{"id":57985,"date":"2023-01-05T03:01:21","date_gmt":"2023-01-04T17:01:21","guid":{"rendered":"http:\/\/www.rjmprogramming.com.au\/ITblog\/?p=57985"},"modified":"2023-01-04T19:57:36","modified_gmt":"2023-01-04T09:57:36","slug":"geojson-world-countries-geo-chart-tutorial","status":"publish","type":"post","link":"https:\/\/www.rjmprogramming.com.au\/ITblog\/geojson-world-countries-geo-chart-tutorial\/","title":{"rendered":"GeoJson World Countries Geo Chart Tutorial"},"content":{"rendered":"
\"GeoJson<\/a>

GeoJson World Countries Geo Chart Tutorial<\/p><\/div>\n

There are many advantages regarding today’s task to …<\/p>\n

\nIntegrate Google Chart<\/a> Geo Chart<\/a>\n<\/p><\/blockquote>\n

… as an additional “drill down” map option, functionality adding onto the work of yesterday’s GeoJson World Countries Tutorial<\/a>.<\/p>\n

What deducible data item needs to be determined for these Geo Charts to work? We need a way to deduce ISO-2 character country codes from the ISO-3 character codes existing in the GeoJson “countries.geojson” data from yesterday’s work. We happened upon the extremely generous mapping data webpage<\/a> to help with these ISO-2 character deductions<\/font> …<\/p>\n

<?php
\n
\n$geojsonis=file_get_contents('countries.geojson');
\n$parts=explode(\"]]\", $geojsonis);
\n$globalattr=\"\";
\n$mappings=file_get_contents('ht<\/font>tp:\/\/gist.github.com\/tadast\/8827699'); \/\/ thanks
\nif (strpos($mappings, '>IN<\/td>') !== false) {
\n $mappings.='<td>IN<\/td><td>KAS<\/td><td>EH<\/td><td>SAH<\/td><td>SO<\/td><td>SOL<\/td><td>SS<\/td><td>SDS<\/td><td>XK<\/td><td>KOS<\/td><td>CY<\/td><td>CYN<\/td><\/body>';
\n}<\/font>
\n
\nfor ($i=0; $i<(-1 + sizeof($parts)); $i++) {
\n if (strpos($parts[$i], '\"sr_sov_a3\":\"') !== false) {
\n $globalattr=' data-iso3=\"' . explode('\"', explode('\"sr_sov_a3\":\"', $parts[$i])[1])[0] . '\"';
\n if (strpos($mappings, '>' . explode('\"', explode('\"sr_sov_a3\":\"', $parts[$i])[1])[0] . '<\/td>') !== false) {
\n $iparts=explode('>' . explode('\"', explode('\"sr_sov_a3\":\"', $parts[$i])[1])[0] . '<\/td>', $mappings);
\n $globalattr.=' data-iso2=\"' . explode('>', explode('<\/td>', $iparts[0])[-2 + sizeof(explode('<\/td>', $iparts[0]))])[-1 + sizeof(explode('>', explode('<\/td>', $iparts[0])[-2 + sizeof(explode('<\/td>', $iparts[0]))]))] . '\"';
\n } else if (substr(explode('\"', explode('\"sr_sov_a3\":\"', $parts[$i])[1])[0],-1,1) >= '0' && substr(explode('\"', explode('\"sr_sov_a3\":\"', $parts[$i])[1])[0],-1,1) <= '9') {
\n $globalattr.=' data-iso2=\"' . substr(explode('\"', explode('\"sr_sov_a3\":\"', $parts[$i])[1])[0],0,2) . '\"';
\n }
\n }
\n if (strpos($parts[$i], '\"sr_subunit\":\"') !== false) {
\n $globalattr.=' data-cname=\"' . explode('\"', explode('\"sr_subunit\":\"', $parts[$i])[1])[0] . '\"';
\n }
\n $coords=str_replace('[','',str_replace(']','',explode('[[' , $parts[$i])[-1 + sizeof(explode('[[' , $parts[$i]))]));
\n $newcoords=$coords;
\n if (!$dolatlong || 1 == 1) {
\n $lls=explode(\",\", $coords);
\n $newcoords=\"\";
\n for ($j=0; $j<sizeof($lls); $j+=2) {
\n $lls[$j]=($lls[$j] + $longoff) * $factor;
\n $lls[$j + 1]=($lls[$j + 1] + $latoff) * $factor;
\n if ($newcoords != \"\") { $newcoords.=\",\"; $htmlis=str_replace(\"}\", \" context.lineTo(\" . $lls[$j] . ',' . ((180.0 * $factor) - $lls[$j + 1]) . \"); \\n}\", $htmlis); } else { $htmlis=str_replace(\"}\", \" context.stroke(); \\n context.beginPath(); \\n context.moveTo(\" . $lls[$j] . ',' . ((180.0 * $factor) - $lls[$j + 1]) . \"); \\n}\", $htmlis); }
\n $newcoords.='' . $lls[$j] . ',' . ((180.0 * $factor) - $lls[$j + 1]);
\n }
\n }
\n $abit.=\"<area\" . $globalattr . \" onclick=\\\"ouralert(this.getAttribute('data-cname'),this.getAttribute('data-iso3'),this.getAttribute('data-iso2'),'Longitude,Latitude coordinates are \" . $coords . \"');\\\" shape='poly' coords='\" . $newcoords . \"'><\/area>\\n\";
\n \/\/echo \"<area type='poly' coords='\" . $newcoords . \"'><\/area>\\n\";
\n}
\n<\/code>
\n?><\/p>\n

… in our image map area elements PHP creation code above. As you can see, extra “intelligence”, moving forward, is contained in area element global data attributes<\/a>.<\/p>\n

Which leaves us with why any of this helps functionality within our changed<\/a> countries.php<\/a> web application<\/a> you can also try below<\/a>?<\/p>\n