Add server-side pagination to any list or table on the page. This directive connects a variable of your choice on the local scope with data provied on a given URL. It provides a pagination user interface that triggers updates to the variable through paginated AJAX requests.
Pagination is a distinct concern and should be handled separately from other app logic. Do it right, do it in one place. Paginate anything!
Include with bower
bower install angular-paginate-anything
Load the javascript and declare your Angular dependency
angular.module('myModule', ['begriffs.paginate-anything']);
Then in your view
<!-- elements such as an ng-table reading from someVariable -->
<begriffs.pagination
collection="someVariable"
url="'https://api.server.com/stuff'">
</begriffs.pagination>
The pagination
directive uses an external template stored in
tpl/paginate-anything.html
. Host it in a place accessible to
your page and set the template-url
attribute. Note that the url
param can be a scope variable as well as a hard-coded string.
- Attaches to anything — ng-repeat, ng-grid, ngTable etc
- Server side pagination scales to large data
- Works with any MIME type through RFC2616 Range headers
- Handles finite or infinite lists
- Negotiates per-page limits with server
- Keeps items in view when changing page size
- Twitter Bootstrap compatible markup
The directive emits events as pages load (pagination:loadPage
)
or errors occur (pagination:error
). To catch these events do the
following:
$scope.$on('pagination:loadPage', function (event, status, config) {
// config contains parameters of the page request
console.log(config.url);
// status is the HTTP status of the result
console.log(status);
});
Your server is responsible for interpreting URLs to provide these
features. You can connect the url
attribute of this directive
to a scope variable and adjust the variable with query params and
whatever else your server recognizes. Or you can use the url-params
attribute to connect a map of strings or objects which will be
turned to ?key1=value1&key2=value2 after the url. Changing the
url
or url-params
causes the pagination to reset to the first
page and maintain page size.
Example:
$scope.url = 'api/resources';
$scope.urlParams = {
key1: "value1",
key2: "value2"
};
Will turn into the URL of the resource that is being requested: api/resources?key1=value1&key2=value2
This directive decorates AJAX requests to your server with some simple, standard headers. You read these headers to determine the limit and offset of the requested data. Your need to set response headers to indicate the range returned and the total number of items in the collection.
You can write the logic yourself, or use one of the following server side libraries.
Framework | Solution |
---|---|
Ruby on Rails | begriffs/clean_pagination gem |
Node.js | node-paginate-anything module |
Express JS from scratch howto | |
ServiceStack for .NET | .NET howto |
For a reference of a properly configured server, visit pagination.begriffs.com.
Here is an example HTTP transaction that requests the first twenty-five items and a response that provides them and says there are one hundred total items.
Request
GET /items HTTP/1.1
Range-Unit: items
Range: 0-24
Response
HTTP/1.1 206 Partial Content
Accept-Ranges: items
Content-Range: 0-24/100
Range-Unit: items
Content-Type: application/json
[ etc, etc, ... ]
In short your server parses the Range
header to find the zero-based
start and end item. It includes a Content-Range
header in the
response disclosing the range it chooses to return, along with the
total items after a slash, where total items can be "*" meaning
unknown or infinite.
When there are zero elements to return your server should send
status code 204 (no content), Content-Range: */0
, and an empty
body.
To do all this header stuff you'll need to enable CORS on your server.
In a Rails app you can do this by adding the following to config/application.rb
:
config.middleware.use Rack::Cors do
allow do
origins '*'
resource '*',
:headers => :any,
:methods => [:get, :options],
:expose => ['Content-Range', 'Accept-Ranges']
end
end
For a more complete implementation including other appropriate responses see my clean_pagination gem.
- Hypertext Transfer Protocol (HTTP/1.1): Range Requests
- RFC2616 Section 3.12, custom range units
- Beyond HTTP Header Links
- Heroku recommends Range headers for pagination
Thanks to Steve Klabnik for discussions about doing hypermedia/HATEOAS right, and to Rebecca Wright for reviewing and improving my original user interface ideas for the paginator.