Web Client

Web Clients are one of the ways to deploy Solutions to end users.

Web Client is a browser-based application of which the  UI is rendered in the browser using pure HTML, CSS and a bit of JavaScript for event handling and communication with the Servoy Application Server. The  business logic of the Solution that is running in the Web Client is executed on the Application Server for security reasons: the code of the business logic is not exposed in the webpage markup. 

Supported browsers

The Servoy Web Client runs in the last few versions of all modern browsers, like Mozilla FireFox, Safari, Google Chrome and Internet Explorer.

Internet Explorer support is split, depending on the use of anchors:

• IE7 or higher if anchoring enabled
• IE6 or higher if anchoring is disabled

See the .... setting for more info on using anchors.

Starting Servoy Web Clients

Servoy Web Clients run in a browser and can be started by accessing a URL on the Servoy Application Server.

{serverUrl}/servoy-webclient/ss?s={solutionName}&m={methodName}&a={value}&{param1}={value1}&{param2}={value2}

Browser sessions

Running Servoy Web Client inside a Frame or IFrame

By default, a Web Client runs in the main browser window, but it is possible to run the Web Client inside a Frame/IFrame embedded in another webpage.

When running a Web Client inside an Frame or IFrame (here onwards just called frame) and the domain of the page into which the frame is embedded (for example: http://www.mycompany.com/pagewithframes.html) does not equal the domain from which the Web Client is hosted (for example http://mycompany.hostingcompany.com), there is a possible issue with the ability of storing HTTP Cookies.

Based on the settings of the browser, these so-called Third Party Cookies are blocked from storage. Internet Explorer does this by default, most other browsers allow it by default, but this can be turned off by the user.

The Web Client uses HTTP Cookies to save the position and location of dialogs and the functions application.setUserProperty(...) and application.getUserProperty(...) also utilize Cookies for string the User Property value. If the cookies cannot be stored, the Web client will continue to operate, but the position and sized of the dialogs and the value of User Properties will not be remembered.

The only remedy to the issue is configuring the browser to accept Third Party Cookies and this needs to be done by the user. As Internet Explorer does not allow Third Party Cookies by default, this browser is usually the one that causes Problems. Luckily, for Internet Explorer there is something that can be done by the developer of the webpage that is being displayed in the frame.

Adding a "Compact Privacy Policy" header to the Web Client pages
A Compact Privicy policy header is a specific header in the HTTP Response of a Web Client page, with a compact description of a Platform for Privacy Preferences (P3P) policy.

P3P is a standard for websites to provide the users of the website with information about the usage and possible storage of privacy related data. See http://www.w3.org/P3P/ for more information. Although the standard never really took off and isn't widely supported, it will come in handy in this scenario as Internet Explorer does implement it.

A P3P policy can be created online using http://p3pedit.com/ or with a downloadable tool provided by IBM here. When generated, it will also produce the Compact Privacy Policy string required for the configuration below.

Having said all of the above, many sites skip the generation of a full P3P policy and just take a appropriate value from the many websites that discuss the use of third party cookies in Internet Explorer and move on. The description of the required configuration below uses such a value, but we encourage developers/admins to set it up properly.

The P3P Compact Privacy Policy header can be added to all Web Client pages served by the Application Server, by adding and configuring a Filter in the webserver used by the Servoy Application Server.

The Filter is a small Java library and can be downloaded here: FilterP3P.jar. Place the downloaded jar file in <serverUrl>/application_server/server/webapps/ROOT/WEB-INF/lib (create the lib directory iif it doesn't yet exist).

Secondly, open <serverUrl>/application_server/server/webapps/ROOT/WEB-INF/web.xml and add the filter configuration shown below between the "</servlet-mapping>" and "</web-app>" tags.

Replace the value of the param-value with the generated Compact Privacy Policy string.

...
  <filter>
  	<filter-name>P3PHeaderFilter</filter-name>
  	<filter-class>com.servoy.extensions.server.filter.P3PHeaderFilter</filter-class>
  	<init-param>
  		<param-name>P3P-value</param-name>
  		<param-value>CP="CAO PSA OUR"</param-value>
  	</init-param>
  </filter>
  <filter-mapping>
  	<filter-name>P3PHeaderFilter</filter-name>
  	<url-pattern>/*</url-pattern>
  </filter-mapping>
...