在PHP中覆盖API和json输出

Question

I am using Overpass Turbo to show information on a map. Part of my code (I use PHP) is as follows:

//overpass query
$overpass = 'http://overpass-api.de/api/interpreter?data=[out:json];area(3600046663)->.searchArea;(node["amenity"="drinking_water"](area.searchArea););out;';
// collecting results in JSON format
$html = file_get_contents($overpass);
$jsonout = json_decode($html);
// this line just checks what the query would give as output
var_dump($jsonout);

Query results in JSON format (which is what var_dump shows) look like this:

version:    0.6
generator:  "Overpass API"
osm3s:
timestamp_osm_base: "2017-11-03T06:25:02Z"
timestamp_areas_base:   "2017-11-03T05:45:02Z"
copyright:  "The data included in this document is from www.openstreetmap.org. The data is made available under ODbL."
elements:   
0:
type:   "node"
id: 254917402
lat:    46.0672187
lon:    11.1379545
tags:   
amenity:    "drinking_water"
1:
type:   "node"
id: 257481472
lat:    46.0687113
lon:    11.1201097
tags:   
amenity:    "drinking_water"

and so on.

You can see it yourself, copying/pasting the query URL in your browser: http://overpass-api.de/api/interpreter?data=[out:json];area(3600046663)-%3E.searchArea;(node[%22amenity%22=%22drinking_water%22](area.searchArea););out;

As you can see, each element in the array above has latitude and longitude information. I need those to show markers on a map.

I am not able to isolate the lat and lon information from each element in the array. How can I do that?

Answer 1

Here you go:

<?php

// overpass query
$overpass = 'http://overpass-api.de/api/interpreter?data=[out:json];area(3600046663)->.searchArea;(node["amenity"="drinking_water"](area.searchArea););out;';

// collecting results in JSON format
$html = file_get_contents($overpass);
$result = json_decode($html, true); // "true" to get PHP array instead of an object

// elements key contains the array of all required elements
$data = $result['elements'];

foreach($data as $key => $row) {

    // latitude
    $lat = $row['lat'];

    // longitude
    $lng = $row['lon'];
}

?>