angularjs-rails-resource | A resource factory inspired by resource from AngularJS | REST library

Snapshots allow you to save off the state of the resource at a specific point in time and if need be roll back to one of the saved snapshots and yes, you can create as many snapshots as you want. Snapshots serialize the resource instance and save off a copy of the serialized data in the $$snapshots array on the instance. If you use a custom serialization options to control what is sent to the server you may want to consider whether or not you want to use different serialization options. If so, you can specify an specific serializer for snapshots using the snapshotSerializer configuration option. Calling save, create, update, or delete/remove on a resource instance will remove all snapshots when the operation completes successfully. Creating a snapshot is easy, just call the snapshot function. You can pass an optional callback function to snapshot to perform additional custom operations after the rollback is complete. The callback function is specific to each snapshot version created so make sure you pass it every time if it's a callback you always want called.
snapshotSerializer (optional) - Allows specifying a custom serializer to configure custom serialization options specific to snapshot and rollback.
Deserialize the snapshot data and update the resource instance with the new data.
Remove all snapshots newer than the version being rolled back to.
Call the rollback callback if it was specified on the snapshot in the context of the resource instance.
When numVersions is undefined or 0 then a single version is rolled back.
When numVersions exceeds the stored number of snapshots then the resource is rolled back to the first snapshot version.
When numVersions is less than 0 then the resource is rolled back to the first snapshot version.
Otherwise, numVersions represents the nth version from the last snapshot version (similar to calling rollback numVersions times).
When snapshotVersion is greater than the number of versions then the last snapshot version will be used.
When snapshotVersion is less than 0 then the resource will be rolled back to the first version.
Otherwise, the resource will be rolled back to the specific version specified.
If there are no snapshots, returns true
If all properties considered by angular.equals match the latest snapshot, returns false; otherwise, returns true
(Note that angular.equals does not consider $-prefixed properties)