Extract MELS-style comma separated list to shared utility

This allows other UI components to use the same formatting for a long list.

src/components/views/elements/MemberEventListSummary.js

@@ -1,5 +1,6 @@
 /*
 Copyright 2016 OpenMarket Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -13,11 +14,13 @@ 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 PropTypes from 'prop-types';
 import sdk from '../../../index';
-const MemberAvatar = require('../avatars/MemberAvatar.js');
+import MemberAvatar from '../avatars/MemberAvatar';
 import { _t } from '../../../languageHandler';
+import { formatCommaSeparatedList } from '../../../utils/FormattingUtils';
 
 module.exports = React.createClass({
     displayName: 'MemberEventListSummary',
@@ -105,7 +108,7 @@ module.exports = React.createClass({
                 );
             });
 
-            const desc = this._renderCommaSeparatedList(descs);
+            const desc = formatCommaSeparatedList(descs);
 
             return _t('%(nameList)s %(transitionList)s', { nameList: nameList, transitionList: desc });
         });
@@ -132,7 +135,7 @@ module.exports = React.createClass({
      * included before "and [n] others".
      */
     _renderNameList: function(users) {
-        return this._renderCommaSeparatedList(users, this.props.summaryLength);
+        return formatCommaSeparatedList(users, this.props.summaryLength);
     },
 
     /**
@@ -283,35 +286,6 @@ module.exports = React.createClass({
         return res;
     },
 
-    /**
-     * Constructs a written English string representing `items`, with an optional limit on
-     * the number of items included in the result. If specified and if the length of
-     *`items` is greater than the limit, the string "and n others" will be appended onto
-     * the result.
-     * If `items` is empty, returns the empty string. If there is only one item, return
-     * it.
-     * @param {string[]} items the items to construct a string from.
-     * @param {number?} itemLimit the number by which to limit the list.
-     * @returns {string} a string constructed by joining `items` with a comma between each
-     * item, but with the last item appended as " and [lastItem]".
-     */
-    _renderCommaSeparatedList(items, itemLimit) {
-        const remaining = itemLimit === undefined ? 0 : Math.max(
-            items.length - itemLimit, 0,
-        );
-        if (items.length === 0) {
-            return "";
-        } else if (items.length === 1) {
-            return items[0];
-        } else if (remaining > 0) {
-            items = items.slice(0, itemLimit);
-            return _t("%(items)s and %(count)s others", { items: items.join(', '), count: remaining } );
-        } else {
-            const lastItem = items.pop();
-            return _t("%(items)s and %(lastItem)s", { items: items.join(', '), lastItem: lastItem });
-        }
-    },
-
     _renderAvatars: function(roomMembers) {
         const avatars = roomMembers.slice(0, this.props.avatarsMaxLength).map((m) => {
             return (

src/i18n/strings/en_EN.json

@@ -253,6 +253,9 @@
     "This homeserver has exceeded one of its resource limits.": "This homeserver has exceeded one of its resource limits.",
     "Please <a>contact your service administrator</a> to continue using the service.": "Please <a>contact your service administrator</a> to continue using the service.",
     "Unable to connect to Homeserver. Retrying...": "Unable to connect to Homeserver. Retrying...",
+    "%(items)s and %(count)s others|other": "%(items)s and %(count)s others",
+    "%(items)s and %(count)s others|one": "%(items)s and one other",
+    "%(items)s and %(lastItem)s": "%(items)s and %(lastItem)s",
     "Your browser does not support the required cryptography extensions": "Your browser does not support the required cryptography extensions",
     "Not a valid Riot keyfile": "Not a valid Riot keyfile",
     "Authentication check failed: incorrect password?": "Authentication check failed: incorrect password?",
@@ -1046,9 +1049,6 @@
     "%(severalUsers)schanged their avatar %(count)s times|one": "%(severalUsers)schanged their avatar",
     "%(oneUser)schanged their avatar %(count)s times|other": "%(oneUser)schanged their avatar %(count)s times",
     "%(oneUser)schanged their avatar %(count)s times|one": "%(oneUser)schanged their avatar",
-    "%(items)s and %(count)s others|other": "%(items)s and %(count)s others",
-    "%(items)s and %(count)s others|one": "%(items)s and one other",
-    "%(items)s and %(lastItem)s": "%(items)s and %(lastItem)s",
     "collapse": "collapse",
     "expand": "expand",
     "Power level": "Power level",

src/utils/FormattingUtils.js

@@ -1,5 +1,6 @@
 /*
 Copyright 2016 OpenMarket Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -14,6 +15,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import { _t } from '../languageHandler';
+
 /**
  * formats numbers to fit into ~3 characters, suitable for badge counts
  * e.g: 999, 9.9K, 99K, 0.9M, 9.9M, 99M, 0.9B, 9.9B
@@ -63,3 +66,31 @@ export function getUserNameColorClass(userId) {
     const colorNumber = (hashCode(userId) % 8) + 1;
     return `mx_Username_color${colorNumber}`;
 }
+
+/**
+ * Constructs a written English string representing `items`, with an optional
+ * limit on the number of items included in the result. If specified and if the
+ * length of `items` is greater than the limit, the string "and n others" will
+ * be appended onto the result. If `items` is empty, returns the empty string.
+ * If there is only one item, return it.
+ * @param {string[]} items the items to construct a string from.
+ * @param {number?} itemLimit the number by which to limit the list.
+ * @returns {string} a string constructed by joining `items` with a comma
+ * between each item, but with the last item appended as " and [lastItem]".
+ */
+export function formatCommaSeparatedList(items, itemLimit) {
+    const remaining = itemLimit === undefined ? 0 : Math.max(
+        items.length - itemLimit, 0,
+    );
+    if (items.length === 0) {
+        return "";
+    } else if (items.length === 1) {
+        return items[0];
+    } else if (remaining > 0) {
+        items = items.slice(0, itemLimit);
+        return _t("%(items)s and %(count)s others", { items: items.join(', '), count: remaining } );
+    } else {
+        const lastItem = items.pop();
+        return _t("%(items)s and %(lastItem)s", { items: items.join(', '), lastItem: lastItem });
+    }
+}