Create trellised visualizations based on marking

from Spotfire.Dxp.Application.Visuals import BarChart, VisualContent, VisualTypeIdentifiers, LabelOrientation, BarChartOrientation  

from Spotfire.Dxp.Application.Layout import LayoutDefinition

#script params
dataTable = Document.Data.Tables["Best predictors"]

#delete all barchart visuals
page = Document.ActivePageReference
for vis in page.Visuals:
if vis.TypeId == VisualTypeIdentifiers.BarChart:
page.Visuals.Remove(vis)

#The last visual left should be the treemap
tm = next(iter(page.Visuals))

#create a barchart template
bc = Application.Document.ActivePageReference.Visuals.AddNew[BarChart]()
bc.Data.DataTableReference = dataTable
bc.Title = "${DataTable.DisplayName}"
bc.Legend.Visible= False
bc.YAxis.Expression = "Sum([p-value])"
bc.XAxis.Expression = "<[Case Name]>"
bc.SortedBars=True
bc.Orientation = BarChartOrientation.Horizontal

#duplicate as many barcharts as selected sites from marking

siteNames = Document.Properties["markedSites"]
sites = [s.strip() for s in siteNames.split(',')]

#setup first barchart
firstSite = sites.pop()
bc.Title = firstSite
siteVisuals = [bc]

bc.Data.WhereClauseExpression = "[Site_No] = '"+firstSite+"'"

#create visuals
for site in sites:
vis = page.Visuals.AddDuplicate(bc.Visual)
vis.Title =site
bc = vis.As[BarChart]()
bc.Data.WhereClauseExpression = "[Site_No] = '"+site+"'"
siteVisuals.append(vis.As[BarChart]())

#arrange visuals
#tm is the existing treemap and will take 10% of the screen
ld = LayoutDefinition()
ld.BeginSideBySideSection()
ld.Add(tm, 10)

# Begin a stacked section for the second column at 70% of the screen
ld.BeginStackedSection(70)

i = 0
for bc in siteVisuals:
    if i % 3 == 0:
        if i > 0: ld.EndSection()
        ld.BeginSideBySideSection()
    ld.Add(bc.Visual)
    i += 1
ld.EndSection()
ld.EndSection()
ld.EndSection()

page.ApplyLayout(ld)

To trigger this script when marking changes, create a bypass data function. The script definition is simply an 'x' and so is the input and output. Make sure it runs automatically. The script parameters for the 'x' input is "UniqueConcatenate([Explore_YieldData - Explore_YieldData].[Site])" limited by the blue Marking. The output is a document property called "markedSites" that must be setup to trigger the above script when its value changes.