Add utm_campaign to the hosting links

According to where in the app the link was clicked

src/components/structures/GroupView.js

@@ -21,7 +21,7 @@ import Promise from 'bluebird';
 import MatrixClientPeg from '../../MatrixClientPeg';
 import sdk from '../../index';
 import dis from '../../dispatcher';
-import SdkConfig from '../../SdkConfig';
+import { getHostingLink } from '../../utils/HostingLink';
 import { sanitizedHtmlNode } from '../../HtmlUtils';
 import { _t, _td } from '../../languageHandler';
 import AccessibleButton from '../views/elements/AccessibleButton';
@@ -818,7 +818,7 @@ export default React.createClass({
 
         const header = this.state.editing ? <h2> { _t('Community Settings') } </h2> : <div />;
 
-        const hostingSignupLink = SdkConfig.get().hosting_signup_link;
+        const hostingSignupLink = getHostingLink('community-settings');
         let hostingSignup = null;
         if (hostingSignupLink) {
             hostingSignup = <div className="mx_GroupView_hostingSignup">

src/components/views/context_menus/TopLeftMenu.js

@@ -21,6 +21,7 @@ import { _t } from '../../../languageHandler';
 import LogoutDialog from "../dialogs/LogoutDialog";
 import Modal from "../../../Modal";
 import SdkConfig from '../../../SdkConfig';
+import { getHostingLink } from '../../../utils/HostingLink';
 import MatrixClientPeg from '../../../MatrixClientPeg';
 
 export class TopLeftMenu extends React.Component {
@@ -53,7 +54,7 @@ export class TopLeftMenu extends React.Component {
     render() {
         const isGuest = MatrixClientPeg.get().isGuest();
 
-        const hostingSignupLink = SdkConfig.get().hosting_signup_link;
+        const hostingSignupLink = getHostingLink('user-context-menu');
         let hostingSignup = null;
         if (hostingSignupLink) {
             hostingSignup = <div className="mx_TopLeftMenu_upgradeLink">

src/components/views/settings/ProfileSettings.js

@@ -21,7 +21,7 @@ import Field from "../elements/Field";
 import AccessibleButton from "../elements/AccessibleButton";
 import classNames from 'classnames';
 import {User} from "matrix-js-sdk";
-import SdkConfig from '../../../SdkConfig';
+import { getHostingLink } from '../../../utils/HostingLink';
 
 export default class ProfileSettings extends React.Component {
     constructor() {
@@ -131,7 +131,7 @@ export default class ProfileSettings extends React.Component {
             </div>
         );
 
-        const hostingSignupLink = SdkConfig.get().hosting_signup_link;
+        const hostingSignupLink = getHostingLink('user-settings');
         let hostingSignup = null;
         if (hostingSignupLink) {
             hostingSignup = <span className="mx_ProfileSettings_hostingSignup">

src/utils/HostingLink.js

@@ -0,0 +1,37 @@
+/*
+Copyright 2019 New Vector 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 url from 'url';
+import qs from 'qs';
+
+import SdkConfig from '../SdkConfig';
+
+export function getHostingLink(campaign) {
+    const hostingLink = SdkConfig.get().hosting_signup_link;
+    if (!hostingLink) return null;
+    if (!campaign) return hostingLink;
+
+    try {
+        const hostingUrl = url.parse(hostingLink);
+        const params = qs.parse(hostingUrl.query);
+        params.utm_campaign = campaign;
+        hostingUrl.search = undefined;
+        hostingUrl.query = params;
+        return hostingUrl.format();
+    } catch (e) {
+        return hostingLink;
+    }
+}