What if you could build Vue 3's reactivity from scratch? See how ES6 Proxies make it possible in under 30 lines of code.
#1about 3 minutes
Understanding the core principles of reactivity
Reactivity is explained as an automated observer pattern where changes to data trigger updates wherever that data is used.
#2about 2 minutes
Using ES6 Proxies to intercept data access
ES6 Proxies wrap objects and allow interception of operations like getting or setting properties, which is the foundation for Vue 3's reactivity.
#3about 4 minutes
Architecting the reactivity system with maps and sets
The system uses a WeakMap to store a Map for each object, which in turn stores a Set of effects for each property.
#4about 5 minutes
Demonstrating the problem with manual state updates
The initial code shows how changing a product's price or quantity requires manually recalculating the total each time.
#5about 3 minutes
Building manual track and trigger functions
The `track` function adds an effect to a Set, and the `trigger` function iterates over the Set to execute all tracked effects.
#6about 11 minutes
Building a reactive function with ES6 Proxies
A `reactive` function is created using an ES6 Proxy to intercept property access, with `get` handlers calling `track` and `set` handlers calling `trigger`.
#7about 4 minutes
Automating dependency tracking with an effect function
The `effect` function wraps a piece of code, sets it as the `activeEffect`, and runs it once to automatically track all accessed reactive properties.
#8about 6 minutes
Connecting the reactive system to the DOM
The final step demonstrates the complete system by linking the reactive state to DOM elements, which update automatically when the state changes.
#9about 12 minutes
Answering audience questions about reactivity and career
The speaker answers questions about proxy performance, nested objects, career journey, and identifying reactive objects in a large codebase.
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Matching moments
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02:31 MIN
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04:19 MIN
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Navigating state management patterns and their trade-offs
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01:27 MIN
Understanding the core concept of reactivity
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03:46 MIN
Creating observable state with JavaScript proxies
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04:25 MIN
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