https://github.com/wkornewald/ts-immutable-struct
TypeScript package for using immutable.js with type-safe cursors and a central event system (as a Redux alternative)
https://github.com/wkornewald/ts-immutable-struct
cursor cursors events immutable immutablejs typescript
Last synced: about 2 months ago
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TypeScript package for using immutable.js with type-safe cursors and a central event system (as a Redux alternative)
- Host: GitHub
- URL: https://github.com/wkornewald/ts-immutable-struct
- Owner: wkornewald
- License: mit
- Created: 2017-06-24T20:24:49.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2020-07-17T11:24:34.000Z (about 5 years ago)
- Last Synced: 2025-07-08T09:19:09.853Z (3 months ago)
- Topics: cursor, cursors, events, immutable, immutablejs, typescript
- Language: TypeScript
- Homepage:
- Size: 85 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# ts-immutable-struct
[](https://badge.fury.io/js/ts-immutable-struct)
[](https://npmjs.org/package/ts-immutable-struct)
[](https://travis-ci.org/wkornewald/ts-immutable-struct)
`ts-immutable-struct` is a TypeScript package for using `immutable.js` with type-safe cursors
and simple event tracking to allow distinguishing between user-initiated state changes and
internal state changes (e.g. to sync state).
The emphasis here is on type-safety.
This package is inspired by [immstruct](https://github.com/omniscientjs/immstruct), but uses references for everything.
React users will want to combine this with [ts-react-struct](https://github.com/wkornewald/ts-react-struct), so
`shouldComponentUpdate()` works with `ts-immutable-struct` cursors.
## Getting started
Install the package:
```sh
npm install --save ts-immutable-struct
```
Initialize the global state struct:
```typescript
import {Struct} from 'ts-immutable-struct'
let data = Struct({
a: 5,
b: 'hey',
c: null as string | null,
d: [1, 2, 3],
e: [true, true, false],
f: ['a', 'b', 'c'],
g: [{a: 40, b: ['d']}, {a: 50, b: ['e']}],
l: [[60]],
o: {f: 65},
da: new Date(),
})
data.observe((event, oldVal, newVal) => {
// Handle state changes (oldVal and newVal are both cursors, so you'll need to deref())
})
```
Note that `Struct()` will internally convert the given argument to an immutable.js object using `immutable.fromJS()`.
Here's how to traverse and mutate the `Struct` state:
```typescript
// retrieve a value
let a = data.get('a').deref()
// update a value
data.get('g').get(0).get('a').val(99)
// alternative
data.get('g').get(0).get('a').update(x => x + 1)
// update the underlying immutable.js value
data.get('g').get(0).update(x => x.set('a', 99))
```
Everything here is type-checked. A wrong property name or type results in a compile-time error.