Added handling of blank data in charts.

.indent.pro

@@ -53,6 +53,7 @@
 -T lxw_chart_axis_label_position
 -T lxw_chart_axis_tick_mark
 -T lxw_chart_axis_tick_position
+-T lxw_chart_blank
 -T lxw_chart_fill
 -T lxw_chart_font
 -T lxw_chart_gridline

include/xlsxwriter/chart.h

@@ -514,6 +514,21 @@ typedef enum lxw_chart_axis_tick_mark {
     LXW_CHART_AXIS_TICK_MARK_CROSSING
 } lxw_chart_tick_mark;
 
+/**
+ * @brief Define how blank values are displayed in a chart.
+ */
+typedef enum lxw_chart_blank {
+
+    /** Show empty chart cells as gaps in the data. The default. */
+    LXW_CHART_BLANKS_AS_GAP,
+
+    /** Show empty chart cells as zeros. */
+    LXW_CHART_BLANKS_AS_ZERO,
+
+    /** Show empty chart cells as connected. Only for charts with lines. */
+    LXW_CHART_BLANKS_AS_CONNECTED
+} lxw_chart_blank;
+
 enum lxw_chart_position {
     LXW_CHART_AXIS_RIGHT,
     LXW_CHART_AXIS_LEFT,
@@ -884,6 +899,9 @@ typedef struct lxw_chart {
     uint8_t has_table_legend_keys;
     lxw_chart_font *table_font;
 
+    uint8_t show_blanks_as;
+    uint8_t show_hidden_data;
+
     STAILQ_ENTRY (lxw_chart) ordered_list_pointers;
     STAILQ_ENTRY (lxw_chart) list_pointers;
 
@@ -2545,6 +2563,42 @@ void chart_set_series_overlap(lxw_chart *chart, int8_t overlap);
  */
 void chart_set_series_gap(lxw_chart *chart, uint16_t gap);
 
+/**
+ * @brief Set the option for displaying blank data in a chart.
+ *
+ * @param chart    Pointer to a lxw_chart instance to be configured.
+ * @param option The display option. A #lxw_chart_blank option.
+ *
+ * The `%chart_show_blanks_as()` function controls how blank data is displayed
+ * in a chart:
+ *
+ * @code
+ *     chart_show_blanks_as(chart, LXW_CHART_BLANKS_AS_CONNECTED);
+ * @endcode
+ *
+ * The `option` parameter can have one of the following values:
+ *
+ * - #LXW_CHART_BLANKS_AS_GAP: Show empty chart cells as gaps in the data.
+ *   This is the default option for Excel charts.
+ * - #LXW_CHART_BLANKS_AS_ZERO: Show empty chart cells as zeros.
+ * - #LXW_CHART_BLANKS_AS_CONNECTED: Show empty chart cells as connected.
+ *   Only for charts with lines.
+ */
+void chart_show_blanks_as(lxw_chart *chart, uint8_t option);
+
+/**
+ * @brief Display data on charts from hidden rows or columns.
+ *
+ * @param chart Pointer to a lxw_chart instance to be configured.
+ *
+ * Display data that is in hidden rows or columns on the chart:
+ *
+ * @code
+ *     chart_show_hidden_data(chart);
+ * @endcode
+ */
+void chart_show_hidden_data(lxw_chart *chart);
+
 /**
  * @brief Set the Pie/Doughnut chart rotation.
  *

src/chart.c

@@ -2934,6 +2934,9 @@ _chart_write_plot_vis_only(lxw_chart *self)
     struct xml_attribute_list attributes;
     struct xml_attribute *attribute;
 
+    if (self->show_hidden_data)
+        return;
+
     LXW_INIT_ATTRIBUTES();
     LXW_PUSH_ATTRIBUTES_STR("val", "1");
 
@@ -3043,6 +3046,31 @@ _chart_write_gap_width(lxw_chart *self, uint16_t gap)
     LXW_FREE_ATTRIBUTES();
 }
 
+/*
+ * Write the <c:dispBlanksAs> element.
+ */
+STATIC void
+_chart_write_disp_blanks_as(lxw_chart *self)
+{
+    struct xml_attribute_list attributes;
+    struct xml_attribute *attribute;
+
+    if (self->show_blanks_as != LXW_CHART_BLANKS_AS_ZERO
+        && self->show_blanks_as != LXW_CHART_BLANKS_AS_CONNECTED)
+        return;
+
+    LXW_INIT_ATTRIBUTES();
+
+    if (self->show_blanks_as == LXW_CHART_BLANKS_AS_ZERO)
+        LXW_PUSH_ATTRIBUTES_STR("val", "zero");
+    else
+        LXW_PUSH_ATTRIBUTES_STR("val", "span");
+
+    lxw_xml_empty_tag(self->file, "c:dispBlanksAs", &attributes);
+
+    LXW_FREE_ATTRIBUTES();
+}
+
 /*
  * Write the <c:showHorzBorder> element.
  */
@@ -3841,6 +3869,9 @@ _chart_write_chart(lxw_chart *self)
     /* Write the c:plotVisOnly element. */
     _chart_write_plot_vis_only(self);
 
+    /* Write the c:dispBlanksAs element. */
+    _chart_write_disp_blanks_as(self);
+
     lxw_xml_end_tag(self->file, "c:chart");
 }
 
@@ -5129,6 +5160,24 @@ chart_set_series_overlap(lxw_chart *self, int8_t overlap)
                          overlap);
 }
 
+/*
+ * Set the option for displaying blank data in a chart.
+ */
+void
+chart_show_blanks_as(lxw_chart *self, uint8_t option)
+{
+    self->show_blanks_as = option;
+}
+
+/*
+ * Display data on charts from hidden rows or columns.
+ */
+void
+chart_show_hidden_data(lxw_chart *self)
+{
+    self->show_hidden_data = LXW_TRUE;
+}
+
 /*
  * Set the Bar/Column gap for all data series.
  */

test/functional/src/test_chart_blank01.c

@@ -0,0 +1,44 @@
+/*****************************************************************************
+ * Test cases for libxlsxwriter.
+ *
+ * Test to compare output against Excel files.
+ *
+ * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ *
+ */
+
+#include "xlsxwriter.h"
+
+int main() {
+
+    lxw_workbook  *workbook  = new_workbook("test_chart_blank01.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_LINE);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 45705856;
+    chart->axis_id_2 = 45843584;
+
+    uint8_t data[5][3] = {
+        {1, 2,  3},
+        {2, 4,  6},
+        {3, 6,  9},
+        {4, 8,  12},
+        {5, 10, 15}
+    };
+
+    int row, col;
+    for (row = 0; row < 5; row++)
+        for (col = 0; col < 3; col++)
+            worksheet_write_number(worksheet, row, col, data[row][col], NULL);
+
+    chart_add_series(chart, NULL, "=Sheet1!$A$1:$A$5");
+    chart_add_series(chart, NULL, "=Sheet1!$B$1:$B$5");
+    chart_add_series(chart, NULL, "=Sheet1!$C$1:$C$5");
+
+    chart_show_blanks_as(chart, LXW_CHART_BLANKS_AS_GAP);
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/src/test_chart_blank02.c

@@ -0,0 +1,44 @@
+/*****************************************************************************
+ * Test cases for libxlsxwriter.
+ *
+ * Test to compare output against Excel files.
+ *
+ * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ *
+ */
+
+#include "xlsxwriter.h"
+
+int main() {
+
+    lxw_workbook  *workbook  = new_workbook("test_chart_blank02.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_LINE);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 44253568;
+    chart->axis_id_2 = 44269952;
+
+    uint8_t data[5][3] = {
+        {1, 2,  3},
+        {2, 4,  6},
+        {3, 6,  9},
+        {4, 8,  12},
+        {5, 10, 15}
+    };
+
+    int row, col;
+    for (row = 0; row < 5; row++)
+        for (col = 0; col < 3; col++)
+            worksheet_write_number(worksheet, row, col, data[row][col], NULL);
+
+    chart_add_series(chart, NULL, "=Sheet1!$A$1:$A$5");
+    chart_add_series(chart, NULL, "=Sheet1!$B$1:$B$5");
+    chart_add_series(chart, NULL, "=Sheet1!$C$1:$C$5");
+
+    chart_show_blanks_as(chart, LXW_CHART_BLANKS_AS_ZERO);
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/src/test_chart_blank03.c

@@ -0,0 +1,44 @@
+/*****************************************************************************
+ * Test cases for libxlsxwriter.
+ *
+ * Test to compare output against Excel files.
+ *
+ * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ *
+ */
+
+#include "xlsxwriter.h"
+
+int main() {
+
+    lxw_workbook  *workbook  = new_workbook("test_chart_blank03.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_LINE);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 44253568;
+    chart->axis_id_2 = 44269952;
+
+    uint8_t data[5][3] = {
+        {1, 2,  3},
+        {2, 4,  6},
+        {3, 6,  9},
+        {4, 8,  12},
+        {5, 10, 15}
+    };
+
+    int row, col;
+    for (row = 0; row < 5; row++)
+        for (col = 0; col < 3; col++)
+            worksheet_write_number(worksheet, row, col, data[row][col], NULL);
+
+    chart_add_series(chart, NULL, "=Sheet1!$A$1:$A$5");
+    chart_add_series(chart, NULL, "=Sheet1!$B$1:$B$5");
+    chart_add_series(chart, NULL, "=Sheet1!$C$1:$C$5");
+
+    chart_show_blanks_as(chart, LXW_CHART_BLANKS_AS_CONNECTED);
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/src/test_chart_blank04.c

@@ -0,0 +1,53 @@
+/*****************************************************************************
+ * Test cases for libxlsxwriter.
+ *
+ * Test to compare output against Excel files.
+ *
+ * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ *
+ */
+
+#include "xlsxwriter.h"
+
+int main() {
+
+    lxw_workbook  *workbook  = new_workbook("test_chart_blank04.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_LINE);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 42268928;
+    chart->axis_id_2 = 42990208;
+
+    /* Leave some blanks in the default test data. */
+
+    worksheet_write_number(worksheet, 0, 0, 1,     NULL);
+    worksheet_write_number(worksheet, 1, 0, 2,     NULL);
+
+    worksheet_write_number(worksheet, 3, 0, 4,     NULL);
+    worksheet_write_number(worksheet, 4, 0, 5,     NULL);
+
+    worksheet_write_number(worksheet, 0, 1, 2,     NULL);
+    worksheet_write_number(worksheet, 1, 1, 4,     NULL);
+
+    worksheet_write_number(worksheet, 3, 1, 8,     NULL);
+    worksheet_write_number(worksheet, 4, 1, 10,    NULL);
+
+    worksheet_write_number(worksheet, 0, 2, 3,     NULL);
+    worksheet_write_number(worksheet, 1, 2, 6,     NULL);
+
+    worksheet_write_number(worksheet, 3, 2, 12,    NULL);
+    worksheet_write_number(worksheet, 4, 2, 15,    NULL);
+
+
+
+    chart_add_series(chart, NULL, "=Sheet1!$A$1:$A$5");
+    chart_add_series(chart, NULL, "=Sheet1!$B$1:$B$5");
+    chart_add_series(chart, NULL, "=Sheet1!$C$1:$C$5");
+
+    chart_show_blanks_as(chart, LXW_CHART_BLANKS_AS_CONNECTED);
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/src/test_chart_blank06.c

@@ -0,0 +1,44 @@
+/*****************************************************************************
+ * Test cases for libxlsxwriter.
+ *
+ * Test to compare output against Excel files.
+ *
+ * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ *
+ */
+
+#include "xlsxwriter.h"
+
+int main() {
+
+    lxw_workbook  *workbook  = new_workbook("test_chart_blank06.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_LINE);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 42270080;
+    chart->axis_id_2 = 42990208;
+
+    uint8_t data[5][3] = {
+        {1, 2,  3},
+        {2, 4,  6},
+        {3, 6,  9},
+        {4, 8,  12},
+        {5, 10, 15}
+    };
+
+    int row, col;
+    for (row = 0; row < 5; row++)
+        for (col = 0; col < 3; col++)
+            worksheet_write_number(worksheet, row, col, data[row][col], NULL);
+
+    chart_add_series(chart, NULL, "=Sheet1!$A$1:$A$5");
+    chart_add_series(chart, NULL, "=Sheet1!$B$1:$B$5");
+    chart_add_series(chart, NULL, "=Sheet1!$C$1:$C$5");
+
+    chart_show_hidden_data(chart);
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/test_chart_blank.py

@@ -0,0 +1,33 @@
+###############################################################################
+#
+# Tests for libxlsxwriter.
+#
+# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+#
+
+import base_test_class
+
+class TestCompareXLSXFiles(base_test_class.XLSXBaseTest):
+    """
+    Test file created with libxlsxwriter against a file created by Excel.
+
+    """
+
+    def test_chart_blank01(self):
+        self.run_exe_test('test_chart_blank01')
+
+    def test_chart_blank02(self):
+        self.run_exe_test('test_chart_blank02')
+
+    def test_chart_blank03(self):
+        self.run_exe_test('test_chart_blank03')
+
+    def test_chart_blank04(self):
+        self.run_exe_test('test_chart_blank04')
+
+    # Chartsheet.
+    # def test_chart_blank05(self):
+    #     self.run_exe_test('test_chart_blank05')
+
+    def test_chart_blank06(self):
+        self.run_exe_test('test_chart_blank06')