External Content

With the External Content presentation object you can show content from some other website or web portal. The External Content presentation object uses html's iframe element to embed the websites. Using the External Content presentation object enables integrating multiple Web applications into a single UI.

Properties Tab

The following properties can be set on the Properties tab:

• Name: Name of the External Content presentation object.
• Description: Description for the External Content presentation object.
• External Content URL: The URL of the external page you want to embed in QPR UI. You can also use a relative path (e.g. "/examples/test.html"), if the page you want to embed is accessible by the same protocol, host, and port as QPR UI.

Accessing session context in the external webpage

Session context variables can be get and set from the external content webpage using following javascript functions:

• getSessionVariable(variableName) where following parameter is available:
  • variableName is the name of the read session context variable. This parameter is mandatory.
• setSessionVariable(variableName, variableValue, noNewHistoryEntry) where following parameters are available:
  • variableName is the name of the set session context variable. This parameter is mandatory.
  • variableValue is its value (the value must be string). This parameter is mandatory.
  • noNewHistoryEntry is a boolean value defining whether to create a new browser history entry of the context variable change. true defines that no new browser history entry is created. This means that when user click the Back button, it reverts both that context variable change and the latest history entry that existed before the context variable change. The parameter is optional and by default it's false.

Following code example shows how the context variables can be set and get through the window.parent object:

window.parent.setSessionVariable("variable1", "value1");
var variable1 = window.parent.getSessionVariable("variable1");

The external webpage must be referenced using the same server name and port as QPR UI, so that these javascript functions can be called. This is because of web browsers security features (same origin policy).

There is a test page available in the QPR UI where the functioning of these variables can be tested: /mobiledash/examples/test.html.

These functions interact only with the session context - not the external presentation object's effective context. To use presentation object's effective context in the external webpage, continue reading to the next chapter.

Passing effective context in the url

To access the external presentation object's effective context, you can pass context variable values in the iFrame url using the {#variableName} syntax. Example:

http(s)://SERVERNAME/ExternalPresentationObjects/ExternalPresentationObject1#variable1={#variable1}&variable2={#variable2}

If the variable references appear after the hash mark (#), the external web page is not refreshed when the context variables values change. In the external web page, url changes can be monitored through onhashchange javascript event of the window object. The following example registers a function that is called when the url changes:

window.onhashchange = function() {
  var iFrameUrl = window.location.href;
  var listOfParameters = iFrameUrl.substr(iFrameUrl.indexOf("#") + 1));
}

Web browser security considerations

Some websites prevent themselves to be embedded into other websites using iFrame. In those cases, the external content presentation object will be left blank (in Chrome and Firefox) or there may be an error message "This content cannot be displayed in a frame" (in Internet Explorer). The way to workaround the issue is to have X-Frame-Options HTTP response header changed in the embedded website (more information: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options). Template:MDBTutorialExternalContent