Sort WP_Query->posts Array of Objects conditionall

Question

I am having an array of Objects returned by WP_Query->posts

array
    0 =>
        object(WP_Post)
              public 'ID' 
              public 'post_title'
              public  'post_content'
   1 =>
        object(WP_Post)
              public 'ID' 
              public 'post_title'
              public  'post_content'
   2 =>
        object(WP_Post)
              public 'ID' 
              public 'post_title'
              public  'post_content'

  3 =>
        object(WP_Post)
              public 'ID' 
              public 'post_title'
              public  'post_content'
 4 =>
        object
              public 'Donor' 
              public 'date'
              public  'post_content'

And it goes on ...... I am trying to group this into first, second, third and fourth Quarter based on a date meta field ie; first quarter is the first three months (Jan, Feb ,March ), second quarter will be the next three and so on and give headings ,'First Quarter ,'Second Quarter ' etc:-

I achieved this by

<h3> First Quarter </h3>
<?php
     foreach($posts as $q1) {
       $donor_date = get_post_meta($q1->ID,'donor-date',true);
       $donor_month = date('m',strtotime($donor_date));

       if(!in_array($donor_month,array('01','02','03'),true)) continue;
?>
 <tr><td> <?php echo date('d/m/Y',strtotime($donor_date)); ?> </td></tr>
<?php endforeach; ?>

 <h3> Second Quarter </h3>
<?php
     foreach($posts as $q2) {
       $donor_date = get_post_meta($q2->ID,'donor-date',true);
       $donor_month = date('m',strtotime($donor_date));

       if(!in_array($donor_month,array('04','05','06'),true)) continue;
?>
 <tr><td> <?php echo date('d/m/Y',strtotime($donor_date)); ?> </td></tr>
<?php endforeach; ?>

and so on ...... the problem with this approach is that the headings ( First Quarter, Second Quarter ... ) will be there even if there is not data that meets the given condition . Is there a way to conditionally show and hide the headers too and a better method for sorting ( refactor) .......

Thanks in advance ........

Answer 1

You'll need to check the values in the array before starting any output.

I'd suggest doing this by saving the data to be displayed in an array instead of printing it immediately. Also, assuming $posts is the same in every foreach, you will only need to loop once.

Example with step-by-step instructions in the comments

<?php
/* declare an array to save the data */
$quarters = array();

foreach($posts as $q) {

   $donor_date = get_post_meta($q->ID,'donor-date',true);
   $donor_month = date('m',strtotime($donor_date));

   /* format the date once - best practice is not to repeat code */
   $formatteddate = date('d/m/Y',strtotime($donor_date));

   /* organise the dates by quarter, using the heading as the key for easy display */
   if(in_array($donor_month, array('01','02','03')))
       $quarters["First Quarter"][] = $formatteddate;

   else if(in_array($donor_month, array('04','05','06')))
       $quarters["Second Quarter"][] = $formatteddate;

   else if(in_array($donor_month, array('07','08','09')))
       $quarters["Third Quarter"][] = $formatteddate;

   else if(in_array($donor_month, array('10','11','12')))
       $quarters["Fourth Quarter"][] = $formatteddate;
}

 /* now go through your array and display the results */
 foreach ($quarters as $quartername => $quarter){
     /* $quarters won't have any entry for quarters with no dates, so technically this 'if' isn't needed,
       however I've added it in case it will be needed it for any other changes you make */
     if ($quarter){ ?>

         <h3><?php echo $quartername; ?></h3>
         <table>
         <?php  foreach ($quarter as $qdate ){ ?>
             <tr><td> <?php echo $qdate; ?> </td></tr>
         <?php  }  // end foreach($quarter...) ?>
         </table>
     <?php 
     } // end if 
} // end foreach($quarters...) 
?>

I'm not sure where your <table> element is created,because at the moment the <h3>s are added between <tr>s which is incorrect - however this mirrors the code you posted, so you should know how to work around that yourself!

Answer 2

Put the header inside the for loop and validate the month with if and else if statements to select which header display use one foreach statement

<?php
 foreach($posts as $q) {
   $donor_date = get_post_meta($q1->ID,'donor-date',true);
   $donor_month = date('m',strtotime($donor_date));
   if(in_array($donor_month,array('01','02','03'),true)) 
echo "<h3>First Quarter</h3>";
if(!in_array($donor_month,array('04','05','06'),true)
echo "<h3>Second Quarter</h3>";
?>
 <tr><td> <?php echo date('d/m/Y',strtotime($donor_date)); ?> </td></tr>
<?php endforeach; ?>