Answered Checkbox confusion!

$i = 0;
$groupArray = array();
foreach($group as $selected) {
    $condition = ($i) ? 'OR:' : '';
    $groupArray[$condition.'pre:='] = $selected;
    $i++;
    $modx->setPlaceholder($selected . '_checked', $checked);
}
$j = 0;
$projArray = array();
foreach($proj as $select) {
    $cond = ($j) ? 'OR:' : '';
    $projArray[$cond.'proj:LIKE'] = $select.'.'.'%';
    $j++;
    $modx->setPlaceholder($select . '_checked', $checked);
}
if ((!empty($projArray)) && (!empty($groupArray))) {
    $c->where(array($groupArray, $projArray));
} elseif (!empty($projArray)) {
    $c->where(array($projArray));
} elseif (!empty($groupArray)) {
    $c->where(array($groupArray));
}

<div>[[+total]] Products</div>
<form action="[[~[[*id]]]]" method="POST">
<p>Choose a Group or Groups:</p>
<div id="checka">
   <input type="checkbox" name="group[]" value="BRA" [[+BRA_checked]] id="checka1" onChange="this.form.submit();" />
   <label for="checka1">Brackets</label> 
   <input type="checkbox" name="group[]" value="BLK" [[+BLK_checked]] id="checka2" onChange="this.form.submit();" />
   <label for="checka2">Blocks</label> 
   <input type="checkbox" name="group[]" value="COR" [[+COR_checked]] id="checka3" onChange="this.form.submit();" />
   <label for="checka3">Corbels</label> 
   <input type="checkbox" name="group[]" value="GBR" [[+GBR_checked]] id="checka4" onChange="this.form.submit();" />
   <label for="checka4">Gingerbreads</label> 
   <input type="checkbox" name="group[]" value="WBR" [[+WBR_checked]] id="checka5" onChange="this.form.submit();" />
   <label for="checka5">Wood</label>
</div>
<p>Select Projection Dimensions from 0" to 9":</p>
<div id="checkb">
   <input type="checkbox" name="proj[]" value="0" [[+0_checked]] id="checkb0" onChange="this.form.submit();" />
   <label for="checkb0">0"</label> 
   <input type="checkbox" name="proj[]" value="1" [[+1_checked]] id="checkb1" onChange="this.form.submit();" />
   <label for="checkb1">1"</label> 
   <input type="checkbox" name="proj[]" value="2" [[+2_checked]] id="checkb2" onChange="this.form.submit();" />
   <label for="checkb2">2"</label> 
   <input type="checkbox" name="proj[]" value="3" [[+3_checked]] id="checkb3" onChange="this.form.submit();" />
   <label for="checkb3">3"</label> 
   <input type="checkbox" name="proj[]" value="4" [[+4_checked]] id="checkb4" onChange="this.form.submit();" />
   <label for="checkb4">4"</label> 
   <input type="checkbox" name="proj[]" value="5" [[+5_checked]] id="checkb5" onChange="this.form.submit();" />
   <label for="checkb5">5"</label> 
   <input type="checkbox" name="proj[]" value="6" [[+6_checked]] id="checkb6" onChange="this.form.submit();" />
   <label for="checkb6">6"</label> 
   <input type="checkbox" name="proj[]" value="7" [[+7_checked]] id="checkb7" onChange="this.form.submit();" />
   <label for="checkb7">7"</label> 
   <input type="checkbox" name="proj[]" value="8" [[+8_checked]] id="checkb8" onChange="this.form.submit();" />
   <label for="checkb8">8"</label> 
   <input type="checkbox" name="proj[]" value="9" [[+9_checked]] id="checkb9" onChange="this.form.submit();" />
   <label for="checkb9">9"</label>
</div>
</form>

$output = "";
 
$path = MODX_CORE_PATH . 'components/aeibbproducts/';
$result = $modx->addPackage('aeibbproducts',$path .
    'model/','aei_');
 
if (! $result) {
    return 'failed to add package';
}
 
$proj = array();
if (isset($_POST['proj']) && (! empty($_POST['proj']))) {
    $proj = $_POST['proj'];
}
 
$group = array();
if (isset($_POST['group']) && (! empty($_POST['group']))) {
    $group = $_POST['group'];
}
 
$checked = 'checked="checked"';
 
$c = $modx->newQuery('BbProducts');
 
$groupArray = array();
foreach($group as $selected) {
        $groupArray[] = array('pre' => $selected);
        $modx->setPlaceholder($selected . '_checked', $checked);
}
$projArray = array();
foreach($proj as $select) {
        $projArray[] = array('proj:LIKE' => $select.'.'.'%');
        $modx->setPlaceholder($select . '_checked', $checked);
}

if ((!empty($projArray)) && (!empty($groupArray))) {
    $c->where(array($groupArray, $projArray), xPDOQuery::SQL_OR);
} elseif (!empty($projArray)) {
    $c->where(array($projArray), xPDOQuery::SQL_OR);
} elseif (!empty($groupArray)) {
    $c->where(array($groupArray), xPDOQuery::SQL_OR);
}
 
$total = $modx->getCount('BbProducts',$c);
$totalVar = $modx->getOption('totalVar', $scriptProperties, 'total');
$modx->setPlaceholder($totalVar,$total);
 
$modx->runSnippet('FeetInch');
$fi = new FeetInch($modx);
 
$noImage ='assets/media/jpgs/noimage-s.jpg';
$products = $modx->getCollection('BbProducts',$c);
foreach($products as $product) {
    $fields = $product->toArray();
    $width = $product->get('width');
    $fields['nwW'] = 'Width: ' . $fi->dec2inch($width);
    $height = $product->get('height');
    $fields['nwH'] = 'Height: ' . $fi->dec2inch($height);
    $proj = $product->get('proj');
    $fields['nwP'] = 'Proj: ' . $fi->dec2inch($proj);
    $pitch = $product->get('pitch');
    $fields['nwPi'] = $pitch . ' Pitch';
    $fleName = $product->get('aei');
    $temp = 'assets/media/jpgs/prod-s/' . '01-' . $fleName . '.jpg';
    $fields['imgLink'] = file_exists($temp) ? $temp : $noImage;
    $output .= $modx->getChunk('showBrackets', $fields);
}

$msg1 = "\ngroupArray" . print_r($groupArray, true);
$modx->log(modX::LOG_LEVEL_ERROR, $msg1);

$msg2 = "\nprojArray" . print_r($projArray, true);
$modx->log(modX::LOG_LEVEL_ERROR, $msg2);

return $output;