events: Replace Captions with MessageContent

Use a custom serde implementation

crates/ruma-common/src/events/image.rs

@@ -8,7 +8,7 @@ use serde::{Deserialize, Serialize};
 
 use super::{
     file::{EncryptedContent, FileContent},
-    message::{MessageContent, Text},
+    message::MessageContent,
     room::message::Relation,
 };
 use crate::MxcUri;
@@ -35,8 +35,13 @@ pub struct ImageEventContent {
     pub thumbnail: Vec<ThumbnailContent>,
 
     /// The captions of the message.
-    #[serde(rename = "m.caption", default, skip_serializing_if = "Captions::is_empty")]
+    #[serde(
-    pub caption: Captions,
+        rename = "m.caption",
+        with = "super::message::content_serde::as_vec",
+        default,
+        skip_serializing_if = "Option::is_none"
+    )]
+    pub caption: Option<MessageContent>,
 
     /// Information about related messages for [rich replies].
     ///
@@ -151,71 +156,6 @@ impl ThumbnailContent {
     }
 }
 
-/// An array of captions.
-#[derive(Clone, Debug, Default, Serialize, Deserialize)]
-pub struct Captions(pub(crate) Vec<Text>);
-
-impl Captions {
-    /// Creates a new `Captions` with the given captions.
-    ///
-    /// The captions must be ordered by most preferred first.
-    pub fn new(captions: &[Text]) -> Self {
-        Self(captions.to_owned())
-    }
-
-    /// A convenience constructor to create a plain text caption.
-    pub fn plain(body: impl Into<String>) -> Self {
-        Self(vec![Text::plain(body)])
-    }
-
-    /// A convenience constructor to create an HTML caption.
-    pub fn html(body: impl Into<String>, html_body: impl Into<String>) -> Self {
-        Self(vec![Text::html(html_body), Text::plain(body)])
-    }
-
-    /// A convenience constructor to create a Markdown caption.
-    ///
-    /// Returns an HTML caption if some Markdown formatting was detected, otherwise returns a plain
-    /// text caption.
-    #[cfg(feature = "markdown")]
-    pub fn markdown(body: impl AsRef<str> + Into<String>) -> Self {
-        let mut message = Vec::with_capacity(2);
-        if let Some(html_body) = Text::markdown(&body) {
-            message.push(html_body);
-        }
-        message.push(Text::plain(body));
-        Self(message)
-    }
-
-    /// Get the captions.
-    ///
-    /// The captions are ordered by most preferred first.
-    pub fn captions(&self) -> &[Text] {
-        &self.0
-    }
-
-    /// Whether this is empty.
-    pub fn is_empty(&self) -> bool {
-        self.0.is_empty()
-    }
-
-    /// Get the plain text representation of this caption.
-    pub fn find_plain(&self) -> Option<&str> {
-        self.captions()
-            .iter()
-            .find(|content| content.mimetype == "text/plain")
-            .map(|content| content.body.as_ref())
-    }
-
-    /// Get the HTML representation of this caption.
-    pub fn find_html(&self) -> Option<&str> {
-        self.captions()
-            .iter()
-            .find(|content| content.mimetype == "text/html")
-            .map(|content| content.body.as_ref())
-    }
-}
-
 /// Image content.
 #[derive(Default, Clone, Debug, Serialize, Deserialize)]
 #[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]

crates/ruma-common/src/events/message.rs

@@ -52,7 +52,7 @@ use std::ops::Deref;
 use ruma_macros::EventContent;
 use serde::{Deserialize, Serialize};
 
-mod content_serde;
+pub(crate) mod content_serde;
 
 use content_serde::MessageContentSerDeHelper;
 

crates/ruma-common/src/events/message/content_serde.rs

@@ -67,3 +67,34 @@ impl Serialize for MessageContent {
         st.end()
     }
 }
+
+pub(crate) mod as_vec {
+    use serde::{ser::SerializeSeq, Deserialize, Deserializer, Serializer};
+
+    use crate::events::message::{MessageContent, Text};
+
+    /// Serializes a `Option<MessageContent>` as a `Vec<Text>`.
+    pub fn serialize<S>(content: &Option<MessageContent>, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        if let Some(content) = content {
+            let mut seq = serializer.serialize_seq(Some(content.len()))?;
+            for e in content.iter() {
+                seq.serialize_element(e)?;
+            }
+            seq.end()
+        } else {
+            serializer.serialize_seq(Some(0))?.end()
+        }
+    }
+
+    /// Deserializes a `Vec<Text>` to an `Option<MessageContent>`.
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Option<MessageContent>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        Option::<Vec<Text>>::deserialize(deserializer)
+            .map(|content| content.filter(|content| !content.is_empty()).map(Into::into))
+    }
+}

crates/ruma-common/src/events/video.rs

@@ -9,10 +9,7 @@ use ruma_macros::EventContent;
 use serde::{Deserialize, Serialize};
 
 use super::{
-    file::FileContent,
+    file::FileContent, image::ThumbnailContent, message::MessageContent, room::message::Relation,
-    image::{Captions, ThumbnailContent},
-    message::MessageContent,
-    room::message::Relation,
 };
 
 /// The payload for an extensible video message.
@@ -37,8 +34,13 @@ pub struct VideoEventContent {
     pub thumbnail: Vec<ThumbnailContent>,
 
     /// The captions of the message.
-    #[serde(rename = "m.caption", default, skip_serializing_if = "Captions::is_empty")]
+    #[serde(
-    pub caption: Captions,
+        rename = "m.caption",
+        with = "super::message::content_serde::as_vec",
+        default,
+        skip_serializing_if = "Option::is_none"
+    )]
+    pub caption: Option<MessageContent>,
 
     /// Information about related messages.
     #[serde(flatten, skip_serializing_if = "Option::is_none")]

crates/ruma-common/tests/events/image.rs

@@ -8,7 +8,7 @@ use ruma_common::{
     events::{
         file::{EncryptedContentInit, FileContent, FileContentInfo},
         image::{
-            Captions, ImageContent, ImageEventContent, ThumbnailContent, ThumbnailFileContent,
+            ImageContent, ImageEventContent, ThumbnailContent, ThumbnailFileContent,
             ThumbnailFileContentInfo,
         },
         message::MessageContent,
@@ -128,7 +128,7 @@ fn image_event_serialization() {
                     ),
                     None
                 )],
-                caption: Captions::plain("This is my house"),
+                caption: Some(MessageContent::plain("This is my house")),
                 relates_to: Some(Relation::Reply {
                     in_reply_to: InReplyTo::new(event_id!("$replyevent:example.com").to_owned()),
                 }),
@@ -207,7 +207,7 @@ fn plain_content_deserialization() {
     assert_matches!(
         from_json_value::<ImageEventContent>(json_data)
             .unwrap(),
-        ImageEventContent { message, file, image, thumbnail, caption, .. }
+        ImageEventContent { message, file, image, thumbnail, caption: Some(caption), .. }
         if message.find_plain() == Some("Upload: my_cat.png")
             && message.find_html().is_none()
             && file.url == "mxc://notareal.hs/abcdef"
@@ -248,7 +248,7 @@ fn encrypted_content_deserialization() {
     assert_matches!(
         from_json_value::<ImageEventContent>(json_data)
             .unwrap(),
-        ImageEventContent { message, file, image, thumbnail, caption, .. }
+        ImageEventContent { message, file, image, thumbnail, caption: None, .. }
         if message.find_plain() == Some("Upload: my_file.txt")
             && message.find_html().is_none()
             && file.url == "mxc://notareal.hs/abcdef"
@@ -256,7 +256,6 @@ fn encrypted_content_deserialization() {
             && image.width.is_none()
             && image.height.is_none()
             && thumbnail[0].file.url == "mxc://notareal.hs/thumbnail"
-            && caption.is_empty()
     );
 }
 
@@ -295,7 +294,7 @@ fn message_event_deserialization() {
                 },
                 image,
                 thumbnail,
-                caption,
+                caption: None,
                 ..
             },
             event_id,
@@ -313,7 +312,6 @@ fn message_event_deserialization() {
             && image.width == Some(uint!(1300))
             && image.height == Some(uint!(837))
             && thumbnail.is_empty()
-            && caption.is_empty()
             && origin_server_ts == MilliSecondsSinceUnixEpoch(uint!(134_829_848))
             && room_id == room_id!("!roomid:notareal.hs")
             && sender == user_id!("@user:notareal.hs")

crates/ruma-common/tests/events/video.rs

@@ -9,7 +9,7 @@ use ruma_common::{
     event_id,
     events::{
         file::{EncryptedContentInit, FileContent, FileContentInfo},
-        image::{Captions, ThumbnailContent, ThumbnailFileContent, ThumbnailFileContentInfo},
+        image::{ThumbnailContent, ThumbnailFileContent, ThumbnailFileContentInfo},
         message::MessageContent,
         room::{
             message::{InReplyTo, Relation},
@@ -135,7 +135,7 @@ fn event_serialization() {
                     ),
                     None
                 )],
-                caption: Captions::plain("This is my awesome vintage lava lamp"),
+                caption: Some(MessageContent::plain("This is my awesome vintage lava lamp")),
                 relates_to: Some(Relation::Reply {
                     in_reply_to: InReplyTo::new(event_id!("$replyevent:example.com").to_owned()),
                 }),
@@ -215,7 +215,7 @@ fn plain_content_deserialization() {
     assert_matches!(
         from_json_value::<VideoEventContent>(json_data)
             .unwrap(),
-        VideoEventContent { message, file, video, thumbnail, caption, .. }
+        VideoEventContent { message, file, video, thumbnail, caption: Some(caption), .. }
         if message.find_plain() == Some("Video: my_cat.mp4")
             && message.find_html().is_none()
             && file.url == "mxc://notareal.hs/abcdef"
@@ -257,7 +257,7 @@ fn encrypted_content_deserialization() {
     assert_matches!(
         from_json_value::<VideoEventContent>(json_data)
             .unwrap(),
-        VideoEventContent { message, file, video, thumbnail, caption, .. }
+        VideoEventContent { message, file, video, thumbnail, caption: None, .. }
         if message.find_plain() == Some("Upload: my_cat.mp4")
             && message.find_html().is_none()
             && file.url == "mxc://notareal.hs/abcdef"
@@ -266,7 +266,6 @@ fn encrypted_content_deserialization() {
             && video.height.is_none()
             && video.duration.is_none()
             && thumbnail[0].file.url == "mxc://notareal.hs/thumbnail"
-            && caption.is_empty()
     );
 }
 
@@ -305,7 +304,7 @@ fn message_event_deserialization() {
                 },
                 video,
                 thumbnail,
-                caption,
+                caption: None,
                 ..
             },
             event_id,
@@ -324,7 +323,6 @@ fn message_event_deserialization() {
             && video.height == Some(uint!(837))
             && video.duration.is_none()
             && thumbnail.is_empty()
-            && caption.is_empty()
             && origin_server_ts == MilliSecondsSinceUnixEpoch(uint!(134_829_848))
             && room_id == room_id!("!roomid:notareal.hs")
             && sender == user_id!("@user:notareal.hs")