Add @Mentions

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+- add @mentions
+  - new `Element::Mention{ address: &str }`
+  - new api `extract_mention_addresses` to extract
+
 ## 0.8.0 - Nom 7 and more Generic URI Schemes
 
 ### Changed

message_parser_wasm/example.html

@@ -36,6 +36,14 @@
         border-radius: 2px;
         padding: 2px;
       }
+
+      .mention {
+        color: rgb(0, 126, 168);
+      }
+
+      body {
+        font-family: sans-serif;
+      }
     </style>
     <h3>Input</h3>
     <textarea

message_parser_wasm/example.js

@@ -85,6 +85,15 @@ function renderElement(elm) {
       email.innerText = elm.c;
       email.href = "mailto:" + elm.c;
       return email;
+
+    case "Mention":
+      let mention = document.createElement("span");
+      mention.innerText = "@" + elm.c.address;
+      mention.onclick = () => {
+        alert(`Clicked on a Mention, this should open view profile view for ${elm.c.address}`)
+      }
+      mention.className = "mention"
+      return mention
 
     case "BotCommandSuggestion":
       let bcs = document.createElement("a");

message_parser_wasm/src/lib.rs

@@ -52,6 +52,7 @@ export type ParsedElement =
   | { t: "InlineCode"; c: { content: string } }
   | { t: "CodeBlock"; c: { language: null | string; content: string } }
   | { t: "EmailAddress"; c: string }
+  | { t: "Mention"; c: { address: string } }
   | { t: "BotCommandSuggestion"; c: string }
   | { t: "Link"; c: { destination: LinkDestination } }
   | {

message_parser_wasm/src/manual_typings.ts

@@ -20,6 +20,7 @@ export type ParsedElement =
   | { t: "InlineCode"; c: { content: string } }
   | { t: "CodeBlock"; c: { language: null | string; content: string } }
   | { t: "EmailAddress"; c: string }
+  | { t: "Mention"; c: { address: string } }
   | { t: "BotCommandSuggestion"; c: string }
   | { t: "Link"; c: { destination: LinkDestination } }
   | {

spec.md

@@ -6,6 +6,7 @@
 
 - Text only
   - [Email addresses: `[email protected]`](#email-addresses)
+  - [Mentions `@[email protected]`](#mentions)
   - [Links: `https://delta.chat` and `mailto:[email protected]`](#links)
   - [Bot `/commands`](#bot-commands)
   - [Hashtags: `#tag`](#hashtag)
@@ -34,6 +35,33 @@ Text elements that are displayed as is with no change to the content, just enhan
 
 Make email addresses clickable, opens the chat with that contact and creates it if it does not already exist.
 
+#### Format
+
+- format should follow standards (as time of writing the current implementation is still fairly dumb)
+- trailing `.` is not part of the email address and should not be parsed with it.
+
+<a name="mentions" id="mentions"></a>
+
+### Mentions `@[email protected]`
+
+Clickable mentions, opens profile view for a contact.
+UI may replace email address by display name
+and highlight it to distinguish it from normal text.
+(like other messengers do it, look at telegram, discord, element and so on)
+
+#### Format
+
+A valid email address preceded by an `@` character.
+Reuses parsing logic from [email address](#email-addresses).
+
+#### Other uses
+
+There will be a dedicated api that just extracts mentions from a text that will be used by deltachat core to be able to notify users when they are mentioned.
+
+#### In Message Composer
+
+the message input field should provide autocomletions as user types @Displayname or @[email protected]
+
 <a name="links" id="links"></a>
 
 ### `https://delta.chat` and `mailto:[email protected]` - Links
@@ -187,21 +215,7 @@ URL parsing allows all valid URLs, no restrictions on schemes, no whitelist is n
 
 - ':' + [A-z0-9_-] + ':' ?
 - could also be used for custom DC emojis in the future
-
-### Mentions `@username`
-
-Clickable. (could get replaced with a user hash/email/ID on send/on receive so that it's still valid on name change.)
-
-On sending/receiving, this is transformed into an internal representation:
-
-Implementation idea:
-
-1. user types @Displayname and at best gets autocompletion while typing the URL
-2. on sending, the username is converted to the transmission format (special format that contains the email address as ID)
-3. on receiving/storing the message inside the database, this format is converted again to contain the local contact ID to allow for future email address migration/rotation.
-   (4.) on forwarding/sharing as chat history, the ID representation needs to be converted from the contact ID format to the transmission format again
-
-see discords mention code for reference/inspiration https://blog.discordapp.com/how-discord-renders-rich-messages-on-the-android-app-67b0e5d56fbe
+- In Message Composer: should provide auto completions that replace the text by the unicode emoji, or the complete code if it is a custom emoji.
 
 ### `$[inline TeX]$` and `$$[Tex displayed in block(new line)]$$`
 

src/parser/mod.rs

@@ -22,10 +22,10 @@ pub enum Element<'a> {
         destination: LinkDestination<'a>,
     },
     EmailAddress(&'a str),
+    Mention {
+        address: &'a str,
+    },
     // Later:
-    // Mention {
-    //     internal_id: &str
-    // },
     /// On click, the command gets prefilled as the draft, so it can be easily send.
     BotCommandSuggestion(&'a str),
 
@@ -68,3 +68,8 @@ pub fn parse_only_text(input: &str) -> std::vec::Vec<Element> {
 pub fn parse_desktop_set(input: &str) -> std::vec::Vec<Element> {
     parse_from_text::parse_desktop_set(input)
 }
+
+/// Extract mentions as email addresses from a text
+pub fn extract_mention_addresses(input: &str) -> Vec<String> {
+    parse_from_text::extract_mention_addresses(input)
+}

src/parser/parse_from_text/mod.rs

@@ -1,3 +1,7 @@
+use nom::bytes::complete::take_until;
+
+use self::base_parsers::CustomError;
+
 use super::Element;
 
 pub(crate) mod base_parsers;
@@ -77,3 +81,26 @@ pub(crate) fn parse_desktop_set(input: &str) -> std::vec::Vec<Element> {
     }
     result
 }
+
+/// Extract mentions as email addresses from a text
+/// The addresses are sorted and deduplicated
+pub(crate) fn extract_mention_addresses(input: &str) -> Vec<String> {
+    let mut result = Vec::new();
+    let mut remaining = input;
+    while !remaining.is_empty() {
+        if let Ok((rest, Element::Mention { address })) = text_elements::mention(remaining) {
+            result.push(address.to_owned());
+            remaining = rest;
+            continue;
+        }
+        if let Ok((rest, _)) = take_until::<&str, &str, CustomError<&str>>(" @")(remaining) {
+            remaining = rest;
+        } else {
+            // there is no mention anymore in this message
+            break;
+        }
+    }
+    result.sort();
+    result.dedup();
+    result
+}

src/parser/parse_from_text/text_elements.rs

@@ -94,6 +94,18 @@ pub(crate) fn email_address(input: &str) -> IResult<&str, Element, CustomError<&
     }
 }
 
+pub(crate) fn mention(input: &str) -> IResult<&str, Element, CustomError<&str>> {
+    let (input, _) = tag("@")(input)?;
+    let (input, email) = email_address(input)?;
+    if let Element::EmailAddress(address) = email {
+        Ok((input, Element::Mention { address }))
+    } else {
+        Err(nom::Err::Error(CustomError::UnxepectedError(
+            "no email, should not happen".to_string(),
+        )))
+    }
+}
+
 fn not_link_part_char(c: char) -> bool {
     !matches!(c, ':' | '\n' | '\r' | '\t' | ' ')
 }
@@ -263,6 +275,8 @@ pub(crate) fn parse_text_element(
 
     if let Ok((i, elm)) = hashtag(input) {
         Ok((i, elm))
+    } else if let Ok((i, elm)) = mention(input) {
+        Ok((i, elm))
     } else if let Ok((i, elm)) = email_address(input) {
         Ok((i, elm))
     } else if let Ok((i, elm)) = link(input) {

tests/mentions.rs

@@ -0,0 +1,29 @@
+use deltachat_message_parser::parser::extract_mention_addresses;
+
+#[test]
+fn extract_mentions() {
+    let mention_text = "Ping @[email protected] and @[email protected]!";
+    assert_eq!(
+        extract_mention_addresses(mention_text),
+        vec!["[email protected]", "[email protected]"]
+    )
+}
+
+#[test]
+fn extract_mentions_are_deduped_and_sorted() {
+    let mention_text =
+        "Ping @[email protected], @[email protected], @[email protected] and @[email protected]!\n@[email protected] your opinion would be especially helpful.";
+    assert_eq!(
+        extract_mention_addresses(mention_text),
+        vec!["[email protected]", "[email protected]", "[email protected]"]
+    )
+}
+
+#[test]
+fn extract_mentions_false_positive() {
+    let mention_text = "my text@[email protected], more text";
+    assert_eq!(
+        extract_mention_addresses(mention_text),
+        Vec::<String>::new()
+    );
+}

tests/test.rs

@@ -1 +1,2 @@
 mod text_to_ast;
+mod mentions;

tests/text_to_ast/text_only.rs

@@ -271,6 +271,89 @@ fn email_address_do_not_parse_last_char_if_special() {
     );
 }
 
+#[test]
+fn mention_example() {
+    assert_eq!(
+        parse_only_text("This is not very easy.\n Please ask @[email protected]"),
+        vec![
+            Text("This is not very easy."),
+            Linebreak,
+            Text(" Please ask "),
+            Mention {
+                address: "[email protected]"
+            },
+        ]
+    );
+}
+
+#[test]
+fn mention_do_not_parse_last_dot() {
+    assert_eq!(
+        parse_only_text("you can ping me like this @[email protected]."),
+        vec![
+            Text("you can ping me like this "),
+            Mention {
+                address: "[email protected]"
+            },
+            Text(".")
+        ]
+    );
+}
+
+#[test]
+fn mention_do_not_parse_last_char_if_special() {
+    assert_eq!(
+        parse_only_text("you can ping me via @[email protected]!"),
+        vec![
+            Text("you can ping me via "),
+            Mention {
+                address: "[email protected]"
+            },
+            Text("!")
+        ]
+    );
+    assert_eq!(
+        parse_only_text("you can ping me via @[email protected]?"),
+        vec![
+            Text("you can ping me via "),
+            Mention {
+                address: "[email protected]"
+            },
+            Text("?")
+        ]
+    );
+    assert_eq!(
+        parse_only_text("you can ping me via @[email protected],"),
+        vec![
+            Text("you can ping me via "),
+            Mention {
+                address: "[email protected]"
+            },
+            Text(",")
+        ]
+    );
+    assert_eq!(
+        parse_only_text("you can ping me via @[email protected]:"),
+        vec![
+            Text("you can ping me via "),
+            Mention {
+                address: "[email protected]"
+            },
+            Text(":")
+        ]
+    );
+    assert_eq!(
+        parse_only_text("you can ping me via @[email protected];"),
+        vec![
+            Text("you can ping me via "),
+            Mention {
+                address: "[email protected]"
+            },
+            Text(";")
+        ]
+    );
+}
+
 #[test]
 fn link() {
     let test_cases = vec![