Wordpress pods: Exporting specific columns to json - json

Question

I have the following code for exporting all the items in one of my pods to json. The thing is I don't need all the 130 columns in the json file, but only about 20. Since this will be done for about 150 items I thought I could save some loading time by not printing out all the fields, but I do not know how to do this. For example I only want to print the column value named 'title' for all items in the pod. My code is attached bellow.
<?php
$pods = pods('name', array('orderby' => 'name asc', 'limit' => -1));
$all_companies = $pods->export_data();
if ( !empty( $all_companies ) ) {
die(json_encode($all_companies);
}else{
die(json_encode(array('error' => 'No cars found.')));
}
?>
I thought about doing something like this:
if ( 0 < $all_companies->total() ) {
while ($all_companies->fetch()) {
$json .= $all_companies->field('title');
}
$json = rtrim($json, ",");
$json .= '}}';
}
echo $json;
But it doesn't work and also the code becomes very long.

Answer 1

I'd make an array of the names of the twenty fields you want then build an array of those fields for each item, by doing a foreach of those field names passed to Pods::field() inside the while loop. Like this:
$pods = pods('name', array('orderby' => 'name asc', 'limit' => -1));
$fields = array( 'field_1', 'field_2' );
if ( $pods->total() > 0 ) {
while ( $pods->fetch() ) {
foreach ( $fields as $field ) {
$json[ $pods->id() ] = $pods->field( $field );
}
}
$json = json_encode( $json );
}
Alternatively, you could hack the /pods/<pod> endpoint of our JSON API to accept a list of fields to return as the body of the request. Wouldn't be hard to do, make sure to submit a pull request if you make it work.