sklera - digital signage made easy

Websites can be added to your library starting with sklera standard, and be used in playlists and layouts.

General 

For the best experience we recommend placing websites within a layout. This enables you to fine tune the display of your website to your liking with the various options offered by the layout editor.

Cookie notifications

The cookie banners which grace most websites on your first visit can not be automatically removed by sklera. To remove these you have some options:

• Connect a mouse to the digital signage screen the website is being displayed on. Then confirm the cookie notification. This confirmation cookie will be set on your screen and will suppress the notification until the cookie lapses.
  
  
• If you're developing your own website or have administrative access: one option is to pass along an URL parameter which when used suppresses the notification. You can then add the website to your library with the URL including the suppression parameter.

Logins  / Automatic Logins

Some websites require you to log in with an account to access all functionality. Depending on the website this may take different approaches.

Supported by sklera:

• Manual login on your device. Connect a mouse and keyboard to the device displaying the website and manually log in with your credentials. The login session will remain active however long the website in question allows it.
  
  
• Login via HTTP Basic Auth: Some Websites enable you to do a login via Basic Auth, where you supply username and password as part of the URL:
  https://USERNAME:PASSWORD@theUrlWhereyouLogin.com
  Simply enter the entire URL including the credentials when adding your website to your library.
  
  
• Tokens or similar via URL Parameters: For some websites you'll be able to obtain a public URL where you can use the service with your account. This often takes the form of special URLS with an access token or something similar in the URL.
  Simply use this URL to add the website to the library.

Rendering Engines

Modern websites are optimized for display on fairly recent smartphones, tablets, laptops or PCs. This means that many of these websites use javascript or CSS features which only work in newer browser versions.

Digital Signage displays usually use the browser engines included in their firmware. These firmware browsers, most often using a variation of Chrome, are often woefully out of date and may or may not support the features required by your website. Your website may look broken, or not display at all.

Which specific rendering engine is used by your sklera player can be ascertained by going to the detail page of the player in the CMS and scroll to the bottom of the page. There you'll see the user agent, which will contain the Chromium version of your device.

Overview of common rendering engines on digital signage devices

Can I update the rendering engine on my device?

Normally the answer is no. Digital Signage Hardware most often bakes the rendering engine into their firmware, so any possible update of the rendering engine hinges on the manufacturer updating the chromium version in their firmware - which rarely happens.

The only player side alternative is to use external player hardware (like a Windows-, Linux- or Raspberry Pi based Electron player, which is currently bundled with Chromium 124). 

The Website shows no thumbnail in the sklera library

This means that the website was not accessible by the sklera CMS to create a screenshot. This may have different causes:

• You made a typo in the URL while adding the website. To fix this simply edit the website item in the library and correct the typo, or simply re-add the website to your library.
  
  
• The website is not accessible from the sklera CMS. This normally happens if you try to add an intranet page or a website in a segregated network not accessible from the outside.
  As long as the screens which should show the website have network access to its server they'll be displayed properly nonetheless.

The website is not showing on my device

Content Security Policy or x-frame-options

The operators of a website may restrict in their servers' configuration whether the website is allowed to be embedded in other domains or not. This happens via the HTTP headers which the server sends along with the website as it's being accessed.

• x-frame-options: this HTTP header may take the value 'DENY' or 'SAMEORIGIN', thus disabling the embedding of a website in sklera
• content-security-policy: part of this HTTP header may define the 'frame-ancestors', defining which domains may embed this website.

Websites with these headers will not show at all in the sklera CMS within the layout composer or many of the preview functions available throughout the CMS.

Most Digital Signage displays share these restrictions and will likely refuse to show the website, either silently or with an error message, depending on the manufacturer.

The exception to the rule are sklera players based on Electron (Windows, Linux, Raspberry Pi), which show up as regular web browsers and do not underlie this restriction.

Network connection

The sklera player devices directly connect to the website in question. This means the devices will need to have an active internet connection to access the resource, and the website needs to be reachable from the network of the device.

Firewalls

Digital Signage Displays for security reasons are often segregated into their own local network within the greater company, with special security rules. Firewalls may block access to the wider internet and thus the website in question - in these cases the websites need to be whitelisted.

HTTP / HTTPS, incorrect time settings

If a sklera player is paired to the CMS via HTTPS, but the website was added to the library via HTTP the player device may refuse to show the website as it considers the content insecure.

Often an incorrect system time on the device will lead to the device not trusting the SSL certificates of the website and refuse to display it.

(Incompatible) SSL certificates

Some older Digital Signage devices are not compatible with newer SSL certificates and may show a general network error, or a certificate specific error. Some devices may fix the compatibility issue with a firmware update.

Self Signed Certificates, as commonly used by larger organisations, may need to be manually added to the device hardware in their manufacturer settings.