Support $riot: Templates for SSO/CAS urls in the welcome.html page

src/components/structures/EmbeddedPage.js

@@ -37,6 +37,8 @@ export default class EmbeddedPage extends React.PureComponent {
         className: PropTypes.string,
         // Whether to wrap the page in a scrollbar
         scrollbar: PropTypes.bool,
+        // Map of keys to replace with values, e.g {$placeholder: "value"}
+        replaceMap: PropTypes.object,
     };
 
     static contextType = MatrixClientContext;
@@ -81,6 +83,13 @@ export default class EmbeddedPage extends React.PureComponent {
                 }
 
                 body = body.replace(/_t\(['"]([\s\S]*?)['"]\)/mg, (match, g1)=>this.translate(g1));
+
+                if (this.props.replaceMap) {
+                    Object.keys(this.props.replaceMap).forEach(key => {
+                        body = body.split(key).join(this.props.replaceMap[key]);
+                    });
+                }
+
                 this.setState({ page: body });
             },
         );

src/components/structures/MatrixChat.js

@@ -2021,7 +2021,7 @@ export default createReactClass({
             }
         } else if (this.state.view === VIEWS.WELCOME) {
             const Welcome = sdk.getComponent('auth.Welcome');
-            view = <Welcome />;
+            view = <Welcome {...this.getServerProperties()} />;
         } else if (this.state.view === VIEWS.REGISTER) {
             const Registration = sdk.getComponent('structures.auth.Registration');
             view = (

src/components/views/auth/Welcome.js

@@ -18,6 +18,12 @@ import React from 'react';
 import * as sdk from '../../../index';
 import SdkConfig from '../../../SdkConfig';
 import AuthPage from "./AuthPage";
+import * as Matrix from "matrix-js-sdk";
+import {_td} from "../../../languageHandler";
+import PlatformPeg from "../../../PlatformPeg";
+
+// translatable strings for Welcome pages
+_td("Sign in with SSO");
 
 export default class Welcome extends React.PureComponent {
     render() {
@@ -33,11 +39,24 @@ export default class Welcome extends React.PureComponent {
             pageUrl = 'welcome.html';
         }
 
+        const {hsUrl, isUrl} = this.props.serverConfig;
+        const tmpClient = Matrix.createClient({
+            baseUrl: hsUrl,
+            idBaseUrl: isUrl,
+        });
+        const plaf = PlatformPeg.get();
+        const callbackUrl = plaf.getSSOCallbackUrl(tmpClient.getHomeserverUrl(), tmpClient.getIdentityServerUrl());
+
         return (
             <AuthPage>
                 <div className="mx_Welcome">
-                    <EmbeddedPage className="mx_WelcomePage"
+                    <EmbeddedPage
+                        className="mx_WelcomePage"
                         url={pageUrl}
+                        replaceMap={{
+                            "$riot:ssoUrl": tmpClient.getSsoLoginUrl(callbackUrl.toString(), "sso"),
+                            "$riot:casUrl": tmpClient.getSsoLoginUrl(callbackUrl.toString(), "cas"),
+                        }}
                     />
                     <LanguageSelector />
                 </div>

src/i18n/strings/en_EN.json

@@ -1870,6 +1870,7 @@
     "Find other public servers or use a custom server": "Find other public servers or use a custom server",
     "Sign in to your Matrix account on %(serverName)s": "Sign in to your Matrix account on %(serverName)s",
     "Sign in to your Matrix account on <underlinedServerName />": "Sign in to your Matrix account on <underlinedServerName />",
+    "Sign in with SSO": "Sign in with SSO",
     "Sorry, your browser is <b>not</b> able to run Riot.": "Sorry, your browser is <b>not</b> able to run Riot.",
     "Riot uses many advanced browser features, some of which are not available or experimental in your current browser.": "Riot uses many advanced browser features, some of which are not available or experimental in your current browser.",
     "Please install <chromeLink>Chrome</chromeLink>, <firefoxLink>Firefox</firefoxLink>, or <safariLink>Safari</safariLink> for the best experience.": "Please install <chromeLink>Chrome</chromeLink>, <firefoxLink>Firefox</firefoxLink>, or <safariLink>Safari</safariLink> for the best experience.",