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## :icon-list-unordered:  data_hash

---

`data_hash` plucks a hash of key-value pairs from the pagy object. It is useful for exporting pagination data to JavaScript frameworks like Vue.js, React.js, etc.

!!!success It works with all paginators
!!!

=== :icon-tools:  Usage

```ruby Controller
@pagy, @records = pagy(:offset, collection, **options)
pagy_hash       = @pagy.data_hash(data_keys: %i[page previous next previous_url next_url ...])
#=> { page: 3, previous: 2, next: 4, previous_url: ... }
render json: { data: @records, pagy: pagy_hash }
```

==- :icon-pin:  Examples

```ruby Console
require 'pagy/console'
=> true

>> @pagy, @records = pagy(:offset, collection.new, page: 3)
=> [#<Pagy::Offset:0x00007ff5843036e0 @count=1000, @from=41, @in=20, @in_range=true, @last=50, @limit=20, @next=4, @offset=40, @options={limit: 20, limit_key: "limit", page_key: "page", page: 3, count: 1000}, @page=3, @previous=2, @request=#<Pagy::Request:0x00007ff58497f230 @base_url="http://www.example.com", @cookie=nil, @jsonapi=nil, @path="/path", @params={example: "123"}>, @to=60>, [41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60]]

>> @pagy.data_hash(data_keys: %i[page previous next previous_url next_url])
=> {page: 3, previous: 2, next: 4, previous_url: "/path?example=123&page=2", next_url: "/path?example=123&page=4"}
```

==- :icon-sliders:&nbsp; Options

`data_keys = %i[...]`
: For efficiency, always set the `:data_keys` option to restrict the output to ONLY the keys you need among the default list:
  - `:count`
  - `:current_url`
  - `:first_url`
  - `:from`
  - `:in`
  - `:last`
  - `:last_url`
  - `:limit`
  - `:next`
  - `:next_url`
  - `:options`
  - `:page`
  - `:page_url` _(alias of :current_url)_
  - `:pages`
  - `:previous`
  - `:previous_url`
  - `:to`
  - `:url_template`

  Notice that you can also add other pagy method names not included in the default list (see [this discussion](https://github.com/ddnexus/pagy/discussions/812) for an example)

`absolute: true`
: Makes the URL absolute.

`path: '/my_path'`
: Overrides the request path in pagination URLs. Use the path only (not the absolute URL). _(see [Override the request path](/guides/how-to#paginate-multiple-independent-collections))_

`fragment: '...'`
: URL fragment string.

`querify: tweak`
: Set it to a `Lambda` to directly edit the passed string-keyed params hash itself. Its result is ignored.
  ```ruby
  tweak = ->(q) { q.except!('not_useful').merge!('custom' => 'useful') }
  ```

==- :icon-tools:&nbsp; Usage of `:url_template`

This is a URL string containing the `"P "` page token as a placeholder for the page value.

For example: `'/foo?page=P &bar=baz'`.

Replace it with JavaScript to generate the actual page URLs:

```javascript
pageUrl = url_template.replace("P ", '123')
// Result: '/foo?page=123&bar=baz'
```

!!!warning You may not need it for simple cases!
Consider using the available `:*_url` data_keys directly instead of relying on the `:url_template`.
!!!

===