Web Launcher & Web Start
As previously communicated, Oracle announced the end-of-life of Java SE 8 (Standard Edition). Free public updates for commercial users are no longer available. Customers accessing Niagara with the Java Applet/Web Start are impacted by this change. Those who have upgraded to full HTML5 versions for your browser front-end will not be affected. For customers who use the Java VM and Java Web Start for their legacy systems, Tridium has developed a suitable alternative, the Niagara Web Launcher.
The Niagara Web Launcher is now available for download. You can download the Niagara Web Launcher using the following links.
- 64-bit systems: https://weblauncher.niagara-central.com/NiagaraWebLauncher.msi
- (-x86) systems: https://weblauncher.niagara-central.com/NiagaraWebLauncher-x86.msiNiagara
- Web Launcher application is also available for download from the Niagara Station login page for Niagara versions that are configured to enable Niagara Web Launcher.
Niagara Web Launcher support is included with the following builds:
- 4.4U3 - Included in (4.4.94.14). Release notes found here
- 4.7U1 - Included in (4.7.110.32). Release notes found here
- File name: web.jar
- File version: 3.8.403.1
Downloading the Installer
When you initiate a browser connection to the station the pre-login window provides a link under the login dialog that reads: “To connect using Niagara Web Launcher click here”. Clicking this link downloads and auto-runs the installer file.
NOTE: If the installer does not automatically run. Access the NiagaraWebLauncher*.msi file in your browser’s downloads location and double-click the file to run the setup wizard shown below. You may notice another file, <stationName>.nwl is downloaded to the same location. This is a text file containing information that tells Web Launcher how to connect to that particular station. So, on subsequent connections, there is no need to download and run the *.msi installer file again. Instead, you could double-click the *.nwl file which launches webLauncher.exe.Once the installer launches the Niagara Web Launcher Setup Wizard, you can close the browser, or you can go to a different web page while the setup wizard runs and installs the executable file.
Installing Web Launcher
The installer file (NiagaraWebLauncher*.msi) which should auto-run upon downloading, opens the Niagara Web Launcher Setup window. The setup wizard runs and installs the Web Launcher executable file.
Step 1
As with most installer wizards, on-screen instructions in the windows walk you through the installation process. Click Next to advance to the next window, Back to see a previous window, Install to begin the
installation, and on completion click Finish to exit the installer. Click Cancel to exit without completing the installation.
When the installer finishes, if the Launch Niagara Web Launcher check box is selected it automatically launches the Niagara Web Launcher application in a separate window.
Step 2
In the Niagara Web Launcher window, first you are prompted to enter a Station URL, then your Username, and Password credentials to connect to the station.
Once the Web Launcher executable file is installed you only need to run webLauncher.exe to connect to the station. There is no longer any need to access the login page via a browser or to run the installer file again. Optionally, you can create a Windows shortcut for the webLauncher.exe file to use on subsequent connections.
NOTE: You can configure Web Launcher to open with a connection to a station in one of two ways:
- Edit the host address in the Web Launcher <stationName>.nwl file (in your browser’s downloads loca-tion) by opening the file using a text editor, and replace the host address with your preferred hostaddress.
- Launch Web Launcher from the command line by entering: weblauncher.exe host=https://localhost.
NOTE: The installer also installs webLauncher_debug.exe (in the same location as the Web Launcher executable) which you can run if you need debugging information. Double-clicking the file to opens a Debug window and a Web Launcher window.
Web Launcher Limitations
Known limitations of the Web Launcher implementation in Niagara are described here.
When the Niagara Web Launcher application creates the Workbench view, that view is not contained within a web page. The view has no direct relationship to HTML elements in a web page, and the HTML does notknow about the view. The view is not displayed as part of the layout of a page. This means that certain thingsthat might have been possible with the applet in a browser will not work in Web Launcher. An applet con-tained withinan HTML frame, for instance, cannot be supported in Niagara Web Launcher.
An Hx view containing an instance of the applet may not display in a browser exactly as it did in a previous release(s). The Niagara Web Launcher application is unable to display the applet in-line with the HTML content. Instead, the application positions the HTML and applet next to each other. The application shows the Hx path bar at the top of the view, with the applet below it. HTML content below the applet is not visible.
Using Java Web Start
The Niagara Web Start feature provides an applet-like Workbench environment that runs completely outside of the browser.
NOTE: In Niagara 4.4 and later, by default Web Launcher and Web Start can no longer be used to navigate to arbitrary Web addresses. The only way to directly load URLs is by first configuring a whitelist in the station's defaults/system.properties file. For example, if your station includes Px pages that include embedded WebBrowsers to external URLs, or hyperlinks to external URLs, then you must configure the whitelist to allow Web Launcher/Web Start to load those URLs. For more details, see “Configuring the web browser whitelist” in Getting Started with Niagara.
NOTE: Oracle has announced the pending end-of-life of Java SE 8 (Standard Edition). As of January 2019, free public updates are no longer available. Customers accessing Niagara with the Java Applet/Web Start will be impacted by this change as they will no longer receive free security updates to their Java installation from Oracle. Customers who have upgraded to full HTML5 versions for their browser front-end will not be affected. For customers who use the Java VM and Java Web Start for their legacy systems, Tridium has developed a suitable alternative and those users can begin utilizing the Niagara alternative, Niagara Web Launcher.
The web browser is needed only to download a JNLP file that is used to launch the application. The downloaded JNLP file can be used to launch the application on subsequent occasions (the browser is notneeded again). The
Niagara Web Start application then checks that a Java 8 JRE is installed, as a minimum. It does not check the update release version of the installed JRE.
In the figure shown here, you would launch the application by clicking the additional link under the login dialog that reads: “To connect using Java Web Start clickhere”. Of course, if you configure Web Start desktop or Start menu shortcuts, Workbench is launched from those. In that case, the link and login page in the web browser are not used. Once the application is downloaded and launched, you can close the browser or you can go to a different web page while the application continues running.
A significant advantage that Workbench launched by this method has over launching as a browser applet is that it overcomes typical compatibility problems with browsers' Java plugins. For example, many late version browsers have disabled support for NPAPI which prevents the Java WbApplet from running in the browser.
Optionally, the Java Web Start application can be branded. You may add brand icons for the window frame and shortcuts. For example, an OEM distributing the Niagara-based application can configure the brand.properties file with their brand defaults, and a Systems Integrator installing that product can optionally modify the default shortcut text to suit the end users via the configuration properties available in the station’s Web Services.
Enabled by default, to use Web Start simply decide whether or not you want to install application shortcuts. If you do, use the Web Start Config properties (in the station’s Web Services) to enable the shortcuts and modify default shortcut text as needed.
About JNLP Files
Java Web Start applications are launched using the Java Network Launch Protocol (JNLP). The JNLP file is required in order to deploy an application. A web browser is needed only to download a JNLP file that is used to launch the application. On subsequent occasions, you can double-click the JNLP file to relaunch the application. The web browser is not needed. The JNLP file, which is generated by the web server, is an XML text file that describes how the application should be launched. It contains the basic information on the application and host, such as the URL of the hosting station. The file does not contain any user- or session-specific information.
NOTE: Once a JNLP file is obtained, the application then checks that a Java 8 JRE (at a minimum) is in-stalled. However, it does not check the update release version of the installed JRE.
NOTE: If using the Chrome web browser, Chrome is not able to automatically open a JNLP file. The file must first be downloaded and then opened manually.
You may see the following notification that the required JRE unlimited strength policy files must be installed. After the files are installed, you must close the application and restart it.
NOTE: If you have difficulty starting the Web Start application it may be due to the presence of a self-signed server certificate in the station.
Web Start Config Properties
Web Start Config is a slot in the Web Services Property Sheet view. The Web Start Config properties permit you to enable/disable Web Start functionality and to configure shortcuts.
Web Start Config Property Descriptions
Default Web Profile Properties
The Default Web Profile, in the station’s UserService, includes two Web Start configuration options as well: Show Web Start Address Bar and Show Web Start Status Bar. The new profile options allow profile users to hide those parts of the window if they don’t want to see them.
Enabling Web Start
Typically, Web Start functionality is enabled by default. However, if needed, you can enable it via the station’s WebServices Property Sheet view, as described in this procedure. Step 1
On the station’s WebServices Property Sheet view, expand the Web Start Config slot (as shown) and click on the Web Start Enabled dropdown to set the value to true.
Step 2
Click Save.
Web Start functionality is enabled on the station. Optionally, you can click in the text field for the App Title property to modify the text that displays with the Start menu or desktop shortcuts. Typically, the default app title would be the station name, server name, IP address or localhost.
Configuring Web Start Shortcuts
Java Web Start properties allow you to configure the application to launch from a desktop shortcut or a Start Menu shortcut. Note that configuring shortcuts is optional, it is not required.
Step 1
On the station’s WebServices PropertySheetview, expand the Web Start Config slot and click on the dropdown list to enable the following shortcut properties:
- Create Start Menu Shortcut
- Create Desktop Shortcut
Step 2
If desired, click in the text field for the Shortcut Folder Name property to modify the default text field for the shortcut. This step is optional.
NOTE: For security reasons, this property supports only a few of the BFormat options:
- %server% - the host name or IP address of the station. This is the URL used to get the JNLP file.
- %station% - the station name.
- %app% - the application name. This value is from the webstart.title property in the brand.properties file or if not specified there, it defaults to the value configured for the Web Start Config App Title property.
- %vendor% - the vendor name. This value is from the webstart.vendor property in the brand.properties file properties file or if not specified there, it is the license brand by default.
About Multi-Station Navigation
Multi-station navigation functions somewhat differently in a Java Web Start application than it does in the applet.
When navigating a system, if a login page for another station is encountered, the page may show a link to open a new instance of the Web Start application. If the station you are navigating to has a different Niagara version, you can click the link to open a new Web Start instance, which will be launched from and use the modules from the other station. This requires Web Start to be supported and enabled on that other station.
NOTE: The AX Web Start application cannot open an applet view from the N4 station, and vice versa. In this situation, you must open the Web Start application from the other station.Web Start Limitations
Known limitations of the Web Start implementation in Niagara are described here.
When the Web Start application creates the Workbench view, that view is not contained within a web page. The view has no direct relationship to HTML elements in a web page, and the HTML does not know about the view. The view is not displayed as part of the layout of a page. This means that certain things that might have been possible with the applet in a browser will not work in Web Start. An applet contained within an HTML frame, for instance, cannot be supported in Web Start.
An Hx view containing an instance of the applet may not display in a browser exactly as it did in a previous release(s). The Web Start application is unable to display the applet in-line with the HTML content. Instead, the application positions the HTML and applet next to each other. The application shows the Hx path bar at tthe top of the view, with the applet below it. HTML content below the applet is not visible.
Additionally, the AX Web Start application cannot open an applet view from the Niagara 4 station, and vice versa. In this situation, you must open the Web Start application from the other station.
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