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Lately, I’ve been seeing this pesky console error in my WordPress admin: Store "core/interface" is already registered. If you’re building modern WordPress themes or plugins, you might have encountered it too. Let’s dive into what this means and how to fix it.

What’s a WordPress Data Store Anyway?

Think of WordPress data stores like specialized containers in your app’s memory. They’re part of WordPress’s @wordpress/data system – a Redux-like state management solution. Each store handles specific types of data:

  • core/interface: UI state management
  • core/editor: Gutenberg editor data
  • core/notices: WordPress admin notices
  • And so on…

Why Am I Seeing This Error?

The “Store Already Registered” error typically shows up when:

  1. Multiple parts of your code try to register the same store
  2. A plugin conflict causes duplicate registration
  3. WordPress core and your custom code both try to initialize the same store

It’s like two people trying to claim the same parking spot – it just doesn’t work.

Common Causes

1. Multiple @wordpress/data Versions

javascriptCopy// This might be loading in multiple places
import { createReduxStore, register } from '@wordpress/data';

2. Duplicate Store Registration

javascriptCopy// Bad: Registering the same store multiple times
registerStore('my-store', {/*...*/});
registerStore('my-store', {/*...*/}); // 💥 Boom! Error!

// Good: Check before registering
if (!wp.data.select('my-store')) {
    registerStore('my-store', {/*...*/});
}

3. Plugin Conflicts

Sometimes multiple plugins try to register the same store namespace:

javascriptCopy// Plugin A
registerStore('awesome-plugin/data', {/*...*/});

// Plugin B (accidentally uses same namespace)
registerStore('awesome-plugin/data', {/*...*/}); // Conflict!

How to Fix It

1. Use Store Registration Guards

javascriptCopyfunction registerMyStore() {
    if (wp.data && !wp.data.select('my-store')) {
        const storeConfig = {
            reducer: (state = {}, action) => {
                // Your reducer logic
                return state;
            },
            selectors: {
                // Your selectors
            },
            actions: {
                // Your actions
            },
        };
        
        wp.data.createReduxStore('my-store', storeConfig);
        wp.data.register(storeConfig);
    }
}

2. Use Unique Namespaces

javascriptCopy// Instead of generic names
registerStore('interface', {/*...*/});

// Use specific, namespaced identifiers
registerStore('my-theme/interface', {/*...*/});

3. Handle Dependencies Properly

javascriptCopy// In your webpack/rollup config
externals: {
    '@wordpress/data': 'wp.data',
    '@wordpress/element': 'wp.element',
    // other WordPress dependencies
}

Best Practices

  1. Always namespace your stores: Use prefixes like my-theme/ or my-plugin/
  2. Check before registering: Use registration guards
  3. Monitor dependencies: Make sure you’re not bundling multiple versions
  4. Use wp.data hooks: They handle registration more gracefully
javascriptCopy// Using wp.data hooks
import { useSelect } from '@wordpress/data';

function MyComponent() {
    const data = useSelect(select => {
        return select('my-store').getData();
    }, []);
    
    return <div>{data}</div>;
}

Debug Tools

Here’s a handy snippet to debug store registration:

javascriptCopywp.data.subscribe(() => {
    console.log('Current stores:', wp.data.select('core/data').getStores());
});

Wrapping Up

Store registration errors in WordPress might seem scary, but they’re usually just a sign that something’s trying to initialize twice. With proper namespacing, registration guards, and dependency management, you can keep your WordPress data layer clean and error-free.

Remember:

  • Namespace your stores
  • Check before registering
  • Manage dependencies carefully
  • Use WordPress’s built-in data hooks

Happy coding! 🚀


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