Add option to set exportFormat from Column builder.

README.md

@@ -86,6 +86,56 @@ You can set the export type by setting the property to `csv` or `xlsx`. Default
 <livewire:export-button :table-id="$dataTable->getTableId()" type="csv" />
 ```
 
+## Formatting Columns
+
+You can format column by setting it via Column definition on you DataTable service class.
+
+```phpt
+Column::make('mobile')->exportFormat('00000000000'),
+```
+
+The format above will treat mobile numbers with leading zeroes.
+
+## Date Fields Formatting
+
+The package will auto-detect date fields when used with a valid format.
+
+```phpt
+Column::make('report_date')->exportFormat('mm/dd/yyyy'),
+Column::make('created_at'),
+Column::make('updated_at')->exportFormat(NumberFormat::FORMAT_DATE_DATETIME),
+```
+
+## Valid Date Formats
+
+Valid date formats can be adjust on `datatables-export.php` config file.
+
+```phpt
+    'date_formats' => [
+        'mm/dd/yyyy',
+        NumberFormat::FORMAT_DATE_DATETIME,
+        NumberFormat::FORMAT_DATE_YYYYMMDD,
+        NumberFormat::FORMAT_DATE_XLSX22,
+        NumberFormat::FORMAT_DATE_DDMMYYYY,
+        NumberFormat::FORMAT_DATE_DMMINUS,
+        NumberFormat::FORMAT_DATE_DMYMINUS,
+        NumberFormat::FORMAT_DATE_DMYSLASH,
+        NumberFormat::FORMAT_DATE_MYMINUS,
+        NumberFormat::FORMAT_DATE_TIME1,
+        NumberFormat::FORMAT_DATE_TIME2,
+        NumberFormat::FORMAT_DATE_TIME3,
+        NumberFormat::FORMAT_DATE_TIME4,
+        NumberFormat::FORMAT_DATE_TIME5,
+        NumberFormat::FORMAT_DATE_TIME6,
+        NumberFormat::FORMAT_DATE_TIME7,
+        NumberFormat::FORMAT_DATE_XLSX14,
+        NumberFormat::FORMAT_DATE_XLSX15,
+        NumberFormat::FORMAT_DATE_XLSX16,
+        NumberFormat::FORMAT_DATE_XLSX17,
+        NumberFormat::FORMAT_DATE_YYYYMMDD2,
+        NumberFormat::FORMAT_DATE_YYYYMMDDSLASH,
+    ]
+```
 
 ## Contributing
 

src/Exports/DataTableQueuedExport.php

@@ -2,20 +2,31 @@
 
 namespace Yajra\DataTables\Exports;
 
+use Carbon\Carbon;
 use Illuminate\Support\Collection;
 use Maatwebsite\Excel\Concerns\Exportable;
 use Maatwebsite\Excel\Concerns\FromQuery;
+use Maatwebsite\Excel\Concerns\WithColumnFormatting;
 use Maatwebsite\Excel\Concerns\WithHeadings;
 use Maatwebsite\Excel\Concerns\WithMapping;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 use Yajra\DataTables\Html\Column;
 
-class DataTableQueuedExport implements FromQuery, WithMapping, WithHeadings
+class DataTableQueuedExport implements FromQuery, WithMapping, WithHeadings, WithColumnFormatting
 {
     use Exportable;
 
     protected $query;
     protected $columns;
 
+    /**
+     * Index of fields with date instance.
+     *
+     * @var array
+     */
+    protected $dates = [];
+
     public function __construct($query, Collection $columns)
     {
         $this->query = $query;
@@ -30,8 +41,24 @@ public function query()
     public function map($row): array
     {
         return $this->columns
-            ->map(function (Column $column) use ($row) {
-                return $row[$column['data']];
+            ->map(function (Column $column, $index) use ($row) {
+                $property = $column['data'];
+
+                if ($row[$property] instanceof \DateTime) {
+                    $this->dates[] = $index;
+
+                    return Date::dateTimeToExcel($row[$property]);
+                }
+
+                if ($this->wantsDateFormat($column)) {
+                    $this->dates[] = $index;
+
+                    $dateValue = $row[$property];
+
+                    return $dateValue ? Date::dateTimeToExcel(Carbon::parse($dateValue)) : '';
+                }
+
+                return $row[$property];
             })
             ->toArray();
     }
@@ -40,4 +67,45 @@ public function headings(): array
     {
         return $this->columns->pluck('title')->toArray();
     }
+
+    public function columnFormats(): array
+    {
+        $formats = [];
+
+        $this->columns
+            ->each(function (Column $column, $index) use (&$formats) {
+                if (in_array($index, $this->dates) || $this->wantsDateFormat($column)) {
+                    return $formats[$this->num2alpha($index - 1)] = $column['exportFormat'] ?? NumberFormat::FORMAT_DATE_YYYYMMDD;
+                }
+
+                if (isset($column['exportFormat'])) {
+                    return $formats[$this->num2alpha($index - 1)] = $column['exportFormat'];
+                }
+            })
+            ->toArray();
+
+        return $formats;
+    }
+
+    protected function num2alpha($n)
+    {
+        for ($r = ""; $n >= 0; $n = intval($n / 26) - 1) {
+            $r = chr($n % 26 + 0x41) . $r;
+        }
+
+        return $r;
+    }
+
+    /**
+     * @param  \Yajra\DataTables\Html\Column  $column
+     * @return bool
+     */
+    protected function wantsDateFormat(Column $column): bool
+    {
+        if (!isset($column['exportFormat'])) {
+            return false;
+        }
+
+        return in_array($column['exportFormat'], config('datatables-export.date_formats', []));
+    }
 }

src/config/datatables-export.php

@@ -1,3 +1,34 @@
 <?php
 
-return [];
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+
+return [
+
+    /**
+     * List of valid date formats to be used for auto-detection.
+     */
+    'date_formats' => [
+        'mm/dd/yyyy',
+        NumberFormat::FORMAT_DATE_DATETIME,
+        NumberFormat::FORMAT_DATE_YYYYMMDD,
+        NumberFormat::FORMAT_DATE_XLSX22,
+        NumberFormat::FORMAT_DATE_DDMMYYYY,
+        NumberFormat::FORMAT_DATE_DMMINUS,
+        NumberFormat::FORMAT_DATE_DMYMINUS,
+        NumberFormat::FORMAT_DATE_DMYSLASH,
+        NumberFormat::FORMAT_DATE_MYMINUS,
+        NumberFormat::FORMAT_DATE_TIME1,
+        NumberFormat::FORMAT_DATE_TIME2,
+        NumberFormat::FORMAT_DATE_TIME3,
+        NumberFormat::FORMAT_DATE_TIME4,
+        NumberFormat::FORMAT_DATE_TIME5,
+        NumberFormat::FORMAT_DATE_TIME6,
+        NumberFormat::FORMAT_DATE_TIME7,
+        NumberFormat::FORMAT_DATE_XLSX14,
+        NumberFormat::FORMAT_DATE_XLSX15,
+        NumberFormat::FORMAT_DATE_XLSX16,
+        NumberFormat::FORMAT_DATE_XLSX17,
+        NumberFormat::FORMAT_DATE_YYYYMMDD2,
+        NumberFormat::FORMAT_DATE_YYYYMMDDSLASH,
+    ]
+];