outlined here, you can ensure your codebase remains up-to-date with the latest Ember conventions and improvements. Transitioning to @ember/owner not only aligns your code with modern Ember practices but also sets the stage for future enhancements and optimizations within the Ember ecosystem. Let’s dive in and explore the intricacies of migrating get/set Owner effectively.

For Library Authors: Supporting Both `@ember/application` and `@ember/owner`

As library authors, it's essential to support a wide range of Ember versions to ensure your library can be used by as many applications as possible. This section provides a TypeScript-based approach for supporting both @ember/application and @ember/owner. This dual support allows your library to function correctly in older Ember versions while also taking advantage of the newer @ember/owner API in more recent versions. The key is to use conditional imports and type definitions to abstract away the differences between the two APIs. This strategy ensures that your library remains compatible and future-proof. By implementing this approach, you can avoid breaking changes for your users and provide a seamless experience regardless of their Ember version. The code snippets below demonstrate how to achieve this using @embroider/macros, which is a powerful tool for conditional compilation in Ember addons. Let's explore the code and understand how it facilitates the smooth transition between different Ember versions. By providing support for both APIs, you are not only enhancing the usability of your library but also contributing to the overall stability and adaptability of the Ember ecosystem. We'll break down the code step by step, explaining each part and its role in achieving compatibility.

TypeScript Code Snippet for Dual Support

import { appEmberSatisfies, importSync, macroCondition } from '@embroider/macros';
import type Owner from '@ember/owner';

interface CompatOwner {
 getOwner: (context: unknown) => Owner | undefined;
 setOwner: (context: unknown, owner: Owner) => void;
}

export const compatOwner = {} as CompatOwner;

if (macroCondition(appEmberSatisfies('>=4.12.0'))) {
 // In no version of ember where `@ember/owner` tried to be imported did it exist
 // Using 'any' here because importSync can't lookup types correctly
 compatOwner.getOwner = (importSync('@ember/owner') as any).getOwner;
 compatOwner.setOwner = (importSync('@ember/owner') as any).setOwner;
} else {
 // Using 'any' here because importSync can't lookup types correctly
 compatOwner.getOwner = (importSync('@ember/application') as any).getOwner;
 compatOwner.setOwner = (importSync('@ember/application') as any).setOwner;
}

// usage
compatOwner.getOwner(this)

Explanation of the Code

Import Statements: The code begins by importing necessary modules from @embroider/macros and defining the Owner type from @ember/owner. @embroider/macros provides powerful tools for conditional compilation, allowing us to tailor the code based on the Ember version. The Owner type definition ensures that we have the correct type information for the getOwner and setOwner methods. This setup is crucial for ensuring type safety and compatibility across different Ember versions. Using @embroider/macros enables us to write code that adapts to the environment in which it is running, making it a versatile tool for library authors.
CompatOwner Interface: An interface CompatOwner is defined to provide a consistent type for the getOwner and setOwner methods. This interface acts as an abstraction layer, allowing us to work with both the old and new APIs without directly referencing them. The CompatOwner interface ensures that our code remains type-safe and easy to maintain, regardless of the underlying implementation. This abstraction is key to supporting multiple Ember versions without introducing complex branching logic throughout the codebase.
Conditional Logic with macroCondition: The core of the compatibility logic lies within the if statement, which uses macroCondition and appEmberSatisfies from @embroider/macros. This allows us to check the Ember version at build time and include the appropriate code. If the Ember version is 4.12.0 or higher, the code imports getOwner and setOwner from @ember/owner; otherwise, it imports them from @ember/application. This conditional import ensures that the correct API is used based on the Ember version, making the library compatible with a wide range of applications.
Dynamic Imports with importSync: The importSync function is used to dynamically import the necessary modules. This is crucial because it allows us to import modules that might not be available in all Ember versions. The importSync function ensures that the correct modules are loaded based on the conditional check, making the library adaptable to different environments. Dynamic imports are essential for achieving compatibility without sacrificing performance or code clarity.
Usage Example: The final line compatOwner.getOwner(this) demonstrates how to use the compatOwner object. This provides a simple and consistent API for accessing the owner, regardless of the Ember version. By using the compatOwner object, library authors can abstract away the complexities of version compatibility and focus on implementing their core functionality. This consistent API simplifies the development process and makes the library easier to use for application developers.

For Application Developers: Using Libraries that Depend on `@ember/owner`

Application developers might find themselves using libraries that have already migrated to @ember/owner, even if their application is behind Ember 4.11 (when @ember/owner landed in stable). In such cases, a polyfill is necessary to bridge the gap. This section outlines how to use the ember-polyfill-get-and-set-owner-from-ember-owner polyfill to enable compatibility. This polyfill ensures that your application can seamlessly use libraries that rely on the newer @ember/owner API, even if you are not yet ready to upgrade to Ember 4.11 or later. By incorporating this polyfill, you can avoid compatibility issues and continue to benefit from the latest library features and updates. The following steps will guide you through the process of installing and configuring the polyfill, making it easy to integrate into your Ember application. Let's explore the steps to ensure your application remains robust and compatible with the broader Ember ecosystem. By using this polyfill, you can keep your application up-to-date and take advantage of the improvements and features offered by modern Ember libraries.

Using `ember-polyfill-get-and-set-owner-from-ember-owner`

The ember-polyfill-get-and-set-owner-from-ember-owner polyfill is designed to provide the necessary compatibility layer for applications running older Ember versions. It essentially backports the getOwner and setOwner APIs from @ember/owner to @ember/application, allowing your application to interact seamlessly with libraries that use the newer API. This polyfill acts as a bridge, ensuring that your application can continue to function correctly while you plan your upgrade to a more recent Ember version. By using this polyfill, you can minimize the disruption caused by library dependencies and maintain a smooth development workflow. The polyfill is easy to install and configure, making it a valuable tool for application developers who need to support older Ember versions. Let's look at the steps to integrate this polyfill into your application and ensure compatibility with libraries that depend on @ember/owner.

Installation and Requirements

To use this polyfill, you need to meet certain requirements and follow specific installation steps. This section will guide you through the necessary prerequisites and the installation process, ensuring that you can successfully integrate the polyfill into your Ember application. Meeting these requirements is crucial for the polyfill to function correctly and provide the necessary compatibility. By following the installation steps outlined below, you can avoid common issues and ensure a smooth integration process. Let's dive into the requirements and steps needed to set up the ember-polyfill-get-and-set-owner-from-ember-owner polyfill in your application.

Requirements:

@embroider/macros 1.19.4 or higher (which does not require Embroider)

Installation Steps:

Install the Polyfill: Use npm or yarn to install the ember-polyfill-get-and-set-owner-from-ember-owner package.

npm install ember-polyfill-get-and-set-owner-from-ember-owner
# or
yarn add ember-polyfill-get-and-set-owner-from-ember-owner

Install @embroider/macros: Ensure you have @embroider/macros installed at version 1.19.4 or higher.
```
npm install @embroider/macros
# or
yarn add @embroider/macros
```

Explanation of Requirements

@embroider/macros: The polyfill relies on @embroider/macros for conditional compilation. This allows the polyfill to dynamically include the necessary code based on the Ember version. @embroider/macros is a powerful tool that enables conditional logic in Ember addons, making it essential for this polyfill's functionality. Using @embroider/macros ensures that the polyfill can adapt to different Ember versions and provide the correct implementation of getOwner and setOwner. The version 1.19.4 or higher is required because it includes the necessary features and fixes for the polyfill to work correctly. It's important to note that @embroider/macros does not require Embroider itself, making it a lightweight dependency for this use case.

Conclusion

Migrating get/set Owner from @ember/application to @ember/owner is a crucial step for staying current with Ember's evolving landscape. For library authors, providing dual support ensures compatibility across different Ember versions, enhancing the usability of your libraries. For application developers, the ember-polyfill-get-and-set-owner-from-ember-owner polyfill offers a seamless way to use libraries that have adopted @ember/owner, even in older Ember applications. By following the guidelines and code examples provided in this guide, you can confidently navigate this migration and keep your Ember projects up-to-date. Embracing these changes not only aligns your code with modern Ember practices but also sets the stage for future improvements and optimizations within the Ember ecosystem. Remember, staying informed and proactive about these migrations ensures the long-term health and maintainability of your Ember applications and libraries. We hope this guide has provided clarity and actionable steps to make this transition as smooth as possible. Keep exploring the Ember ecosystem and its evolving best practices to build robust and scalable applications.

For more information on Ember.js and its best practices, visit the Ember.js official website.