module ietf-yang-push {

    yang-version 1;

    namespace
      "urn:ietf:params:xml:ns:yang:ietf-yang-push";

    prefix yp;

    import ietf-inet-types {
      prefix inet;
    }
    import ietf-yang-types {
      prefix yang;
    }
    import ietf-event-notifications {
      prefix notif-bis;
    }

    organization "IETF";

    contact
      "WG Web:   <http://tools.ietf.org/wg/netconf/>
       WG List:  <mailto:netconf@ietf.org>

       WG Chair: Mahesh Jethanandani
                 <mailto:mjethanandani@gmail.com>

       WG Chair: Mehmet Ersue
                 <mailto:mehmet.ersue@nokia.com>

       Editor:   Alexander Clemm
                 <mailto:alex@sympotech.com>

       Editor:   Eric Voit
                 <mailto:evoit@cisco.com>

       Editor:   Alberto Gonzalez Prieto
                 <mailto:albertgo@cisco.com>

       Editor:   Ambika Prasad Tripathy
                 <mailto:ambtripa@cisco.com>

       Editor:   Einar Nilsen-Nygaard
                 <mailto:einarnn@cisco.com>

       Editor:   Andy Bierman
                 <mailto:andy@yumaworks.com>

       Editor:   Balazs Lengyel
                 <mailto:balazs.lengyel@ericsson.com>";

    description
      "This module contains conceptual YANG specifications
       for YANG push.";

    revision "2021-03-01" {
      description
        "Correct datastore-*-string to datastore-*-xml";
    }

    revision "2016-10-28" {
      description
        "Updates to simplify modify-subscription, add anchor-time";
      reference
        "YANG Datastore Push, draft-ietf-netconf-yang-push-04";

    }


    feature on-change {
      description
        "This feature indicates that on-change updates are
         supported.";
    }

    identity error-data-not-authorized {
      base notif-bis:error;
      description
        "No read authorization for a requested data node.";
    }

    identity yang-push {
      base notif-bis:stream;
      description
        "A conceptual datastream consisting of all datastore
         updates, including operational and configuration data.";
    }

    identity custom-stream {
      base notif-bis:stream;
      description
        "A conceptual datastream for datastore
         updates with custom updates as defined by a user.";
    }

    identity http2 {
      base notif-bis:transport;
      description
        "HTTP2 notifications as a transport";
    }

    typedef filter-id {
      type uint32;
      description
        "A type to identify filters which can be associated with a
         subscription.";
    }

    typedef change-type {
      type enumeration {
        enum "create" {
          value 0;
          description
            "A new data node was created";
        }
        enum "delete" {
          value 1;
          description
            "A data node was deleted";
        }
        enum "modify" {
          value 2;
          description
            "The value of a data node has changed";
        }
      }
      description
        "Specifies different types of changes that may occur
         to a datastore.";
    }

    notification push-update {
      description
        "This notification contains a push update, containing
         data subscribed to via a subscription.
         This notification is sent for periodic updates, for a
         periodic subscription.  It can also be used for
         synchronization updates of an on-change subscription.
         This notification shall only be sent to receivers
         of a subscription; it does not constitute a general-purpose
         notification.";
      leaf subscription-id {
        type notif-bis:subscription-id;
        mandatory true;
        description
          "This references the subscription because of which the
           notification is sent.";
      }

      leaf time-of-update {
        type yang:date-and-time;
        description
          "This leaf contains the time of the update.";
      }

      leaf updates-not-sent {
        type empty;
        description
          "This is a flag which indicates that not all data nodes
           subscribed to are included included with this
           update.  In other words, the publisher has failed to
           fulfill its full subscription obligations.
           This may lead to intermittent loss of synchronization
           of data at the client.  Synchronization at the client
           can occur when the next push-update is received.";
      }

      anyxml datastore-contents-xml {
        description
          "This contains the updated data.  It constitutes a snapshot
           at the time-of-update of the set of data that has been
           subscribed to.  The format and syntax of the data
           corresponds to the format and syntax of data that would be
           returned in a corresponding get operation with the same
           filter parameters applied.";
      }
    }  // notification push-update

    notification push-change-update {
      if-feature on-change;
      description
        "This notification contains an on-change push update.
         This notification shall only be sent to the receivers
         of a subscription; it does not constitute a general-purpose
         notification.";
      leaf subscription-id {
        type notif-bis:subscription-id;
        mandatory true;
        description
          "This references the subscription because of which the
           notification is sent.";
      }

      leaf time-of-update {
        type yang:date-and-time;
        description
          "This leaf contains the time of the update, i.e. the
           time at which the change was observed.";
      }

      leaf updates-not-sent {
        type empty;
        description
          "This is a flag which indicates that not all changes which
           have occured since the last update are included with this
           update.  In other words, the publisher has failed to
           fulfill its full subscription obligations, for example in
           cases where it was not able to keep up with a change burst.
           To facilitate synchronization, a publisher MAY subsequently
           send a push-update containing a full snapshot of subscribed
           data. Such a push-update might also be triggered by a
           subscriber requesting an on-demand synchronization.";
      }

      anyxml datastore-changes-xml {
        description
          "This contains datastore contents that has changed
           since the previous update, per the terms of the
           subscription.  Changes are encoded analogous to
           the syntax of a corresponding yang-patch operation,
           i.e. a yang-patch operation applied to the YANG datastore
           implied by the previous update to result in the current
           state (and assuming yang-patch could also be applied to
           operational data).";
      }
    }  // notification push-change-update
  }  // module ietf-yang-push