Welcome page, support $ssoUrl and $casUrl placeholders

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

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 +18,7 @@ import React from 'react';
 import * as sdk from '../../../index';
 import SdkConfig from '../../../SdkConfig';
 import AuthPage from "./AuthPage";
+import * as Matrix from "matrix-js-sdk";
 
 export default class Welcome extends React.PureComponent {
     render() {
@@ -33,11 +34,23 @@ 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 callbackUrl = this.getSSOCallbackUrl(tmpClient.getHomeserverUrl(), tmpClient.getIdentityServerUrl());
+
         return (
             <AuthPage>
                 <div className="mx_Welcome">
-                    <EmbeddedPage className="mx_WelcomePage"
+                    <EmbeddedPage
+                        className="mx_WelcomePage"
                         url={pageUrl}
+                        replaceMap={{
+                            "$ssoUrl": tmpClient.getSsoLoginUrl(callbackUrl.toString(), "sso"),
+                            "$casUrl": tmpClient.getSsoLoginUrl(callbackUrl.toString(), "cas"),
+                        }}
                     />
                     <LanguageSelector />
                 </div>