Processwire JSON example

gistfile1.php

<?php 
	$projects = $pages->find('template=project-detail, sort=sort');
	$projects_array = array();

	foreach ($projects as $project) {

		$title = $project->title;
		$summary = $project->project_summary;
		$long = $project->project_location_marker_long;
		$lat = $project->project_location_marker_lat;

		$projects_array[] = array(
			'type' => 'Feature',
			'geometry' => array(
				'type' => 'Point',
				'coordinates' => [$long,$lat]
			),
			'properties' => array(
				'title' => $title,
				'description' => $summary,
				'marker-color' => '#ffff00',
				'marker-size' => 'large',
				'marker-symbol' => 'monument',
			),
		);
		
	}

	$projects_json = json_encode($projects_array, true);
	?>
	<script>
	var geojson = <?php echo $projects_json; ?>
	</script>