How to Share JavaScript Code in LWC

 In Lightning Web Components (LWC), there are two primary patterns for code sharing:

1. Module Pattern:

• Usage: This pattern involves creating reusable JavaScript modules that can be imported into LWC components.
• Implementation: You create separate JavaScript files containing reusable code, then import these modules into your LWC components using the ES6 import statement.
• Benefits: Encourages modularity, reusability, and separation of concerns. It allows you to organize your codebase effectively and promotes maintainability.
• Example: As described in the previous response, creating a JavaScript module (sharedUtils.js) and importing it into components.
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3. Base Components Pattern:

   • Usage: This pattern involves creating base components that encapsulate common functionality and can be extended or customized by other components.
   • Implementation: You create base components that contain common logic or UI elements. Other components can then extend these base components to inherit their functionality.
   • Benefits: Promotes code reuse and consistency across the application. It simplifies development by providing a standardized way to implement common features.
   • Example: You might create a base component for a custom modal dialog that includes methods for showing and hiding the modal. Other components can extend this base component to create specific modal instances with customized content.

The first pattern is used in this instance. Only myComponent.js has the ability to import code from myFunction.js and utils.js.

lwc

└───myWgComponent

├──myWgComponent.html

├──myWgComponent.js

├──myWgComponent.js-meta.xml

├──myWgFunction.js

└──wgutils.js

 Utilize relative paths when importing the code.

// myComponent.js

import { getMonthlyAmount, calculateMonth} from ‘./myWgfunction;

import WgCalender from ‘./wgutils; 

Another illustration is a service component (library). The name of the folder and one JavaScript file must match. The name in this instance is wgUtils. 

lwc

├──wgUtils

├──wgUtils.js

└──wgUtils.js-meta.xml

└───wgComponent

├──wgComponent.html

├──wgComponent.js

└──wgComponent.js-meta.xml

 

For importing the code into other components, use c/componentName syntax.

// wgComponent.js

import { getOptions, calculatePayment } from ‘c/wgUtils’;

Both patterns have their strengths and are suitable for different scenarios. The choice between them depends on factors such as the complexity of the shared functionality, the level of customization required, and the architecture of your application. Using a combination of both patterns can often provide a flexible and scalable approach to code sharing in LWC.