# `@virtualstate/navigation`
Native JavaScript [navigation](https://html.spec.whatwg.org/multipage/nav-history-apis.html#navigation-api) implementation
[//]: # (badges)
### Support
     
Test Coverage
    
npm / yarn / GitHub
- [Package Registry Link - GitHub](https://github.com/virtualstate/navigation/packages)
- [Package Registry Link - npm](https://www.npmjs.com/package/@virtualstate/navigation)
```
npm i --save @virtualstate/navigation
```
_Or_
```
yarn add @virtualstate/navigation
```
Then
```typescript
import { Navigation } from "@virtualstate/navigation";
```
Skypack
- [Package Registry Link - Skypack](https://www.skypack.dev/view/@virtualstate/navigation)
```typescript
const { Navigation } = await import("https://cdn.skypack.dev/@virtualstate/navigation");
```
_Or_
```typescript
import { Navigation } from "https://cdn.skypack.dev/@virtualstate/navigation";
```
importmap
[`importmap` documentation](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script/type/importmap)
```html
```
Examples
## Navigation
```typescript
import { Navigation } from "@virtualstate/navigation";
const navigation = new Navigation();
// Set initial url
navigation.navigate("/");
navigation.navigate("/skipped");
// Use .finished to wait for the transition to complete
await navigation.navigate("/awaited").finished;
```
## Waiting for events
```typescript
import { Navigation } from "@virtualstate/navigation";
const navigation = new Navigation();
navigation.addEventListener("navigate", async ({ destination, preventDefault }) => {
if (new URL(destination.url).pathname === "/disallow") {
preventDefault();
}
});
await navigation.navigate("/allowed").finished; // Resolves
await navigation.navigate("/disallow").finished; // Rejects
```
## Transitions
```typescript
import { Navigation } from "@virtualstate/navigation";
import { loadPhotoIntoCache } from "./cache";
const navigation = new Navigation();
navigation.addEventListener("navigate", async ({ destination, intercept }) => {
intercept(loadPhotoIntoCache(destination.url));
});
```
## URLPattern
You can match `destination.url` using [`URLPattern`](https://developer.mozilla.org/en-US/docs/Web/API/URL_Pattern_API)
```typescript
import {Navigation} from "@virtualstate/navigation";
import {URLPattern} from "urlpattern-polyfill";
const navigation = new Navigation();
navigation.addEventListener("navigate", async ({destination, intercept}) => {
const pattern = new URLPattern({ pathname: "/books/:id" });
const match = pattern.exec(destination.url);
if (match) {
intercept(transition());
}
async function transition() {
console.log("load book", match.pathname.groups.id)
}
});
navigation.navigate("/book/1");
```
## State
```typescript
import { Navigation } from "@virtualstate/navigation";
const navigation = new Navigation();
navigation.addEventListener("currententrychange", () => {
console.log({ updatedState: navigation.currentEntry?.getState() });
});
await navigation.updateCurrentEntry({
state: {
items: [
"first",
"second"
],
index: 0
}
}).finished;
await navigation.updateCurrentEntry({
state: {
...navigation.currentEntry.getState(),
index: 1
}
}).finished;
```
Polyfill Global Window Types
See [`@types/dom-navigation`](https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/dom-navigation/package.json) for a standardised type definition for the Navigation API
which can be utilised alongside this polyfill.
```bash
yarn add --dev @types/dom-navigation
```
This should then be included as a type in your `tsconfig.json`:
```json
{
"compilerOptions": {
"types": [
"dom-navigation"
]
}
}
```
Polyfill Serializer
You may want to set a custom serializer to store state in history
The default serializer is [JSON](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON)
In the past, a [structured clone like serializer](https://www.npmjs.com/package/@ungap/structured-clone) was used. This may be useful for you if
you're using native types rather than just JSON compatible values.
An example of making use of a custom serializer with the polyfill:
```typescript
import { setSerializer } from "@virtualstate/navigation/polyfill";
import { serialize, deserialize } from "@ungap/structured-clone";
setSerializer({
stringify(value) {
return serialize(value)
},
parse(value) {
return deserialize(value)
}
});
```
Change Log
- (1.0.1-alpha.206) Updated default serializer for polyfill to JSON [#35](https://github.com/virtualstate/navigation/pull/35)