29 lines
872 B
Markdown
29 lines
872 B
Markdown
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# Observable
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Create a function `makeObservable(target)` that "makes the object observable" by returning a proxy.
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Here's how it should work:
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```js run
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function makeObservable(target) {
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/* your code */
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}
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let user = {};
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user = makeObservable(user);
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user.observe((key, value) => {
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alert(`SET ${key}=${value}`);
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});
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user.name = "John"; // alerts: SET name=John
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```
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In other words, an object returned by `makeObservable` has the method `observe(handler)`.
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Whenever a property changes, `handler(key, value)` is called with the name and value o the property.
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P.S. In this task, please handle only writing to a property. Other operations can be implemented in a similar way.
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P.P.S. You might want to introduce a global variable or a global structure to store handlers. That's fine here. In real life, such function lives in a module, that has its own global scope.
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