extend SSO docs (#4154)

docs/core/login.component.md

@@ -269,7 +269,7 @@ export class MyCustomLogin {
 Note that if you do not call `event.preventDefault()` then the default behaviour 
 will execute _after_ your custom code has completed.
 
-### SSO login
+### Single Sign-On (SSO)
 
 #### Implicit Flow
 
@@ -277,9 +277,11 @@ If you used the host-setting component to enable SSO Oauth (or if you
 enabled the setting in `app.config.json`) then the [login component](../core/login.component.md) will show only a button to login:
 
 ```JSON
+{
+    "providers": "ECM",
     "authType" :"OAUTH",
     "oauth2": {
-      "host": "http://localhost:30081/auth/realms/myrealm",
+      "host": "<AUTH-SERVER>/auth/realms/alfresco",
       "clientId": "activiti",
       "scope": "openid",
       "secret": "",
@@ -287,7 +289,8 @@ enabled the setting in `app.config.json`) then the [login component](../core/log
       "silentLogin": false,
       "redirectUri": "/",
       "redirectUriLogout": "/logout"
-    },
+    }
+}
 ```
 
 ![Login component](../docassets/images/sso-login.png)
@@ -296,6 +299,44 @@ Note that if the `silentLogin` property in the `oauth2` configuration is set to
 then the login page will not be shown. Instead, the application will redirect
 automatically to the authorization server when the user is not logged-in
 
+#### Silent login
+
+You can also enable automatic redirection to OAuth provider
+by utilising the following properties:
+
+* silentLogin
+* redirectSilentIframeUri
+
+```json
+{
+  "providers": "ECM",
+  "authType": "OAUTH",
+  "oauth2": {
+    "host": "<AUTH-SERVER>/auth/realms/alfresco",
+    "clientId": "alfresco",
+    "scope": "openid",
+    "secret": "",
+    "implicitFlow": true,
+    "silentLogin": true,
+    "redirectSilentIframeUri": "/assets/silent-refresh.html",
+    "redirectUri": "/",
+    "redirectUriLogout": "/logout"
+  },
+```
+
+Please note that if you deploy the application to a virtual folder,
+for example `http://<ADDRESS>/my-app`, then `redirectSilentIframeUri`
+must contain the full URI value: 
+
+```json
+{
+    "redirectSilentIframeUri": "http://<ADDRESS>/my-app/assets/silent-refresh.html",
+}
+```
+
+> In the default ADF application configurations the `silent-refresh.html` file
+> gets automatically copied to the application output when building for production.
+
 ## See Also
 
 -   [Logout directive](logout.directive.md)