Factor out shared logic in two code-paths for pill rendering

This isn't an entirely side-effect-free refactoring:
 - the text of the timeline pills is now either the room ID/alias or user ID/ display name of the linked resource (which means that until we do a roundtrip to get user displaynames, mentions for users not in the current room will have their user IDs shown instead of what was in the link body).
 - timeline links to rooms without avatars are now rendered as links
 - fixed issue that would throw an error whilst rendering (i.e. unusable client) a room link to a room that the client doesn't know about

src/components/views/elements/Pill.js

@@ -0,0 +1,118 @@
+/*
+Copyright 2017 Vector Creations Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+import React from 'react';
+import sdk from '../../../index';
+import classNames from 'classnames';
+import { Room, RoomMember } from 'matrix-js-sdk';
+import PropTypes from 'prop-types';
+import MatrixClientPeg from '../../../MatrixClientPeg';
+import { MATRIXTO_URL_PATTERN } from '../../../linkify-matrix';
+import { getDisplayAliasForRoom } from '../../../Rooms';
+
+const REGEX_MATRIXTO = new RegExp(MATRIXTO_URL_PATTERN);
+
+// For URLs of matrix.to links in the timeline which have been reformatted by
+// HttpUtils transformTags to relative links
+const REGEX_LOCAL_MATRIXTO = /^#\/(?:user|room)\/(([\#\!\@\+]).*)$/;
+
+export default React.createClass({
+    statics: {
+        isPillUrl: (url) => {
+            return !!REGEX_MATRIXTO.exec(url);
+        },
+        isMessagePillUrl: (url) => {
+            return !!REGEX_LOCAL_MATRIXTO.exec(url);
+        },
+    },
+
+    props: {
+        // The URL to pillify (no validation is done, see isPillUrl and isMessagePillUrl)
+        url: PropTypes.string,
+        // Whether the pill is in a message
+        inMessage: PropTypes.bool,
+        // The room in which this pill is being rendered
+        room: PropTypes.instanceOf(Room),
+    },
+
+    render: function() {
+        const MemberAvatar = sdk.getComponent('avatars.MemberAvatar');
+        const RoomAvatar = sdk.getComponent('avatars.RoomAvatar');
+
+        let regex = REGEX_MATRIXTO;
+        if (this.props.inMessage) {
+            regex = REGEX_LOCAL_MATRIXTO;
+        }
+
+        // Default to the empty array if no match for simplicity
+        // resource and prefix will be undefined instead of throwing
+        const matrixToMatch = regex.exec(this.props.url) || [];
+        console.info(matrixToMatch);
+
+        const resource = matrixToMatch[1]; // The room/user ID
+        const prefix = matrixToMatch[2]; // The first character of prefix
+
+        // Default to the room/user ID
+        let linkText = resource;
+
+        const isUserPill = prefix === '@';
+        const isRoomPill = prefix === '#' || prefix === '!';
+
+        let avatar = null;
+        let userId;
+        if (isUserPill) {
+            // If this user is not a member of this room, default to the empty member
+            // TODO: This could be improved by doing an async profile lookup
+            const member = this.props.room.getMember(resource) ||
+                new RoomMember(null, resource);
+            if (member) {
+                userId = member.userId;
+                linkText = member.name;
+                avatar = <MemberAvatar member={member} width={16} height={16}/>;
+            }
+        } else if (isRoomPill) {
+            const room = prefix === '#' ?
+                MatrixClientPeg.get().getRooms().find((r) => {
+                    return r.getAliases().includes(resource);
+                }) : MatrixClientPeg.get().getRoom(resource);
+
+            if (room) {
+                linkText = (room ? getDisplayAliasForRoom(room) : null) || resource;
+                avatar = <RoomAvatar room={room} width={16} height={16}/>;
+            }
+        }
+
+        const classes = classNames({
+            "mx_UserPill": isUserPill,
+            "mx_RoomPill": isRoomPill,
+            "mx_UserPill_me": userId === MatrixClientPeg.get().credentials.userId,
+        });
+
+        if ((isUserPill || isRoomPill) && avatar) {
+            return this.props.inMessage ?
+                <a className={classes} href={this.props.url}>
+                    {avatar}
+                    {linkText}
+                </a> :
+                <span className={classes}>
+                    {avatar}
+                    {linkText}
+                </span>;
+        } else {
+            // Deliberately render nothing if the URL isn't recognised
+            return null;
+        }
+    },
+});

src/components/views/messages/TextualBody.js

@@ -170,56 +170,21 @@ module.exports = React.createClass({
     },
 
     pillifyLinks: function(nodes) {
-        const MemberAvatar = sdk.getComponent('avatars.MemberAvatar');
-        const RoomAvatar = sdk.getComponent('avatars.RoomAvatar');
         for (let i = 0; i < nodes.length; i++) {
             const node = nodes[i];
             if (node.tagName === "A" && node.getAttribute("href")) {
                 const href = node.getAttribute("href");
-                // HtmlUtils transforms `matrix.to` links to local links, so match against
+
-                // user or room app links.
+                // If the link is a (localised) matrix.to link, replace it with a pill
-                const match = /^#\/(user|room)\/(.*)$/.exec(href) || [];
+                const Pill = sdk.getComponent('elements.Pill');
-                const resourceType = match[1]; // "user" or "room"
+                if (Pill.isMessagePillUrl(href)) {
-                const resourceId = match[2]; // user ID or room ID
+                    const pillContainer = document.createElement('span');
-                if (match && resourceType && resourceId) {
+
-                    let avatar;
+                    const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
-                    let roomId;
+                    const pill = <Pill url={href} inMessage={true} room={room}/>;
-                    let room;
+
-                    let member;
+                    ReactDOM.render(pill, pillContainer);
-                    let userId;
+                    node.parentNode.replaceChild(pillContainer, node);
-                    switch (resourceType) {
-                        case "user":
-                            roomId = this.props.mxEvent.getRoomId();
-                            room = MatrixClientPeg.get().getRoom(roomId);
-                            userId = resourceId;
-                            member = room.getMember(userId) ||
-                                new RoomMember(null, userId);
-                            avatar = <MemberAvatar member={member} width={16} height={16} name={userId}/>;
-                        break;
-                        case "room":
-                            room = resourceId[0] === '#' ?
-                                MatrixClientPeg.get().getRooms().find((r) => {
-                                    return r.getCanonicalAlias() === resourceId;
-                                }) : MatrixClientPeg.get().getRoom(resourceId);
-                            if (room) {
-                                avatar = <RoomAvatar room={room} width={16} height={16}/>;
-                            }
-                        break;
-                    }
-                    if (avatar) {
-                        const avatarContainer = document.createElement('span');
-                        node.className = classNames(
-                            "mx_MTextBody_pill",
-                            {
-                                "mx_UserPill": match[1] === "user",
-                                "mx_RoomPill": match[1] === "room",
-                                "mx_UserPill_me":
-                                    userId === MatrixClientPeg.get().credentials.userId,
-                            },
-                        );
-                        ReactDOM.render(avatar, avatarContainer);
-                        node.insertBefore(avatarContainer, node.firstChild);
-                    }
                 }
             } else if (node.children && node.children.length) {
                 this.pillifyLinks(node.children);

src/components/views/rooms/MessageComposerInput.js

@@ -26,7 +26,6 @@ import Promise from 'bluebird';
 
 import MatrixClientPeg from '../../../MatrixClientPeg';
 import type {MatrixClient} from 'matrix-js-sdk/lib/matrix';
-import {RoomMember} from 'matrix-js-sdk';
 import SlashCommands from '../../../SlashCommands';
 import KeyCode from '../../../KeyCode';
 import Modal from '../../../Modal';
@@ -43,10 +42,6 @@ import {Completion} from "../../../autocomplete/Autocompleter";
 import Markdown from '../../../Markdown';
 import ComposerHistoryManager from '../../../ComposerHistoryManager';
 import MessageComposerStore from '../../../stores/MessageComposerStore';
-import { getDisplayAliasForRoom } from '../../../Rooms';
-
-import {MATRIXTO_URL_PATTERN} from '../../../linkify-matrix';
-const REGEX_MATRIXTO = new RegExp(MATRIXTO_URL_PATTERN);
 
 import {asciiRegexp, shortnameToUnicode, emojioneList, asciiList, mapUnicodeToShort} from 'emojione';
 const EMOJI_SHORTNAMES = Object.keys(emojioneList);
@@ -188,56 +183,10 @@ export default class MessageComposerInput extends React.Component {
         decorators.push({
             strategy: this.findLinkEntities.bind(this),
             component: (props) => {
-                const MemberAvatar = sdk.getComponent('avatars.MemberAvatar');
+                const Pill = sdk.getComponent('elements.Pill');
-                const RoomAvatar = sdk.getComponent('avatars.RoomAvatar');
                 const {url} = Entity.get(props.entityKey).getData();
-
+                if (Pill.isPillUrl(url)) {
-                // Default to the empty array if no match for simplicity
+                    return <Pill url={url} room={this.props.room}/>;
-                // resource and prefix will be undefined instead of throwing
-                const matrixToMatch = REGEX_MATRIXTO.exec(url) || [];
-
-                const resource = matrixToMatch[1]; // The room/user ID
-                const prefix = matrixToMatch[2]; // The first character of prefix
-
-                // Default to the room/user ID
-                let linkText = resource;
-
-                const isUserPill = prefix === '@';
-                const isRoomPill = prefix === '#' || prefix === '!';
-
-                const classes = classNames({
-                    "mx_UserPill": isUserPill,
-                    "mx_RoomPill": isRoomPill,
-                });
-
-                let avatar = null;
-                if (isUserPill) {
-                    // If this user is not a member of this room, default to the empty
-                    // member. This could be improved by doing an async profile lookup.
-                    const member = this.props.room.getMember(resource) ||
-                        new RoomMember(null, resource);
-
-                    linkText = member.name;
-
-                    avatar = member ? <MemberAvatar member={member} width={16} height={16}/> : null;
-                } else if (isRoomPill) {
-                    const room = prefix === '#' ?
-                        MatrixClientPeg.get().getRooms().find((r) => {
-                            return r.getCanonicalAlias() === resource;
-                        }) : MatrixClientPeg.get().getRoom(resource);
-
-                    linkText = getDisplayAliasForRoom(room) || resource;
-
-                    avatar = room ? <RoomAvatar room={room} width={16} height={16}/> : null;
-                }
-
-                if (isUserPill || isRoomPill) {
-                    return (
-                        <span className={classes}>
-                            {avatar}
-                            {linkText}
-                        </span>
-                    );
                 }
 
                 return (