What is Promise in NodeJs and example

NodeJs
Promises are a compelling alternative to callbacks when dealing with asynchronous code. Unfortunately, promises can be confusing and perhaps you’ve written them off. However, significant work has been done to bring out the essential beauty of promises in a way that is interoperable and verifiable.

You can make the function  that provide both a promise and callback interface. For example, let’s . how to deal with the real call back function to avoid call hell with Promise object.

var goal=false;
var youGol=new Promise(
function(resolve,reject ){

if(goal){
var myGoal={status:"Bikash is carrier Oriented"};
resolve(myGoal);
}else{
var reson=new Error('Bikash Nothing set his carrier');
reject(reson);
}

}
);

var goalstatu=function(){
youGol.then(function (answers){
console.log(answers);
}).catch(function (error){
console.log(error.message);
});

}



goalstatu();

How to download excel file using phpExcel core and joomla

its easy way to download php with mysql data into custom excel file using phpExcel library.

Please check below code step by step :

download PHPExcel library



public function downloadPHPexcel()
{

require_once (JPATH_SITE.'/phpexcel/Classes/PHPExcel.php');
require_once (JPATH_SITE.'/phpexcel/Classes/PHPExcel/IOFactory.php');
ini_set('memory_limit','2048M');    

$jinput = JFactory::getApplication()->input;
$buildername = $jinput->get('buildername', '', 'STRING');
$date1 = $jinput->get('date1', '', 'STRING');
$date2 = $jinput->get('date2', '', 'STRING');
$db = JFactory::getDbo();
$query  = $db->getQuery(true);    
$query ="SELECT *
FROM #__splms_videohit_track AS
courseTitle ASC";

$db->setQuery($query);
$isbtotalResult = $db->loadAssocList();

// Set title and meta data//
$objPHPExcel = new PHPExcel();
$objPHPExcel->getProperties()->setCreator("Creator")
            ->setLastModifiedBy("Modified")
            ->setTitle("Title")
            ->setSubject("Report")
            ->setDescription("ISB Report")
            ->setKeywords("report")
            ->setCategory("Report");
$rowNo = 1;    


$objPHPExcel->getActiveSheet()->setTitle(strtoupper($buildername.'_Members'));
// Set Header Column name//
$objPHPExcel->getDefaultStyle()->getFont()->setName('Calibiri')->setSize(11);
$objPHPExcel->getActiveSheet()->mergeCells('A1:F1');
$objPHPExcel->getActiveSheet()->getStyle('A1:F1')->getAlignment()->setHorizontal(PHPExcel_Style_Alignment::HORIZONTAL_CENTER);    
$objPHPExcel->getActiveSheet()->getStyle('A1:F1')->getFont()->setBold(true);    
$objPHPExcel->getActiveSheet()->setCellValue('A'.$rowNo, 'Bk® Confidential');
$rowNo=3;    
$objPHPExcel->getActiveSheet()->getStyle('A3:F3')->getFont()->setBold(true);
$objPHPExcel->getActiveSheet()->setCellValue('A'.$rowNo, 'Course Title');
$objPHPExcel->getActiveSheet()->setCellValue('B'.$rowNo, 'Registrant Name');
$objPHPExcel->getActiveSheet()->setCellValue('C'.$rowNo, 'Registrant Email');
$objPHPExcel->getActiveSheet()->setCellValue('D'.$rowNo, 'Register Date');

$objPHPExcel->getActiveSheet()->setAutoFilter('A3:D3');
//foreach loop for data get
$rowNo++;
foreach($isbtotalResult as $isbResultDetail){
   
   $objPHPExcel->getActiveSheet()->setCellValue('A'.$rowNo, $isbResultDetail['courseTitle']);
   $objPHPExcel->getActiveSheet()->setCellValue('B'.$rowNo, $isbResultDetail['name']);    
   $objPHPExcel->getActiveSheet()->setCellValue('C'.$rowNo, $isbResultDetail['email']);
   $objPHPExcel->getActiveSheet()->setCellValue('D'.$rowNo, $isbResultDetail['redate']);

   $rowNo++;
}
//for loop end    
$objPHPExcel->getActiveSheet()->getColumnDimension('A')->setWidth(30);
$objPHPExcel->getActiveSheet()->getColumnDimension('B')->setWidth(30);
for( $i='C'; $i<= 'D'; $i++ ){
   $objPHPExcel->getActiveSheet()->getColumnDimension($i)->setAutoSize(true);
}
$objPHPExcel->getActiveSheet()->getStyle('A'.$colHeder)->getAlignment()->setWrapText(true);
$objPHPExcel->getActiveSheet()->getStyle('B'.$colHeder)->getAlignment()->setWrapText(true);

$styleArray = array(
 'borders' => array(
     'allborders' => array(
 'style' => PHPExcel_Style_Border::BORDER_THIN
     )
 )
);
$rowNo = $objPHPExcel->getActiveSheet()->getHighestRow();
$objPHPExcel->getActiveSheet()->getStyle(
   'A1:' .
   $objPHPExcel->getActiveSheet()->getHighestColumn() .
   ($rowNo-1)
)->applyFromArray($styleArray);    


$reportFormat    = 'xlsx';
$year  = date('Y',strtotime($date1));
$Month = date('M',strtotime($date1));
$fileName         = 'My_Company_Engagement_Report_'.$Month.'_'.$year.'.'.$reportFormat;
$csvfileName = $fileName;
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
$objWriter->setPreCalculateFormulas(true);
$objWriter->setIncludeCharts(TRUE);
header("Content-Description: File Transfer");
header("Content-Type:   application/vnd.ms-excel; charset=utf-8");
header("Content-Disposition: attachment; filename=".$csvfileName);
header("Content-Transfer-Encoding: binary");
header("Expires: 0");
header("Cache-Control: must-revalidate");
header("Pragma: public");
$objWriter->save('php://output');
exit;
}

finally did then call the function : downloadPHPexcel();


ok, if you need to save the excel file into server Please refer below code

#################SAVE THE XLSX FILE INTO SERVER TOOT#######################

$fileName      = 'saveexcel.xlsx';
$objWriter      = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
$objWriter->setPreCalculateFormulas(true);
$objWriter->setIncludeCharts(TRUE);
$DownLoadPath = ABS_PATH.'download/'.$csvfileName;
$objWriter->save($DownLoadPath);
#################SAVE THE XLSX FILE INTO SERVER TOOT#######################