Warning: Documentation is out of date! Please refer to TypeScript intellisense. (New Accessor is $
, not Symbol(value)
)
- Small: 0.91 KiB / gzip: 0.47 KiB
- Splendid: observe any values and function calls
- Smart: all nested values notified on parent change
- Simple: 1 function, 4 symbols
- Sweet: beloved accessor syntax
- Speedy: location based proxy allocation
A tiny documentation for a tiny library...
npm i obsx
# or
yarn add obsx
import { observe, value, onChange, onApply, notifyChange } from "obsx";
// or
const { observe, value, onChange, onApply, notifyChange } = require("obsx");
interface TreeNode {
value: number;
parent?: TreeNode;
nodes: TreeNode[];
}
const data = observe<TreeNode>({
value: 0,
nodes: [],
});
Detect changes in a value, which can be not yet defined. Updating a parent object will notify all observers recursively for nested values.
const stop = data.value[onChange]((current, previous) => {
console.log(`data.value changed from ${previous} to ${current}`);
});
data.value[value]++; // data.value changed from 0 to 1
data[value] = { value: 2, nodes: [] }; // data.value changed from 1 to 2
stop();
data.value[value]++; // silence...
Detect when the function is called. The function can be undefined when registering the observer.
const stop = data.nodes.push[onApply]((...nodes) => {
console.log(`data.nodes has new nodes!`, nodes);
});
data.nodes.push({ value: 1, nodes: [] });
// data.nodes has new nodes! [{value: 1, nodes: []}]
stop();
data.nodes.push({ value: 1, nodes: [] }); // silence...
The default behavior won't call the change observer if there are no changes.
data.value[onChange](() => {
console.log("I did not change...");
});
data.value[notifyChange](true);
data.value[notifyChange](true);
data.value[notifyChange](true);
// I did not change (3 times)
ObsX uses Proxies to allow for the sweet syntax you see above. It caches proxies on the location level, in contrast to the object level caching used in Vue. Therefore, it won't create a new Proxy on every assignment, but rather on every path access.
With JIT-compiler optimizations, it should not be much slower than implementing all its functionalities without the fancy syntax provided by proxies.
This project is licensed under the MIT License.