platform/README.md
2017-05-26 09:36:17 -04:00

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# paginate
[![version 1.0.0](https://img.shields.io/badge/pub-v1.0.0-brightgreen.svg)](https://pub.dartlang.org/packages/angel_paginate)
[![build status](https://travis-ci.org/angel-dart/paginate.svg)](https://travis-ci.org/angel-dart/paginate)
![coverage: 97%](https://img.shields.io/badge/coverage-97%25-green.svg)
Platform-agnostic pagination library, with custom support for the
[Angel framework](https://github.com/angel-dart/angel).
# Installation
In your `pubspec.yaml` file:
```yaml
dependencies:
angel_paginate: ^1.0.0
```
# Usage
This library exports a `Paginator<T>`, which can be used to efficiently produce
instances of `PaginationResult<T>`. Pagination results, when serialized to JSON, look like
this:
```json
{
"total" : 75,
"items_per_page" : 10,
"previous_page" : 3,
"current_page" : 4,
"next_page" : 5,
"start_index" : 30,
"end_index" : 39,
"data" : ["<items...>"]
}
```
Results can be parsed from Maps using the `PaginationResult<T>.fromMap` constructor, and
serialized via their `toJson()` method.
To create a paginator:
```dart
import 'package:angel_paginate/angel_paginate.dart';
main() {
var p = new Paginator(iterable);
// Get the current page (default: page 1)
var page = p.current;
print(page.total);
print(page.startIndex);
print(page.data); // The actual items on this page.
p.next(); // Advance a page
p.back(); // Back one page
p.goToPage(10); // Go to page number (1-based, not a 0-based index)
}
```
The entire Paginator API is documented, so check out the DartDocs.
Paginators by default cache paginations, to improve performance as you shift through pages.
This can be especially helpful in a client-side application where your UX involves a fast
response time, i.e. a search page.
## Use With Angel
Naturally, a library named `angel_paginate` has special provisions for the
[Angel framework](https://github.com/angel-dart/angel).
In `package:angel_paginate/server.dart`, a function called `paginate` generates
pagination service hooks for you. If the result of a hooked service event is an `Iterable`,
it will be paginated. This is convenient because it works with any data store, whether it
be MongoDB, RethinkDB, an in-memory store, or something else entirely.
```dart
configureServer(Angel app) {
var service = app.service('api/foo') as HookedService;
service.afterIndexed.listen(paginate(itemsPerPage: 10));
}
```
See `test/server_test.dart` for examples of usage with Angel.