static function mergeField($fieldName, $existingValue, $newValue)
{
if ($newValue === null) {
return $existingValue;
} elseif ($existingValue === null) {
return $newValue;
} elseif ($existingValue === $newValue) {
return $existingValue;
}
$appendWithNewlineFields = array('summary', 'notes');
$appendWithSpaceFields = array('name_suffix', 'name_prefix');
$dateFields = array('start_date', 'end_date');
$nameFields = array('name_first', 'name_middle');
$numberFields = array('employees', 'revenue', 'endowment');
if (in_array($fieldName, $appendWithNewlineFields)) {
return $existingValue . "\n\n" . $newValue;
} elseif (in_array($fieldName, $appendWithSpaceFields)) {
return $existingValue . ' ' . $newValue;
} elseif (in_array($fieldName, $dateFields)) {
$existingDate = new LsDate($existingValue);
$newDate = new LsDate($newValue);
if ($existingDate->howSpecific() > $newDate->howSpecific()) {
return $existingDate->format();
} elseif ($existingDate->howSpecific() < $newDate->howSpecific()) {
return $newDate->format();
} else {
if ($existingDate->howSpecific() == LsDate::YEAR_SPECIFIC) {
return LsDate::lessOrEqual($existingDate, $newDate) ? $existingDate : $newDate;
} else {
return $existingDate;
}
}
} elseif (in_array($fieldName, $nameFields)) {
return strlen($existingValue) >= strlen($newValue) || strlen($existingValue) !== 1 ? $existingValue : $newValue;
} elseif (in_array($fieldName, $numberFields)) {
return $existingValue == 0 ? $newValue : $existingValue;
} else {
return $existingValue;
}
}