Paginated report architecture - is there any capability similar to user-defined global variables?

[tommy_g]

I am used to programming environments where you could define global variables or constants. In Report Builder, I'd like to set RGB color values and a few other similar items for use in expressions. The main report has six subreports. One of those includes a third level of subreporting.

I am thinking of two approaches, first defining and passing through hidden parameters. 

The second would be to define a dataset within each RDL component, reading values, similar to the old Config.sys file from ancient Windows versions. 

Neither are clean solutions, hoping from some enlightenment here....

[v-jingzhang · Accepted solution]

I think both of your approaches are good ideas and easy to maintain. In what ways do you hope to improve them?

[tommy_g]

I will probably have to agree with you either option will work.

As for how I would approve them, in many programming languages, including VB, you can define "manifest constants" which are available everywhere with no extra effort. Think "CRLF".

The report in question is needs to define a dozen client-specified colors (hex) and maybe another half-dozen other customizations. 

Under implementation option #1, I would have to add 18 values to the base RDL, then pass them to each subreport. Do-able, but lots of typing for the first six sub-reports, several of which have a third level.

Under implementation #2, I would need to define a dataset in each RDL. It offends my sense of style to re-open a dozen or more datasets which contain the exact same data. I'm not yet familiar with performance on loading multiple datasets in the report generator, we already have several dozen spread throughout. It's an odd report, not much data volume, but several dozen tablixes.

If implemented in "real" Power BI, I estimate 16 report tabs with an average of 4 visualizations each. This would be quite snappy with a clean Data Model since the storage engine would zip right through the simple DAX code. In the paginated report, I doubt data retrieval is quite that slick. I have not yet found anything related to performance in Paginated (or SSRS for that matter). Next step: ping the Cube Guys or other wizards.