xmpp-parsers: Simplify PubSub Item using xso

Now that we can have a single arbitrary payload, we can derive FromXml
and AsXml on the Item.

parsers/src/pubsub/event.rs

@@ -4,20 +4,33 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+use xso::{AsXml, FromXml};
+
 use crate::data_forms::DataForm;
 use crate::date::DateTime;
 use crate::message::MessagePayload;
 use crate::ns;
-use crate::pubsub::{Item as PubSubItem, ItemId, NodeName, Subscription, SubscriptionId};
+use crate::pubsub::{ItemId, NodeName, Subscription, SubscriptionId};
 use jid::Jid;
 use minidom::Element;
 use xso::error::{Error, FromElementError};
 
-/// Event wrapper for a PubSub `<item/>`.
-#[derive(Debug, Clone, PartialEq)]
-pub struct Item(pub PubSubItem);
+/// An event item from a PubSub node.
+#[derive(FromXml, AsXml, Debug, Clone, PartialEq)]
+#[xml(namespace = ns::PUBSUB_EVENT, name = "item")]
+pub struct Item {
+    /// The identifier for this item, unique per node.
+    #[xml(attribute(default))]
+    pub id: Option<ItemId>,
 
-impl_pubsub_item!(Item, PUBSUB_EVENT);
+    /// The JID of the entity who published this item.
+    #[xml(attribute(default))]
+    pub publisher: Option<Jid>,
+
+    /// The payload of this item, in an arbitrary namespace.
+    #[xml(element(default))]
+    pub payload: Option<Element>,
+}
 
 /// Represents an event happening to a PubSub node.
 #[derive(Debug, Clone, PartialEq)]

parsers/src/pubsub/mod.rs

@@ -18,7 +18,6 @@ pub use self::event::PubSubEvent;
 pub use self::owner::PubSubOwner;
 pub use self::pubsub::PubSub;
 
-use jid::Jid;
 use minidom::Element;
 
 generate_id!(
@@ -77,33 +76,5 @@ generate_attribute!(
     }
 );
 
-/// An item from a PubSub node.
-#[derive(Debug, Clone, PartialEq)]
-pub struct Item {
-    /// The identifier for this item, unique per node.
-    pub id: Option<ItemId>,
-
-    /// The JID of the entity who published this item.
-    pub publisher: Option<Jid>,
-
-    /// The payload of this item, in an arbitrary namespace.
-    pub payload: Option<Element>,
-}
-
-impl Item {
-    /// Create a new item, accepting only payloads implementing `PubSubPayload`.
-    pub fn new<P: PubSubPayload>(
-        id: Option<ItemId>,
-        publisher: Option<Jid>,
-        payload: Option<P>,
-    ) -> Item {
-        Item {
-            id,
-            publisher,
-            payload: payload.map(Into::into),
-        }
-    }
-}
-
 /// This trait should be implemented on any element which can be included as a PubSub payload.
 pub trait PubSubPayload: TryFrom<Element> + Into<Element> {}

parsers/src/pubsub/pubsub.rs

@@ -14,7 +14,7 @@ use crate::data_forms::DataForm;
 use crate::iq::{IqGetPayload, IqResultPayload, IqSetPayload};
 use crate::ns;
 use crate::pubsub::{
-    AffiliationAttribute, Item as PubSubItem, NodeName, Subscription, SubscriptionId,
+    AffiliationAttribute, ItemId, NodeName, PubSubPayload, Subscription, SubscriptionId,
 };
 use jid::Jid;
 use minidom::Element;
@@ -111,11 +111,37 @@ impl Items {
     }
 }
 
-/// Response wrapper for a PubSub `<item/>`.
-#[derive(Debug, Clone, PartialEq)]
-pub struct Item(pub PubSubItem);
+/// A requested item from a PubSub node.
+#[derive(FromXml, AsXml, Debug, Clone, PartialEq)]
+#[xml(namespace = ns::PUBSUB, name = "item")]
+pub struct Item {
+    /// The identifier for this item, unique per node.
+    #[xml(attribute(default))]
+    pub id: Option<ItemId>,
 
-impl_pubsub_item!(Item, PUBSUB);
+    /// The JID of the entity who published this item.
+    #[xml(attribute(default))]
+    pub publisher: Option<Jid>,
+
+    /// The payload of this item, in an arbitrary namespace.
+    #[xml(element(default))]
+    pub payload: Option<Element>,
+}
+
+impl Item {
+    /// Create a new item, accepting only payloads implementing `PubSubPayload`.
+    pub fn new<P: PubSubPayload>(
+        id: Option<ItemId>,
+        publisher: Option<Jid>,
+        payload: Option<P>,
+    ) -> Item {
+        Item {
+            id,
+            publisher,
+            payload: payload.map(Into::into),
+        }
+    }
+}
 
 /// The options associated to a subscription request.
 #[derive(FromXml, AsXml, Debug, PartialEq, Clone)]