pruning empty rows before calculating row sizes.

lib/open_project/pdf_export/taskboard_card/card_element.rb

@@ -6,15 +6,15 @@ module OpenProject::PdfExport::TaskboardCard
       @rows_config = rows_config
       @work_package = work_package
       @row_elements = []
+      @rows = @rows_config["rows"]
+
+      # Simpler to remove empty rows before calculating the row sizes
+      RowElement.prune_empty_rows(@rows, work_package)
 
-      # Initialize row elements
-      # TODO: It would be useful at this point to remove empty rows which do not need to be rendered if empty.
-      # This would fit better at column drawing time but by then it's too late because the heights have already
-      # been assigned.
       heights = assign_row_heights
       current_y_offset = 0
 
-      @rows_config["rows"].each_with_index do |(key, value), i|
+      @rows.each_with_index do |(key, value), i|
         current_y_offset += heights[i - 1] if i > 0
         row_orientation = {
           y_offset: @orientation[:height] - current_y_offset,
@@ -30,7 +30,7 @@ module OpenProject::PdfExport::TaskboardCard
     def assign_row_heights
       # Assign initial heights
       available = @orientation[:height]
-      c = @rows_config["rows"].count
+      c = @rows.count
       assigned_heights = Array.new(c){available/c}
 
       min_heights = min_row_heights(c)

lib/open_project/pdf_export/taskboard_card/row_element.rb

@@ -10,7 +10,7 @@ module OpenProject::PdfExport::TaskboardCard
       # Initialise column elements
       x_offset = 0
 
-      columns_config.each_with_index do |key, value|
+      columns_config.each do |key, value|
         width = col_width(value)
         column_orientation = @orientation.clone
         column_orientation[:x_offset] = x_offset
@@ -36,5 +36,20 @@ module OpenProject::PdfExport::TaskboardCard
         c.draw
       end
     end
+
+    def self.prune_empty_rows(rows, wp)
+      rows.each_with_index do |(rk, rv), i|
+        ck, cv = rv["columns"].first
+        if is_empty_column(ck, cv, wp)
+          rows.delete(rk)
+        end
+      end
+    end
+
+    def self.is_empty_column(property_name, column, wp)
+      value = wp.send(property_name) if wp.respond_to?(property_name) else ""
+      value = value.to_s if !value.is_a?(String)
+      !column["render_if_empty"] && value.empty?
+    end
   end
 end