我想在我的登陆页面上创建一个函数来获取用户位置并计算最近的商店并将其显示在页面上..我使用此代码来计算..
var cities = [
["city1", 10, 50, "blah"],
["city2", 40, 60, "blah"],
["city3", 25, 10, "blah"],
];
function NearestCity(latitude, longitude) {
var mindif = 99999;
var closest;
for (index = 0; index < cities.length; ++index) {
var dif = PythagorasEquirectangular(latitude, longitude, cities[index][1], cities[index][2]);
if (dif < mindif) {
closest = index;
mindif = dif;
}
}
alert(cities[closest]);
}
如何将结果传递给php并存储到数据库？
最佳答案
要从 NearestCity 函数传递数据，您通常会使用 ajax - 请求可以发送到同一页面或另一个页面，具体取决于您自己的偏好。下面显示了如何将数据发送到同一页面以供 PHP 代码使用 - 在这种情况下，它不会将信息保存到数据库，但它可以非常轻松地做到这一点。
<?php
if( $_SERVER['REQUEST_METHOD']=='POST' ){
ob_clean();
/* read and process ajax post request - available through the "$_POST" array */
/* add to db or whatever */
/*
send response to ajax callback
Here it is just a simple output showing the data that was sent via POST
but should be more meaningful ~ perhaps db results or html content etc
*/
echo implode( PHP_EOL, $_POST );
exit();
}
?>
<!doctype html>
<html>
<head>
<title>Find nearest - send via ajax to same page</title>
<script>
var defaults={
lat:52.628593,
lng:1.296380
};
var cities = [
['Aylsham', 52.794847, 1.252565, 'Aylsham is a historic market town and civil parish on the River Bure in north Norfolk, England'],
['North Walsham', 52.823477, 1.390931, 'North Walsham is a market town and civil parish in Norfolk, England within the North Norfolk district'],
['Dereham', 52.681311, 0.939737, 'Dereham, also known as East Dereham, is a town and civil parish in the English county of Norfolk'],
['Cambridge',52.204548, 0.124404,'Cambridge is a city on the River Cam in eastern England, home to the prestigious University of Cambridge, dating to 1209'],
['Swanton Morley',52.714710, 0.986908,'Swanton Morley is a village and civil parish situated in the English county of Norfolk']
];
function Deg2Rad(deg) {
return deg * Math.PI / 180;
}
function PythagorasEquirectangular(lat1, lon1, lat2, lon2) {
lat1 = Deg2Rad(lat1);
lat2 = Deg2Rad(lat2);
lon1 = Deg2Rad(lon1);
lon2 = Deg2Rad(lon2);
var R = 6371; // km
var x = (lon2 - lon1) * Math.cos((lat1 + lat2) / 2);
var y = (lat2 - lat1);
var d = Math.sqrt(x * x + y * y) * R;
return d;
}
function NearestCity( _latitude, _longitude ) {
var mindif = 99999;
var closest;
var tmp=[];
console.info('Find nearest city based upon lat:%s and lng:%s',_latitude, _longitude);
for ( var i=0; i < cities.length; i++ ) {
var _lat=cities[i][1];
var _lng=cities[i][2];
var difference = PythagorasEquirectangular( _latitude, _longitude, _lat, _lng );
if( difference < mindif ) {
closest = i;
mindif = difference;
tmp.push( cities[ i ] );
}
}
/* send request to the same page! */
ajax.call( this, location.href, tmp, cbNearestCity );
}
function ajax( url, params, callback ){
var xhr=new XMLHttpRequest();
xhr.onreadystatechange=function(){
if( xhr.readyState==4 && xhr.status==200 ){
callback.call( this, this.response );
}
};
var payload=[];
for( var n in params )payload.push( params[n][0]+'='+params[n] );
xhr.open( 'post', url, true );
xhr.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
xhr.setRequestHeader('X-Requested-With','XMLHttpRequest');
xhr.send( payload.join('&') );
}
function cbNearestCity(response){
document.getElementById('results').innerHTML=response;
}
document.addEventListener('DOMContentLoaded',function(e){
if( navigator.geolocation ){
navigator.geolocation.getCurrentPosition( function( pos ){
NearestCity.call( this, pos.coords.latitude, pos.coords.longitude );
});
} else {
NearestCity.call( this, defaults.lat, defaults.lng );
}
},{ capture:false, passive:true } );
</script>
</head>
<body>
<h1>Find nearest city - using geolocation on page load</h1>
<pre id='results'></pre>
</body>
</html>
关于javascript - 在同一页面中将数据从 javascript 传递到 php，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45453231/