Implement MSC4481

README.md

@@ -46,12 +46,21 @@ increase its availability and avoid tampering.
 
 The matrix.to URL scheme is
 
+| Entity type: | Example URL                                                         |
+|--------------|---------------------------------------------------------------------|
+| Rooms:       | <https://matrix.to/#/r/matrix:matrix.org>                             |
+| Rooms by ID: | <https://matrix.to/#/roomid/cURbafjkfsMDVwdRDQ:matrix.org>            |
+| Users:       | <https://matrix.to/#/u/matthew:matrix.org>                            |
+| Messages:    | <https://matrix.to/#/r/matrix:matrix.org/e/1448831580433WbpiJ:jki.re> |
+
+The legacy scheme is deprecated, but as follows
+
 | Entity type: | Example URL                                                       |
 |--------------|-------------------------------------------------------------------|
-| Rooms:       | https://matrix.to/#/#matrix:matrix.org                            |
-| Rooms by ID: | https://matrix.to/#/!cURbafjkfsMDVwdRDQ:matrix.org                |
-| Users:       | https://matrix.to/#/@matthew:matrix.org                           |
-| Messages:    | https://matrix.to/#/#matrix:matrix.org/$1448831580433WbpiJ:jki.re |
+| Rooms:       | <https://matrix.to/#/#matrix:matrix.org>                            |
+| Rooms by ID: | <https://matrix.to/#/!cURbafjkfsMDVwdRDQ:matrix.org>                |
+| Users:       | <https://matrix.to/#/@matthew:matrix.org>                           |
+| Messages:    | <https://matrix.to/#/#matrix:matrix.org/$1448831580433WbpiJ:jki.re> |
 
 The #/ component is mandatory and exists to avoid leaking the target URL to the
 server hosting matrix.to.

src/Link.js

@@ -17,10 +17,10 @@ limitations under the License.
 import {createEnum} from "./utils/enum.js";
 import {orderedUnique} from "./utils/unique.js";
 
-const ROOMALIAS_PATTERN = /^#([^:]*):(.+)$/;
-const ROOMID_PATTERN = /^!([^:]*)(:(.+))?$/; // As of room version 12, room IDs don't have domains
-const USERID_PATTERN = /^@([^:]+):(.+)$/;
-const EVENTID_PATTERN = /^$([^:]+):(.+)$/;
+const ROOMALIAS_PATTERN = /^(?:#|r\/)([^:]*):(.+)$/;
+const ROOMID_PATTERN = /^(?:!|roomid\/)([^:]*)(:(.+))?$/; // As of room version 12, room IDs don't have domains
+const USERID_PATTERN = /^(?:@|u\/)([^:]+):(.+)$/;
+const EVENTID_PATTERN = /^(?:$|e\/)([^:]+):(.+)$/;
 const GROUPID_PATTERN = /^\+([^:]+):(.+)$/;
 
 export const IdentifierKind = createEnum(
@@ -40,6 +40,16 @@ function asPrefix(identifierKind) {
     }
 }
 
+function asMSC4481Prefix(identifierKind) {
+    switch (identifierKind) {
+        case IdentifierKind.RoomId: return "roomid/";
+        case IdentifierKind.RoomAlias: return "r/";
+        case IdentifierKind.GroupId: return asPrefix(identifierKind);
+        case IdentifierKind.UserId: return "u/";
+        default: throw new Error("invalid id kind " + identifierKind);
+    }
+}
+
 function getWebInstanceMap(queryParams) {
     const prefix = "web-instance[";
     const postfix = "]";
@@ -111,7 +121,22 @@ export class Link {
             return null;
         }
         linkStr = linkStr.slice(2);
-        const [identifier, eventId] = linkStr.split("/");
+        const segments = linkStr.split("/");
+        let _1, identifier, _2, eventId;
+        if (/^(roomid|r|u)/.test(linkStr)) {
+            [_1, identifier, _2, eventId] = segments;
+            if (_1 === "roomid")
+                identifier = "!" + identifier;
+            else if (_1 === "r")
+                identifier = "#" + identifier;
+            else
+                identifier = "@" + identifier;
+
+            if (_2 === "e")
+                eventId = "$" + eventId;
+        } else {
+            [identifier, eventId] = segments;
+        }
 
         let viaServers = [];
         let clientId = null;
@@ -210,10 +235,11 @@ export class Link {
     }
 
     toFragment() {
+        const id = `/${asMSC4481Prefix(this.identifierKind)}${this.identifier.substring(1)}`;
         if (this.eventId) {
-            return `/${this.identifier}/${this.eventId}`;
+            return `${id}/e/${this.eventId.substring(1)}`;
         } else {
-            return `/${this.identifier}`;
+            return id;
         }
     }
 }

src/create/CreateLinkView.js

@@ -29,7 +29,7 @@ export class CreateLinkView extends TemplateView {
                     type: "text",
                     name: "identifier",
                     required: true,
-                    placeholder: "#room:example.com, @user:example.com",
+                    placeholder: "r/room:example.com, u/user:example.com",
                     onChange: evt => this._onIdentifierChange(evt)
                 })),
                 t.div(t.input({className: "primary fullwidth icon link", type: "submit", value: "Create link"}))
@@ -48,7 +48,7 @@ export class CreateLinkView extends TemplateView {
     _onIdentifierChange(evt) {
         const inputField = evt.target;
         if (!this.value.validateIdentifier(inputField.value)) {
-            inputField.setCustomValidity("That doesn't seem valid. Try #room:example.com, @user:example.com or +group:example.com.");
+            inputField.setCustomValidity("That doesn't seem valid. Try r/room:example.com, u/user:example.com or +group:example.com.");
         } else {
             inputField.setCustomValidity("");
         }

src/create/CreateLinkViewModel.js

@@ -30,7 +30,7 @@ export class CreateLinkViewModel extends ViewModel {
     }
 
     async createLink(identifier) {
-        this._link = Link.parseIdentifier(identifier);
+        this._link = Link.parseFragment(`#/${identifier}`);
         if (this._link) {
             this.openLink("#" + this._link.toFragment());
         }