Processing results from fatfree DB SQL Mapper for json encoding - json

Question

I'm having trouble processing the returned results from a DB SQL Mapper into a recognizable json encoded array.
function apiCheckSupplyId() {
/*refer to the model Xrefs*/
$supply_id = $this->f3->get('GET.supply_id');
$xref = new Xrefs($this->tongpodb);
$supply = $xref->getBySupplyId( $supply_id );
if ( count( $supply ) == 0 ) {
$this->logger->write('no xref found for supply_id=' .$supply_id);
$supply = array( array('id'=>0) );
echo json_encode( $supply );
} else {
$json = array();
foreach ($supply as $row){
$item = array();
foreach($row as $key => $value){
$item[$key] = $value;
}
array_push($json, $item);
}
$this->logger->write('xref found for supply_id=' .$supply_id.json_encode( $json ) );
echo json_encode( $json );
}
}
This is the method I am using but it seems very clunky to me. Is there a better way?

Answer 1

Assuming the getBySupplyId returns an array of Xref mappers, you could simplify the whole thing like this:
function apiCheckSupplyId() {
$supply_id = $this->f3->get('GET.supply_id');
$xref = new Xrefs($this->tongpodb);
$xrefs = $xref->getBySupplyId($supply_id);
echo json_encode(array_map([$xref,'cast'],$xrefs));
$this->logger->write(sprintf('%d xrefs found for supply_id=%d',count($xrefs),$supply_id));
}
Explanation:
The $xrefs variable contains an array of mappers. Each mapper being an object, you have to cast it to an array before encoding it to JSON. This can be done in one line by mapping the $xref->cast() method to each record: array_map([$xref,'cast'],$xrefs).
If you're not confident with that syntax, you can loop through each record and cast it:
$cast=[];
foreach ($xrefs as $x)
$cast[]=$x->cast();
echo json_encode($cast);
The result is the same.
The advantage of using cast() other just reading each value (as you're doing in your original script) is that it includes virtual fields as well.