---
description: Learn how use Angular bindings for the Triplit client in your app.
---

import { Tabs, Tab, Callout } from 'nextra-theme-docs';
import CreateTriplitAppTabs from '../../components/CreateTriplitAppTabs.mdx';

# Angular

### New projects

The fast way to get started with Triplit is to use Create Triplit App which will scaffold a Angular application with Triplit. Choose `Angular` when prompted for the frontend framework.

<CreateTriplitAppTabs />

### Existing projects

If have an existing Angular project, you install the hooks provided by `@triplit/angular`:

<Tabs items={['npm', 'pnpm', 'yarn', 'bun']}>

  <Tab>
    ```bash copy
    npm i @triplit/angular
    ```
  </Tab>
    <Tab>
    ```bash copy
    pnpm add @triplit/angular
    ```
  </Tab>
  <Tab>
    ```bash copy
    yarn add @triplit/angular
    ```
  </Tab>
    <Tab>
    ```bash copy
    bun add @triplit/angular
    ```
  </Tab>
</Tabs>

## Signal-based hooks

### injectQuery

The `injectQuery` hook subscribes to the provided query inside your Angular component and will automatically unsubscribe from the query when the component unmounts.

The result of the hook is an object with the following `Signal` properties:

- `results`: An array of entities that satisfy the query.
- `fetching`: A boolean that will be `true` initially, and then turn `false` when either the local fetch returns cached results or if there were no cached results and the remote fetch has completed.
- `fetchingLocal`: A boolean indicating whether the query is currently fetching from the local cache.
- `fetchingRemote`: A boolean indicating whether the query is currently fetching from the server.
- `error`: An error object if the query failed to fetch.

```ts filename="app.component.ts"
import { triplit } from '@/triplit/client.js';
import { injectQuery } from '@triplit/angular';
import { Component, computed } from '@angular/core';
import { TodoComponent } from './todo/todo.component.js';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [TodoComponent],
  template: `
    <div>
      @if (queryResults.fetching()) {
        <p>Loading...</p>
      }
      @if (queryResults.results()) {
        <div>
          @for (todo of queryResults.results(); track todo.id) {
            <app-todo [todo]="todo" />
          }
        </div>
      }
    </div>
  `,
})
export class AppComponent {
  queryResults = injectQuery(() => ({
    client: triplit,
    query: triplit.query('todos').order('created_at', 'DESC'),
  }));
}
```

### injectConnectionStatus

The `injectConnectionStatus` hook subscribes to changes to the connection status of the client and will automatically unsubscribe when the component unmounts.

```ts filename="connection-status.component.ts"
import { Component } from '@angular/core';
import { injectConnectionStatus } from '@triplit/angular';
import { triplit } from '../../../triplit/client.js';

@Component({
  selector: 'app-connection-status',
  standalone: true,
  template: `<div>
    <div class="{{ 'indicator ' + status().toLowerCase() }}"></div>
    @if (status() === 'CLOSED') {
      Offline
    } @else if (status() === 'CONNECTING') {
      Connecting
    } @else {
      Online
    }
  </div>`,
})
export class ConnectionStatusComponent {
  status = injectConnectionStatus(triplit);
}
```

## Observable-based hooks

### createQuery

The `createQuery` hook return an object with observable properties that contain the results of the query, fetching states and error states. It has the same properties as the `injectQuery` hook, but the properties are `Observable` values instead of `Signal` values.

```ts filename="app.component.ts"
import { triplit } from '@/triplit/client.js';
import { createQuery } from '@triplit/angular';
import { Component } from '@angular/core';
import { CommonModule } from '@angular/common';
import { TodoComponent } from './todo/todo.component.js';
import { map } from 'rxjs';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [TodoComponent, CommonModule],
  template: `
    <div>
      @if (queryResults.fetching$ | async) {
        <p>Loading...</p>
      } @else {
        <div>
          @for (todo of queryResults.results$ | async; track todo.id) {
            <app-todo [todo]="todo" />
          }
        </div>
      }
    </div>
  `,
})
export class AppComponent {
  queryResults = createQuery(() => ({
    client: triplit,
    query: triplit.query('todos').order('created_at', 'DESC'),
  }));
}
```

### createInfiniteQuery

The `createInfiniteQuery` hook is similar to `createQuery`, but it is used for expanding queries, that is, queries that start with an initial limit but grow beyond that. It returns an object with observable properties that contain the results of the query, fetching states and error states, if there are more available results, and a function to load more data. It's important to define a `limit` in the query to enable the initial pagination.

```ts filename="app.component.ts"
import { triplit } from '@/triplit/client.js';
import { createInfiniteQuery } from '@triplit/angular';
import { Component } from '@angular/core';
import { CommonModule } from '@angular/common';
import { TodoComponent } from './todo/todo.component.js';
import { map } from 'rxjs';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [TodoComponent, CommonModule],
  template: `
    <div>
      @if (infiniteQuery.fetching$ | async) {
        <p>Loading...</p>
      } @else {
        <div class="todos-container">
          @for (todo of infiniteQuery.results$ | async; track todo.id) {
            <app-todo [todo]="todo" />
          }
        </div>
        <button
          [disabled]="!(infiniteQuery.hasMore$ | async)"
          (click)="infiniteQuery.loadMore(5)"
        >
          Load More
        </button>
      }
    </div>
  `,
})
export class AppComponent {
  infiniteQuery = createInfiniteQuery(() => ({
    client: triplit,
    query: triplit.query('todos').order('created_at', 'DESC').limit(5),
  }));
}
```

### createPaginatedQuery

The `createPaginatedQuery` hook is similar to `createQuery`, but it is used for paginated queries. It returns an object with observable properties that contain the results of the query, fetching states and error states, and functions to load the previous and next pages of data. It's important to define a `limit` in the query to enable pagination.

```ts filename="app.component.ts"
import { triplit } from '@/triplit/client.js';
import { createPaginatedQuery } from '@triplit/angular';
import { Component } from '@angular/core';
import { CommonModule } from '@angular/common';
import { TodoComponent } from './todo/todo.component.js';
import { map } from 'rxjs';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [TodoComponent, CommonModule],
  template: `
    <div>
      @if (paginatedQuery.fetching$ | async) {
        <p>Loading...</p>
      } @else {
        <div class="todos-container">
          @for (todo of paginatedQuery.results$ | async; track todo.id) {
            <app-todo [todo]="todo" />
          }
        </div>
        <button
          [disabled]="!(paginatedQuery.hasNextPage$ | async)"
          (click)="paginatedQuery.nextPage()"
        >
          Next page
        </button>
        <button
          [disabled]="!(paginatedQuery.hasPreviousPage$ | async)"
          (click)="paginatedQuery.prevPage()"
        >
          Previous page
        </button>
      }
    </div>
  `,
})
export class AppComponent {
  paginatedQuery = createPaginatedQuery(() => ({
    client: triplit,
    query: triplit.query('todos').order('created_at', 'DESC').limit(5),
  }));
}
```
