PHPOffice · Progi1984 · Jul 27, 2021 · Jul 26, 2021
diff --git a/docs/changes/1.0.0.md b/docs/changes/1.0.0.md
@@ -40,6 +40,9 @@
 - Support for rotation for axis label - @Progi1986 GH-410
   - ODPresentation Writer
   - PowerPoint2007 Writer
+- Support for managing missing values in Chart - @TonisOrmisson GH-581 & @Progi1986 GH-659
+  - ODPresentation Writer
+  - PowerPoint2007 Writer
 
 ## Project Management
 - Migrated from Travis CI to Github Actions - @Progi1984 GH-635

diff --git a/docs/images/libreoffice_chart_displayblankas.png b/docs/images/libreoffice_chart_displayblankas.png
diff --git a/docs/usage/presentation.md b/docs/usage/presentation.md
@@ -138,7 +138,7 @@ $state = $presentation->isMarkedAsFinal();
 
 You can define the type of slideshow you can with the method `setSlideshowType`.
 
-![Slideshow type](/PHPPresentation/images/presentation_slideshow_type.png)
+![Slideshow type](/images/presentation_slideshow_type.png)
 
 Differents types are available:
 

diff --git a/docs/usage/shapes/chart.md b/docs/usage/shapes/chart.md
@@ -8,6 +8,31 @@ To create a chart, use `createChartShape` method of Slide.
 $chartShape = $slide->createChartShape();
 ```
 
+## Customization
+
+### Manage how blank values are displayed
+
+You can define how blank values are displayed with the method `setDisplayBlankAs`.
+
+![Slideshow type](/images/libreoffice_chart_displayblankas.png)
+
+Differents types are available:
+
+* `Chart::BLANKAS_GAP` for **Leave a gap**
+* `Chart::BLANKAS_ZERO` for **Assume zero** (default)
+* `Chart::BLANKAS_SPAN` for **Continue line**
+
+``` php
+<?php
+
+use PhpOffice\PhpPresentation\Shape\Chart;
+
+// Set the behavior
+$chart->setDisplayBlankAs(Chart::BLANKAS_GAP);
+// Get the behavior
+echo $chart->getDisplayBlankAs();
+```
+
 ## Parts
 
 ### Axis

diff --git a/samples/Sample_05_Chart_Line.php b/samples/Sample_05_Chart_Line.php
@@ -3,11 +3,15 @@
 include_once 'Sample_Header.php';
 
 use PhpOffice\PhpPresentation\PhpPresentation;
+use PhpOffice\PhpPresentation\Shape\Chart;
+use PhpOffice\PhpPresentation\Shape\Chart\Gridlines;
+use PhpOffice\PhpPresentation\Shape\Chart\Marker;
 use PhpOffice\PhpPresentation\Shape\Chart\Series;
 use PhpOffice\PhpPresentation\Shape\Chart\Type\Line;
 use PhpOffice\PhpPresentation\Style\Border;
 use PhpOffice\PhpPresentation\Style\Color;
 use PhpOffice\PhpPresentation\Style\Fill;
+use PhpOffice\PhpPresentation\Style\Outline;
 use PhpOffice\PhpPresentation\Style\Shadow;
 
 // Create new PHPPresentation object
@@ -73,7 +77,7 @@
 $currentSlide = createTemplatedSlide($objPHPPresentation);
 
 // Create a line chart (that should be inserted in a shape)
-$oOutline = new \PhpOffice\PhpPresentation\Style\Outline();
+$oOutline = new Outline();
 $oOutline->getFill()->setFillType(Fill::FILL_SOLID);
 $oOutline->getFill()->setStartColor(new Color(Color::COLOR_YELLOW));
 $oOutline->setWidth(2);
@@ -82,7 +86,7 @@
 $lineChart1 = clone $lineChart;
 $series1 = $lineChart1->getSeries();
 $series1[0]->setOutline($oOutline);
-$series1[0]->getMarker()->setSymbol(\PhpOffice\PhpPresentation\Shape\Chart\Marker::SYMBOL_DIAMOND);
+$series1[0]->getMarker()->setSymbol(Marker::SYMBOL_DIAMOND);
 $series1[0]->getMarker()->setSize(7);
 $lineChart1->setSeries($series1);
 
@@ -106,7 +110,7 @@
 $lineChart2 = clone $lineChart;
 $series2 = $lineChart2->getSeries();
 $series2[0]->getFont()->setSize(25);
-$series2[0]->getMarker()->setSymbol(\PhpOffice\PhpPresentation\Shape\Chart\Marker::SYMBOL_TRIANGLE);
+$series2[0]->getMarker()->setSymbol(Marker::SYMBOL_TRIANGLE);
 $series2[0]->getMarker()->setSize(10);
 $lineChart2->setSeries($series2);
 
@@ -129,11 +133,11 @@
 echo date('H:i:s') . ' Create a line chart (that should be inserted in a chart shape)' . EOL;
 $lineChart3 = clone $lineChart;
 
-$oGridLines1 = new \PhpOffice\PhpPresentation\Shape\Chart\Gridlines();
+$oGridLines1 = new Gridlines();
 $oGridLines1->getOutline()->setWidth(10);
 $oGridLines1->getOutline()->getFill()->setFillType(Fill::FILL_SOLID)->setStartColor(new Color(Color::COLOR_BLUE));
 
-$oGridLines2 = new \PhpOffice\PhpPresentation\Shape\Chart\Gridlines();
+$oGridLines2 = new Gridlines();
 $oGridLines2->getOutline()->setWidth(1);
 $oGridLines2->getOutline()->getFill()->setFillType(Fill::FILL_SOLID)->setStartColor(new Color(Color::COLOR_DARKGREEN));
 
@@ -156,12 +160,12 @@
 echo date('H:i:s') . ' Create a line chart (that should be inserted in a chart shape)' . EOL;
 $lineChart4 = clone $lineChart;
 
-$oOutlineAxisX = new \PhpOffice\PhpPresentation\Style\Outline();
+$oOutlineAxisX = new Outline();
 $oOutlineAxisX->setWidth(2);
 $oOutlineAxisX->getFill()->setFillType(Fill::FILL_SOLID);
 $oOutlineAxisX->getFill()->getStartColor()->setRGB('012345');
 
-$oOutlineAxisY = new \PhpOffice\PhpPresentation\Style\Outline();
+$oOutlineAxisY = new Outline();
 $oOutlineAxisY->setWidth(5);
 $oOutlineAxisY->getFill()->setFillType(Fill::FILL_SOLID);
 $oOutlineAxisY->getFill()->getStartColor()->setRGB('ABCDEF');
@@ -190,6 +194,26 @@
 $shape5->getPlotArea()->getAxisY()->setMinBounds(5);
 $shape5->getPlotArea()->getAxisY()->setMaxBounds(20);
 $currentSlide->addShape($shape5);
+
+// Create templated slide
+echo EOL . date('H:i:s') . ' Create templated slide #6' . EOL;
+$currentSlide = createTemplatedSlide($objPHPPresentation);
+
+// Create a shape (chart)
+echo date('H:i:s') . ' Create a shape (chart6)' . EOL;
+echo date('H:i:s') . ' Feature : DisplayBlankAs' . EOL;
+$shape6 = clone $shape;
+$lineChart6 = clone $lineChart;
+$series6 = clone $series;
+$seriesData6 = $seriesData;
+$seriesData6['Thursday'] = null;
+
+$series6->setValues($seriesData6);
+$lineChart6->setSeries([$series6]);
+$shape6->getPlotArea()->setType($lineChart6);
+$shape6->setDisplayBlankAs(Chart::BLANKAS_GAP);
+$currentSlide->addShape($shape6);
+
 // Save file
 echo EOL . write($objPHPPresentation, basename(__FILE__, '.php'), $writers);
 

diff --git a/src/PhpPresentation/Shape/Chart.php b/src/PhpPresentation/Shape/Chart.php
@@ -29,6 +29,10 @@
  */
 class Chart extends AbstractGraphic implements ComparableInterface
 {
+    public const BLANKAS_GAP = 'gap';
+    public const BLANKAS_ZERO = 'zero';
+    public const BLANKAS_SPAN = 'span';
+
     /**
      * Title.
      *
@@ -64,6 +68,13 @@ class Chart extends AbstractGraphic implements ComparableInterface
      */
     private $includeSpreadsheet = false;
 
+    /**
+     * How to display blank (missing) values? Not set by default.
+     *
+     * @var string
+     */
+    private $displayBlankAs = self::BLANKAS_ZERO;
+
     /**
      * Create a new Chart.
      */
@@ -89,6 +100,16 @@ public function __clone()
         $this->view3D = clone $this->view3D;
     }
 
+    /**
+     * How missing/blank values are displayed on chart (dispBlanksAs property)
+     *
+     * @return string
+     */
+    public function getDisplayBlankAs(): string
+    {
+        return $this->displayBlankAs;
+    }
+
     /**
      * Get Title.
      *
@@ -139,6 +160,22 @@ public function hasIncludedSpreadsheet(): bool
         return $this->includeSpreadsheet;
     }
 
+    /**
+     * Define a way to display missing/blank values (dispBlanksAs property)
+     *
+     * @param string $value
+     *
+     * @return self
+     */
+    public function setDisplayBlankAs(string $value): self
+    {
+        if (in_array($value, [self::BLANKAS_GAP, self::BLANKAS_SPAN, self::BLANKAS_ZERO])) {
+            $this->displayBlankAs = $value;
+        }
+
+        return $this;
+    }
+
     /**
      * Is the spreadsheet included for editing data ?
      *

diff --git a/src/PhpPresentation/Shape/Chart/Series.php b/src/PhpPresentation/Shape/Chart/Series.php
@@ -132,7 +132,7 @@ class Series implements ComparableInterface
     /**
      * Values (key/value).
      *
-     * @var array<string, string>
+     * @var array<string, string|null>
      */
     private $values = [];
 
@@ -144,17 +144,19 @@ class Series implements ComparableInterface
     private $hashIndex;
 
     /**
-     * @param array<string, string> $values
+     * @param string $title
+     * @param array<string, string|null> $values
      */
     public function __construct(string $title = 'Series Title', array $values = [])
     {
         $this->fill = new Fill();
         $this->font = new Font();
         $this->font->setName('Calibri');
         $this->font->setSize(9);
+        $this->marker = new Marker();
+
         $this->title = $title;
         $this->values = $values;
-        $this->marker = new Marker();
     }
 
     /**
@@ -239,7 +241,7 @@ public function getDataPointFills(): array
     /**
      * Get Values.
      *
-     * @return array<string, string>
+     * @return array<string, string|null>
      */
     public function getValues(): array
     {
@@ -249,7 +251,7 @@ public function getValues(): array
     /**
      * Set Values.
      *
-     * @param array<string, string> $values
+     * @param array<string, string|null> $values
      */
     public function setValues(array $values = []): self
     {
@@ -260,8 +262,13 @@ public function setValues(array $values = []): self
 
     /**
      * Add Value.
+     *
+     * @param string $key
+     * @param string|null $value
+     *
+     * @return self
      */
-    public function addValue(string $key, string $value): self
+    public function addValue(string $key, ?string $value): self
     {
         $this->values[$key] = $value;
 

diff --git a/src/PhpPresentation/Writer/ODPresentation/ObjectsChart.php b/src/PhpPresentation/Writer/ODPresentation/ObjectsChart.php
@@ -544,6 +544,17 @@ private function writePlotAreaStyle(Chart $chart): void
             $this->xmlContent->writeAttribute('chart:three-dimensional', 'true');
             $this->xmlContent->writeAttribute('chart:right-angled-axes', 'true');
         }
+        switch ($chart->getDisplayBlankAs()) {
+            case Chart::BLANKAS_ZERO:
+                $this->xmlContent->writeAttribute('chart:treat-empty-cells', 'use-zero');
+                break;
+            case Chart::BLANKAS_GAP:
+                $this->xmlContent->writeAttribute('chart:treat-empty-cells', 'leave-gap');
+                break;
+            case Chart::BLANKAS_SPAN:
+                $this->xmlContent->writeAttribute('chart:treat-empty-cells', 'ignore');
+                break;
+        }
         if ($chartType instanceof AbstractTypeBar) {
             $chartVertical = 'false';
             if (AbstractTypeBar::DIRECTION_HORIZONTAL == $chartType->getBarDirection()) {
@@ -809,40 +820,6 @@ private function writeTable(): void
         // > table:table-header-columns
         $this->xmlContent->endElement();
 
-        // table:table-rows
-        $this->xmlContent->startElement('table:table-rows');
-        if (empty($this->arrayData)) {
-            $this->xmlContent->startElement('table:table-row');
-            $this->xmlContent->startElement('table:table-cell');
-            $this->xmlContent->endElement();
-            $this->xmlContent->endElement();
-        } else {
-            foreach ($this->arrayData as $row) {
-                // table:table-row
-                $this->xmlContent->startElement('table:table-row');
-                foreach ($row as $cell) {
-                    // table:table-cell
-                    $this->xmlContent->startElement('table:table-cell');
-
-                    $cellNumeric = is_numeric($cell);
-                    $this->xmlContent->writeAttributeIf(!$cellNumeric, 'office:value-type', 'string');
-                    $this->xmlContent->writeAttributeIf($cellNumeric, 'office:value-type', 'float');
-                    $this->xmlContent->writeAttributeIf($cellNumeric, 'office:value', $cell);
-                    // text:p
-                    $this->xmlContent->startElement('text:p');
-                    $this->xmlContent->text($cell);
-                    // > text:p
-                    $this->xmlContent->endElement();
-                    // > table:table-cell
-                    $this->xmlContent->endElement();
-                }
-                // > table:table-row
-                $this->xmlContent->endElement();
-            }
-        }
-        // > table:table-rows
-        $this->xmlContent->endElement();
-
         // table:table-header-rows
         $this->xmlContent->startElement('table:table-header-rows');
         // table:table-row
@@ -874,6 +851,39 @@ private function writeTable(): void
         // > table:table-header-rows
         $this->xmlContent->endElement();
 
+        // table:table-rows
+        $this->xmlContent->startElement('table:table-rows');
+        if (empty($this->arrayData)) {
+            $this->xmlContent->startElement('table:table-row');
+            $this->xmlContent->startElement('table:table-cell');
+            $this->xmlContent->endElement();
+            $this->xmlContent->endElement();
+        } else {
+            foreach ($this->arrayData as $row) {
+                // table:table-row
+                $this->xmlContent->startElement('table:table-row');
+                foreach ($row as $cell) {
+                    // table:table-cell
+                    $this->xmlContent->startElement('table:table-cell');
+
+                    $cellValueTypeFloat = is_null($cell) ? true : is_numeric($cell);
+                    $this->xmlContent->writeAttributeIf(!$cellValueTypeFloat, 'office:value-type', 'string');
+                    $this->xmlContent->writeAttributeIf($cellValueTypeFloat, 'office:value-type', 'float');
+                    $this->xmlContent->writeAttributeIf($cellValueTypeFloat, 'office:value', is_null($cell) ? 'NaN' : $cell);
+                    // text:p
+                    $this->xmlContent->startElement('text:p');
+                    $this->xmlContent->text(is_null($cell) ? 'NaN' : $cell);
+                    $this->xmlContent->endElement();
+                    // > table:table-cell
+                    $this->xmlContent->endElement();
+                }
+                // > table:table-row
+                $this->xmlContent->endElement();
+            }
+        }
+        // > table:table-rows
+        $this->xmlContent->endElement();
+
         // > table:table
         $this->xmlContent->endElement();
     }

diff --git a/src/PhpPresentation/Writer/PowerPoint2007/PptCharts.php b/src/PhpPresentation/Writer/PowerPoint2007/PptCharts.php
@@ -146,6 +146,11 @@ public function writeChart(Chart $chart): string
         $objWriter->writeAttribute('val', '1');
         $objWriter->endElement();
 
+        // c:dispBlanksAs
+        $objWriter->startElement('c:dispBlanksAs');
+        $objWriter->writeAttribute('val', $chart->getDisplayBlankAs());
+        $objWriter->endElement();
+
         $objWriter->endElement();
 
         // c:spPr