In the context of expanding project scale and the widespread adoption of TypeScript, traditional prop validation methods in Vue.js components reveal shortcomings such as insufficient type hints and runtime overhead. Traditional prop validation suffers from tight coupling between type definitions and runtime checks, lacks support for complex type hints, fails to provide type hints in templates, and incurs performance costs due to validation logic. Vue 3's `defineProps` macro, combined with TypeScript, enables compile-time type checking, delivers full IDE support, handles complex types, and incurs zero runtime overhead. For scenarios requiring dynamic validation, it can be paired with `withDefaults` and runtime checks. Leveraging TypeScript's advanced features, it supports conditional types and generic components, enabling powerful prop typing. When integrated with the Composition API, it maintains a complete type chain, including props-derived state and emit event types. Improvements to the type system enhance performance by reducing runtime check overhead and providing more precise type hints. A recommended migration strategy involves incrementally adding type annotations to existing props and transitioning to pure type definitions. A type-safe event system enables strict validation of emit event payloads, and type-safe prop utility functions can be created. Additionally, TypeScript types can automate documentation generation and handle edge cases like dynamic components and recursive types.
Read more
In Vue.js, the `emits` option is used to explicitly declare the events a component can trigger, supporting both array and object formats. The object format allows for the addition of validation functions. Using `emits` aids in component self-documentation, type checking, and runtime validation. In Vue 3, undeclared events are treated as native events. `emits` is often paired with `props` to facilitate parent-child component communication. In TypeScript, precise event payload types can be defined. It is recommended to use kebab-case for event names to avoid conflicts with native events. Validation functions can perform complex logic checks. In the Composition API, events are triggered via the `emit` parameter in `setup`. Vue 3 supports multiple `v-model` bindings, where `emits` plays a key role. During testing, event triggering can be verified. `emits` can also be used to encapsulate third-party library events or replace the event bus pattern. Dynamic event names must be declared in advance. Note the distinction between native events and custom events. Event parameters can be destructured or passed through slots.
Read more
In Vue 3, the definition of asynchronous components is achieved through `defineAsyncComponent`, replacing Vue 2's import syntax. This API provides basic usage and advanced configuration options, including loading state handling, error boundaries, and integration with Suspense. It supports dynamic imports and code splitting, can be directly used in the Composition API, and integrates with routing and state management. Special handling is required for SSR environments, and testing must account for asynchronous behavior. In TypeScript, it offers full type support and is suitable for modular loading and performance optimization scenarios in large-scale applications.
Read more
Vue 3 significantly upgraded component v-model by supporting multiple v-model bindings, addressing the limitation of single binding in Vue 2. Through the v-model argument syntax, it enables multi-data flow control, requiring components to handle props and emit events separately for each parameter. This proves particularly useful in complex form scenarios while also supporting custom modifier processing as a replacement for Vue 2's .sync modifier. The article elaborates on the implementation principles, application scenarios, and integration with Composition API and TypeScript, providing performance optimization suggestions and common issue solutions. It demonstrates how to collaborate with features like provide/inject, offering developers more powerful tools for handling complex component communication.
Read more
Vue 3's Composition API addresses the code fragmentation issue of the Options API in complex components by centralizing reactive data and logic management through the `setup` function. Core concepts include creating reactive data using `ref` and `reactive`, enabling logic reuse via composable functions, and providing lifecycle-equivalent hooks. Compared to the Options API, it offers better code organization and TypeScript support. The article details advanced usage such as props handling, state management integration, and asynchronous operations, along with solutions to common issues like reactive value loss, template refs, and dependency injection. Finally, it shares performance optimization techniques, third-party library integration methods, and best practices for enterprise-level application architecture, including layered design, global state management, and routing control.
Read more
Vue 3 has introduced several significant improvements in component registration: global component registration is now done via the `app.component` method, supporting multiple coexisting applications; local component registration is more flexible in the Composition API; async components are defined using the new `defineAsyncComponent` API; component naming recommends PascalCase; dynamic components require distinguishing between components and native elements; functional components must be explicitly defined, and the `functional` option is no longer supported; `v-model` supports multiple bindings and custom modifiers; custom elements are configured via `compilerOptions`; component inheritance removes `listeners` and the `native` modifier; component instance properties have changed; recursive components require explicit naming; scoped styles have been optimized; TypeScript support is enhanced; and component performance is improved, including reduced impact of global registration and lower overhead for functional components.
Read more
Vue.js application runtime size optimization employs multiple strategies: code splitting and lazy loading via dynamic imports for on-demand loading of routes and components, avoiding full imports of third-party libraries, leveraging Tree Shaking to remove unused code, component-level optimizations including avoiding complex template expressions and using computed properties, compile-time optimizations like whitespace compression, lightweight alternatives such as native APIs instead of libraries, static resource optimizations like inlining SVGs, build configurations enabling compression and debug code removal, runtime feature trimming to eliminate unnecessary functionality, SSR with separate client and server builds, long-term caching using filename hashing, and monitoring and analysis via visualization tools for continuous size tracking. Combining these methods effectively reduces Vue application runtime size and enhances performance.
Read more
Event caching is an optimization technique that stores triggered events and their processing results to avoid redundant calculations or requests. In Vue.js, computed properties, methods, and watchers are commonly used for implementation. Computed properties cache based on dependency relationships, while methods execute on every call but can be manually cached. Advanced caching strategies may involve using a Map or object for storage with added expiration times. Event modifiers like `once` ensure events execute only once. Vuex can implement caching via getters and actions. Cache invalidation strategies include time-based expiration, dependency changes, and manual clearing. Performance requires balancing memory usage, and third-party caching libraries can be integrated. Server-side rendering must account for memory leaks, and component lifecycle impacts caching strategies, such as cleanup on destruction and handling with `keep-alive`.
Read more
Vue.js static node hoisting is a compiler optimization strategy that identifies static nodes in templates that remain unchanged and hoists them outside the render function to avoid the performance overhead of repeated rendering. Static nodes include pure text nodes and element nodes without dynamic bindings. The advantages lie in reducing the overhead of virtual DOM creation, optimizing the patch process, and improving memory efficiency. Vue can identify and hoist entire static subtrees, which is particularly effective in SSR. The `v-once` directive can be used to force hoisting, and compiler configurations can adjust hoisting behavior. It is compatible with the Composition API but has limitations such as increased memory usage. Best practices include splitting large static content and using `v-once` judiciously. Compared to other frameworks, Vue 3's static hoisting is more aggressive and supports more scenarios. In the future, it will better integrate with new features like Suspense.
Read more
Vue.js offers diverse component communication methods. Traditional approaches include props and custom events, where parent components pass data via props and child components trigger events with emit. Provide/inject allows ancestor components to inject dependencies into any descendant. In Vue 2, event buses were commonly used for cross-component communication, while Vue 3 recommends third-party libraries like mitt. Large-scale applications can adopt Vuex for centralized state management. The Composition API introduces new communication patterns, enabling flexible state sharing through the setup function and ref/reactive. Teleport is used for special cross-component rendering scenarios, and custom directives are suitable for direct DOM manipulation. Reactive storage can serve as a lightweight alternative to Vuex. Using Symbol as a key for provide/inject avoids naming conflicts, while EffectScope better manages side effects in composable functions.
Read more
