Refs #6078, allow default column limit to be specified through INI config.

config/global.ini.php

@@ -477,6 +477,12 @@ enable_update_communication = 1
 ; At present, this is very inefficient, so it is disabled by default.
 pivot_by_filter_enable_fetch_by_segment = 0
 
+; This controls the default maximum number of columns to display in a pivot table. Since a pivot table displays
+; a table's rows as columns, the number of columns can become very large, which will affect webpage layouts.
+; Set to -1 to specify no limit. Note: The pivotByColumnLimit query parameter can be used to override this default
+; on a per-request basis;
+pivot_by_filter_default_column_limit = 7
+
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core/DataTable/Filter/PivotByDimension.php

@@ -55,8 +55,6 @@ use Piwik\Plugin\Segment;
  */
 class PivotByDimension extends BaseFilter
 {
-    const DEFAULT_COLUMN_LIMIT = 7;
-
     /**
      * The pivot-by Dimension. The metadata in this class is used to determine if we can
      * pivot the report and used to fetch intersected tables.
@@ -157,7 +155,7 @@ class PivotByDimension extends BaseFilter
             $pivotColumn, $pivotByColumnLimit, $isFetchingBySegmentEnabled);
 
         $this->pivotColumn = $pivotColumn;
-        $this->pivotByColumnLimit = $pivotByColumnLimit ?: self::DEFAULT_COLUMN_LIMIT;
+        $this->pivotByColumnLimit = $pivotByColumnLimit ?: self::getDefaultColumnLimit();
         $this->isFetchingBySegmentEnabled = $isFetchingBySegmentEnabled;
 
         $namesToId = Metrics::getMappingFromIdToName();
@@ -456,4 +454,15 @@ class PivotByDimension extends BaseFilter
     {
         return Config::getInstance()->General['pivot_by_filter_enable_fetch_by_segment'];
     }
+
+    /**
+     * Returns the default maximum number of columns to allow in a pivot table from the INI config.
+     * Uses the **pivot_by_filter_default_column_limit** INI config option.
+     *
+     * @return int
+     */
+    public static function getDefaultColumnLimit()
+    {
+        return Config::getInstance()->General['pivot_by_filter_default_column_limit'];
+    }
 }
\ No newline at end of file