From b695dee7872aca5bd54096f4c47c4bb6f25b3154 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Commaille?= <zecakeh@tedomum.fr>
Date: Fri, 30 Sep 2022 21:49:48 +0200
Subject: [PATCH] client-api: Add support for dir parameter to /relations

According to MSC3715
---
 crates/ruma-client-api/CHANGELOG.md               |  1 +
 .../src/relations/get_relating_events.rs          | 15 ++++++++++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/crates/ruma-client-api/CHANGELOG.md b/crates/ruma-client-api/CHANGELOG.md
index 50241b44..30d396c1 100644
--- a/crates/ruma-client-api/CHANGELOG.md
+++ b/crates/ruma-client-api/CHANGELOG.md
@@ -15,6 +15,7 @@ Improvements:
   * The fields added to `RoomEventFilter` were removed by MSC3856
 * Add support for the threads list API (MSC3856 / Matrix 1.4)
 * Stabilize support for private read receipts
+* Add support for the pagination direction parameter to `/relations` (MSC3715 / Matrix 1.4)
 
 # 0.15.1
 
diff --git a/crates/ruma-client-api/src/relations/get_relating_events.rs b/crates/ruma-client-api/src/relations/get_relating_events.rs
index ad6ffc0d..52b6495d 100644
--- a/crates/ruma-client-api/src/relations/get_relating_events.rs
+++ b/crates/ruma-client-api/src/relations/get_relating_events.rs
@@ -10,6 +10,8 @@ pub mod v1 {
     use js_int::UInt;
     use ruma_common::{api::ruma_api, events::AnyMessageLikeEvent, serde::Raw, EventId, RoomId};
 
+    use crate::Direction;
+
     ruma_api! {
         metadata: {
             description: "Get the child events for a given parent event.",
@@ -35,8 +37,8 @@ pub mod v1 {
             ///
             /// If `None`, results start at the most recent topological event known to the server.
             ///
-            /// Can be a `next_batch` token from a previous call, or a returned  `start` token from
-            /// `/messages` or a `next_batch` token from `/sync`.
+            /// Can be a `next_batch` or `prev_batch` token from a previous call, or a returned
+            /// `start` token from `/messages` or a `next_batch` token from `/sync`.
             ///
             /// Note that when paginating the `from` token should be "after" the `to` token in
             /// terms of topological ordering, because it is only possible to paginate "backwards"
@@ -45,6 +47,13 @@ pub mod v1 {
             #[ruma_api(query)]
             pub from: Option<&'a str>,
 
+            /// The direction to return events from.
+            ///
+            /// Defaults to [`Direction::Backward`].
+            #[serde(default, skip_serializing_if = "ruma_common::serde::is_default")]
+            #[ruma_api(query)]
+            pub dir: Direction,
+
             /// The pagination token to stop returning results at.
             ///
             /// If `None`, results continue up to `limit` or until there are no more events.
@@ -96,7 +105,7 @@ pub mod v1 {
     impl<'a> Request<'a> {
         /// Creates a new `Request` with the given room ID and parent event ID.
         pub fn new(room_id: &'a RoomId, event_id: &'a EventId) -> Self {
-            Self { room_id, event_id, from: None, to: None, limit: None }
+            Self { room_id, event_id, dir: Direction::default(), from: None, to: None, limit: None }
         }
     }