Download, Launch, and Param functions in canvas apps

Downloads or launches a webpage or an app with parameters.


The Download function downloads a file from the web to the local device. The user is prompted for a location to save the file. Download returns the location where the file was stored locally as a string.

The Launch function launches a webpage or an app. Optionally, this function can pass parameters to the app.

In Internet Explorer and Microsoft Edge, the Launch function opens a website or app only if its security settings are the same or higher than those of the app that contains the function. If, for example, you add the Launch function to an app that will run in the Trusted sites security zone, ensure that the website or app that you want the function to open is in the Trusted sites or Local intranet zone (not in Restricted sites). More information: Change security and privacy settings for Internet Explorer 11.

The Param function retrieves a parameter passed to the app when it was launched. If the named parameter wasn't passed, Param returns blank.


Download( Address )

  • Address - Required. The address of a web resource to download.

Launch( Address [, ParameterName1, ParameterValue1, ... ] )

  • Address - Required. The address of a webpage or the ID of an app to launch.
  • ParameterName(s) - Optional. Parameter name.
  • ParameterValue(s) - Optional. Corresponding parameter values to pass to the app or the webpage.

Param( ParameterName )

  • ParameterName - Required. The name of the parameter passed to the app.