Filter Rules
- Formulas are evaluated first, in order to have static values to manage.
- Filters will not necessarily overwrite past selections. There is no strict hierarchy.
- Each filter will be analyzed in sequence: "task -> user -> report -> object."
- The values of filter fields at different levels will be intersected.
- If the intersection gives an empty result, the filter chain will become invalid.
- There is no limit to how many task, report, object, or users filters you can apply in an app. However, only one object filter can be applied to a single image or table object in the NPrinting template editor.
- If the application of a filter results in an impossible selection, a specific error is returned: "Cannot apply filter {0} to current document data. Requested fields with evaluates are: {1}",
- 'Empty Set' Logging errors can be expected if the same dimension is used as a filter value twice in the "task -> user -> report -> object" sequence.
Filter intersection example: city=paris (user filter) and city=seatte (task filter)
Result: "Empty Set" Error logging
*Note that there is one specific flag that allows you to change these behaviors: "Override values". This flag, which is related to specific fields of a filter, allows you to clear the selections on a certain field on a certain level of the chain.
To view other examples of Filter intersections see the reference link below:
Reference: https://help.qlik.com/en-US/nprinting/April2019/Content/NPrinting/ReportsDevelopment/Static-dynamic-filters.htm#anchor-3Other Important Limitations to note:
- Tables that have calculated dimensions or null values can be used as levels in the template editor, however it is not supported to place any objects or additional 'nested' levels within them. Error indicating this usage limitation: "ERROR: Cannot expand cycle or level. Cycle expansion produces an empty filter"
- Qlik Sense On-Demand reports with selections applied on calculated dimensions will fail. This limitation is also specified in the NPrinting product release notes attached to this article.