Add possibility to check validity of a cell value, based on data validation rules

`$cell->hasValidValue()` returns true if the cell has a value which conform to the
rules defined in `$cell->getDataValidation()`.

Closes #257

Author: SailorMax

CHANGELOG.md

@@ -10,7 +10,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 
 - Support for chart fill color - @CrazyBite [#158](https://github.com/PHPOffice/PhpSpreadsheet/pull/158)
-- Support for read Hyperlink for xml - [@GreatHumorist](https://github.com/GreatHumorist) [#223](https://github.com/PHPOffice/PhpSpreadsheet/pull/223)
+- Support for read Hyperlink for xml - @GreatHumorist [#223](https://github.com/PHPOffice/PhpSpreadsheet/pull/223)
+- Support for cell value validation according to data validation rules - @SailorMax [#257](https://github.com/PHPOffice/PhpSpreadsheet/pull/257)
 
 ### Changed
 

src/PhpSpreadsheet/Cell/Cell.php

@@ -415,7 +415,19 @@ public function setDataValidation(DataValidation $pDataValidation = null)
     }
 
     /**
-     *    Does this cell contain a Hyperlink?
+     * Does this cell contain valid value?
+     *
+     * @return bool
+     */
+    public function hasValidValue()
+    {
+        $validator = new DataValidator();
+
+        return $validator->isValid($this);
+    }
+
+    /**
+     * Does this cell contain a Hyperlink?
      *
      * @throws Exception
      *

src/PhpSpreadsheet/Cell/DataValidator.php

@@ -0,0 +1,77 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheet\Cell;
+
+use PhpOffice\PhpSpreadsheet\Calculation\Calculation;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Exception;
+
+/**
+ * Validate a cell value according to its validation rules.
+ */
+class DataValidator
+{
+    /**
+     * Does this cell contain valid value?
+     *
+     * @param Cell $cell Cell to check the value
+     *
+     * @return bool
+     */
+    public function isValid(Cell $cell)
+    {
+        if (!$cell->hasDataValidation()) {
+            return true;
+        }
+
+        $cellValue = $cell->getValue();
+        $dataValidation = $cell->getDataValidation();
+
+        if (!$dataValidation->getAllowBlank() && ($cellValue === null || $cellValue === '')) {
+            return false;
+        }
+
+        // TODO: write check on all cases
+        switch ($dataValidation->getType()) {
+            case DataValidation::TYPE_LIST:
+                return $this->isValueInList($cell);
+        }
+
+        return false;
+    }
+
+    /**
+     * Does this cell contain valid value, based on list?
+     *
+     * @param Cell $cell Cell to check the value
+     *
+     * @return bool
+     */
+    private function isValueInList(Cell $cell)
+    {
+        $cellValue = $cell->getValue();
+        $dataValidation = $cell->getDataValidation();
+
+        $formula1 = $dataValidation->getFormula1();
+        if (!empty($formula1)) {
+            // inline values list
+            if ($formula1[0] === '"') {
+                return in_array(strtolower($cellValue), explode(',', strtolower(trim($formula1, '"'))), true);
+            } elseif (strpos($formula1, ':') > 0) {
+                // values list cells
+                $matchFormula = '=MATCH(' . $cell->getCoordinate() . ', ' . $formula1 . ', 0)';
+                $calculation = Calculation::getInstance($cell->getWorksheet()->getParent());
+
+                try {
+                    $result = $calculation->calculateFormula($matchFormula, $cell->getCoordinate(), $cell);
+
+                    return $result !== Functions::NA();
+                } catch (Exception $ex) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+}

tests/PhpSpreadsheetTests/Cell/DataValidatorTest.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Cell;
+
+use PhpOffice\PhpSpreadsheet\Cell\DataValidation;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PHPUnit_Framework_TestCase;
+
+class DataValidatorTest extends PHPUnit_Framework_TestCase
+{
+    public function testNoValidation()
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $testCell = $sheet->getCell('A1');
+
+        self::assertTrue($testCell->hasValidValue(), 'a cell without any validation data is always valid');
+    }
+
+    public function testUnsupportedType()
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $testCell = $sheet->getCell('A1');
+
+        $validation = $testCell->getDataValidation();
+        $validation->setType(DataValidation::TYPE_CUSTOM);
+        $validation->setAllowBlank(true);
+
+        self::assertFalse($testCell->hasValidValue(), 'cannot assert that value is valid when the validation type is not supported');
+    }
+
+    public function testList()
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $testCell = $sheet->getCell('A1');
+
+        $validation = $testCell->getDataValidation();
+        $validation->setType(DataValidation::TYPE_LIST);
+
+        // blank value
+        $testCell->setValue('');
+        $validation->setAllowBlank(true);
+        self::assertTrue($testCell->hasValidValue(), 'cell can be empty');
+        $validation->setAllowBlank(false);
+        self::assertFalse($testCell->hasValidValue(), 'cell can not be empty');
+
+        // inline list
+        $validation->setFormula1('"yes,no"');
+        $testCell->setValue('foo');
+        self::assertFalse($testCell->hasValidValue(), "cell value ('foo') is not allowed");
+        $testCell->setValue('yes');
+        self::assertTrue($testCell->hasValidValue(), "cell value ('yes') has to be allowed");
+
+        // list from cells
+        $sheet->getCell('B1')->setValue(5);
+        $sheet->getCell('B2')->setValue(6);
+        $sheet->getCell('B3')->setValue(7);
+        $testCell = $sheet->getCell('A1'); // redefine $testCell, because it has broken coordinates after using other cells
+        $validation->setFormula1('B1:B3');
+        $testCell->setValue('10');
+        self::assertFalse($testCell->hasValidValue(), "cell value ('10') is not allowed");
+        $testCell = $sheet->getCell('A1'); // redefine $testCell, because it has broken coordinates after using other cells
+        $testCell->setValue('5');
+        self::assertTrue($testCell->hasValidValue(), "cell value ('5') has to be allowed");
+
+        $testCell = $sheet->getCell('A1'); // redefine $testCell, because it has broken coordinates after using other cells
+        $validation->setFormula1('broken : cell : coordinates');
+
+        self::assertFalse($testCell->hasValidValue(), 'invalid formula should not throw exceptions');
+    }
+}