Slots & Content Projection Interview Questions

Slots are placeholders in components that allow parent components to pass content. Defined using <slot> element. Enable component composition and content projection. Basic slots receive any content passed between component tags.

Default slots provide fallback content. Example: <slot>Default content</slot>. Content appears when parent doesn't provide slot content. Useful for optional content.

Named slots target specific slot locations using name attribute. Example: <slot name='header'>. Content provided using slot='header' attribute. Allows multiple distinct content areas.

Content is passed to named slots using slot attribute. Example: <div slot='header'>Header content</div>. Must match slot name in component. Can pass any valid HTML or components.

Slot props pass data from child to parent through slots. Use let:propertyName directive. Example: <slot name='item' let:item>. Enables parent to access child component data.

Use $$slots object to check slot content. Example: {#if $$slots.header}. Available in component script and template. Useful for conditional rendering.

Fallback content appears when slot is empty. Defined between slot tags. Example: <slot>Fallback</slot>. Provides default UI when parent doesn't provide content.

Slots enable flexible component composition. Support content injection at multiple points. Allow component reuse with different content. Enable layout component patterns.

Slot content maintains parent component scope. Can access parent variables and functions. Cannot directly access child component state. Uses parent component context.

Slot content can be styled in both parent and child. Child styles using :slotted() selector. Parent styles apply normally. Support style encapsulation.

Conditional slots use if blocks around slots. Handle slot presence checks. Support dynamic slot selection. Example: {#if condition}<slot></slot>{/if}

Dynamic slot names use computed values. Support runtime slot selection. Handle dynamic content projection. Example: <slot name={dynamicName}>

Slot validation checks content type and structure. Handle invalid content. Support content restrictions. Implement validation logic.

Slot events bubble through component hierarchy. Handle event forwarding. Support event modification. Manage event propagation.

Slot middleware processes slot content. Handle content transformation. Support content filtering. Implement middleware chain.

Slot lifecycles manage content updates. Handle content mounting/unmounting. Support cleanup operations. Manage slot state.

Slot composition combines multiple slots. Handle nested slots. Support slot inheritance. Implement composition patterns.

Slot optimization improves rendering efficiency. Handle content caching. Support lazy loading. Manage update frequency.

Error boundaries catch slot content errors. Handle error recovery. Support fallback content. Manage error state.

Slot monitoring tracks content changes. Handle performance metrics. Support debugging tools. Manage monitoring state.

Advanced patterns include render props, compound slots. Handle complex compositions. Support pattern libraries. Implement reusable patterns.

Slot testing verifies content projection. Handle integration testing. Support unit tests. Implement test utilities.

Slot documentation describes usage patterns. Generate documentation automatically. Support example usage. Manage documentation updates.

Slot security prevents content injection. Handle content sanitization. Support content restrictions. Implement security policies.

Slot versioning handles API changes. Implement version migration. Support backwards compatibility. Manage version state.

Slot debugging tracks content flow. Handle debugging tools. Support breakpoints. Manage debug output.

Optimization strategies improve slot performance. Handle content caching. Support virtual slots. Implement update strategies.

State management handles slot-specific state. Implement state containers. Support state sharing. Manage state updates.

Slot accessibility ensures content is accessible. Handle ARIA attributes. Support screen readers. Implement a11y patterns.

Slots are placeholders in components that allow parent components to pass content. Defined using <slot> element. Enable component composition and content projection. Basic slots receive any content passed between component tags.

Default slots provide fallback content. Example: <slot>Default content</slot>. Content appears when parent doesn't provide slot content. Useful for optional content.

Named slots target specific slot locations using name attribute. Example: <slot name='header'>. Content provided using slot='header' attribute. Allows multiple distinct content areas.

Content is passed to named slots using slot attribute. Example: <div slot='header'>Header content</div>. Must match slot name in component. Can pass any valid HTML or components.

Slot props pass data from child to parent through slots. Use let:propertyName directive. Example: <slot name='item' let:item>. Enables parent to access child component data.

Use $$slots object to check slot content. Example: {#if $$slots.header}. Available in component script and template. Useful for conditional rendering.

Fallback content appears when slot is empty. Defined between slot tags. Example: <slot>Fallback</slot>. Provides default UI when parent doesn't provide content.

Slots enable flexible component composition. Support content injection at multiple points. Allow component reuse with different content. Enable layout component patterns.

Slot content maintains parent component scope. Can access parent variables and functions. Cannot directly access child component state. Uses parent component context.

Slot content can be styled in both parent and child. Child styles using :slotted() selector. Parent styles apply normally. Support style encapsulation.

Conditional slots use if blocks around slots. Handle slot presence checks. Support dynamic slot selection. Example: {#if condition}<slot></slot>{/if}

Dynamic slot names use computed values. Support runtime slot selection. Handle dynamic content projection. Example: <slot name={dynamicName}>

Slot validation checks content type and structure. Handle invalid content. Support content restrictions. Implement validation logic.

Slot events bubble through component hierarchy. Handle event forwarding. Support event modification. Manage event propagation.

Slot middleware processes slot content. Handle content transformation. Support content filtering. Implement middleware chain.

Slot lifecycles manage content updates. Handle content mounting/unmounting. Support cleanup operations. Manage slot state.

Slot composition combines multiple slots. Handle nested slots. Support slot inheritance. Implement composition patterns.

Slot optimization improves rendering efficiency. Handle content caching. Support lazy loading. Manage update frequency.

Error boundaries catch slot content errors. Handle error recovery. Support fallback content. Manage error state.

Slot monitoring tracks content changes. Handle performance metrics. Support debugging tools. Manage monitoring state.

Advanced patterns include render props, compound slots. Handle complex compositions. Support pattern libraries. Implement reusable patterns.

Slot testing verifies content projection. Handle integration testing. Support unit tests. Implement test utilities.

Slot documentation describes usage patterns. Generate documentation automatically. Support example usage. Manage documentation updates.

Slot security prevents content injection. Handle content sanitization. Support content restrictions. Implement security policies.

Slot versioning handles API changes. Implement version migration. Support backwards compatibility. Manage version state.

Slot debugging tracks content flow. Handle debugging tools. Support breakpoints. Manage debug output.

Optimization strategies improve slot performance. Handle content caching. Support virtual slots. Implement update strategies.

State management handles slot-specific state. Implement state containers. Support state sharing. Manage state updates.

Slot accessibility ensures content is accessible. Handle ARIA attributes. Support screen readers. Implement a11y patterns.