If you are using the Qlik Sense standard client there is a Selection toolbar displayed at the top of the page. It has lots of useful functionality, including search support, so in many cases you would want to use this in a mashup, which is perfectly possible.
But sometimes the selection toolbar does not fit in your web page or you want something more compact. In that case you can listen to selection changes yourself and visualize the selection state.
The way to get the selection state is the getList method. An example:
The reply will contain a qSelectionObject with:
- qBackCount and qForwardCount, the number of steps forward and backward that is possible
- a qSelections array, with on entry for every field that is selected
- the array entries will contain qField – the field name, qTotal – total number of different values in the field and qSelectedCount – the number of selected values
Using this you can make your own visualization of selection state, or perhaps hide and show visualizations based on selection states.