System Functions

System functions are used to give information about the environment and the app.

This article will cover the basic principles of working with these functions in the data load editor and visualisations, including:

  • The general function syntax
  • Working with system functions in the data load editor
  • Working with system functions in visualisations

For a complete, up-to-date list of system functions, please see the Qlik Sense help pages here.

The system function syntax

Not surprisingly, the general function syntax varies depending on the function. In this section, we will use an example function and decipher its syntax. This understanding will then help you read the syntax of other functions.

Example: ReloadTime

The ReloadTime() function returns the last time the app was reloaded.

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ReloadTime()

The rules for reading the function syntax are as follows:

  1. The function name itself is first and all the parameters you need to enter go between brackets: ().
  2. The various elements you will need to enter are separated by commas. This function doesn’t require any input parameters. Note that you still must include the brackets for the function to work.
  3. Anything between square brackets [] is an optional parameter. In this function, there are no optional parameters.

How to use system functions in the data load editor

Here are some important points on using system functions in the data load editor:

  • All of the functions can be used throughout the whole load script, not just within a LOAD or SELECT statement
  • The functions can be nested and combined with other types of functions
  • The functions can be particularly useful for returning information about the app to the user

How to use system functions in visualisations

Some system functions can be used in visualisations.

  • The functions can be nested and combined with other types of functions.
  • The functions are handy for displaying system information to users or restricting viewing access based on the user.

Here is an example of the ReloadTime() function used as a KPI to inform users when the app was last reloaded.