The application library

As previously mentioned, the Assets panel can show object types and fields. However, it has a third tab for predefined library entities. If you click on this tab, you will see the application library:

The library contains entities that have been predefined and that can simplify the Qlik Sense usage for a business user. Dimensions, measures, or entire visualizations can be stored in the library.

You do not need to use the library—nothing has to be predefined for Qlik Sense to work. However, if you want to reuse formulas or you have a situation where your task is to deliver an app to a business user, it is a good idea to use the library.

Which fields should be exposed?

Often, you have many fields in an app, of which maybe only a few should be exposed as dimensions. Then, you should use the library to define the fields that are appropriate as dimensions, and name them in a way that they can be easily understood.

A dimension can also be a group of fields that is exposed as a drill-down group. It can also be a formula using an Aggr() function that defines an array of values. In both these cases, it is a good idea to define the dimension in the library.

Defining KPIs

Measures are formulas that define KPIs and other numbers relevant for the analysis. These are often used in multiple places in an app, so it is convenient to store the definition in one place only. Then, should you want to change the definition, you need to do it in the library only. Also, this is a way to ensure that there is only one version of the truth.

Creating library entries

Library entries can be created in several different ways. The most obvious way is to enter the library and click on the Create new button.

An alternative way is to do it from Data model viewer. Here, you can mark a field and click on the Preview button (in the bottom-left corner of the screen). You have the option of adding the field as dimension or measure.

Whichever way you choose to use when you create your dimension, you will see the following dialog where you define your dimensions:

The Create new dimension dialog

When you create a measure, you will see the following dialog. Make sure that you have an aggregation function, for example, Sum(), Count(), or Min(), wrapping the field reference:

The Create new measure dialog

Visualizations can only be entered into the library by the use of drag and drop, so you need to have created the visualization on the sheet first.