PHP：使用来自php的参数调用javascript函数 [英] PHP: calling javascript function with parameters from php
问题描述
我试图用PHP变量的参数调用JavaScript函数。
我尝试了两种方法。
I am trying to call JavaScript function with parameter that are PHP variables. I have tried 2 approaches.
-
使用echo
中的script标签在PHP中调用JavaScript函数
calling JavaScript function in PHP with script tags in echo i.e
<?php
echo '<script>initialize('.$lat.','.$lang.','.$zom.');</script>';
?>
将PHP变量赋值给JavaScript变量
assigning PHP variables values to JavaScript variables
<script>
var lat="<?php echo $lat;?>";
var lang="<?php echo $lang; ?>";
var zoom="<?php echo $zoom; ?>";
alert(lat+lang+zoom);
initialize(lat,lang,zoom);
</script>
函数被调用，因为我从页面源进行交叉检查，但传递的参数未定义。
在第二种情况下，值被成功保存在JavaScript变量中，通过alert（）来检查，但函数没有被调用。
In first case function is called as I cross-checked from page source but parameters passed are undefined. And in 2nd case values are successfully saved in JavaScript variables, check it by alert(), but function is not called.
这是整个代码：
Here is the whole code:
<!DOCTYPE html>
<html>
<head>
<script src="http://maps.googleapis.com/maps/api/js?key=AIzaSyDY0kkJiTPVd2U7aTOAwhc9ySH6oHxOIYM&sensor=false">
</script>
<?php
if( isset($_POST['lat']) && isset($_POST['lang']) && isset($_POST['zoom']) && isset($_POST['city'])):
$lat=$_POST['lat'];
$lang=$_POST['lang'];
$zoom=$_POST['zoom'];
$city=$_POST['city'];
$zom=(int)$zoom;
var_dump($lang);
var_dump($lat);
//var_dump($zoom);
var_dump($zom);
//echo '<script>initialize('.$lat.','.$lang.','.$zom.');</script>';
endif;
?>
<script>
var lat="<?php echo $lat; ?>";
var lang="<?php echo $lang; ?>";
var zoom="<?php echo $zoom; ?>";
alert(lat+lang+zoom);
initialize(lat,lang,zoom);
</script>
<script>
function initialize(a,b,zom){
if (!a || !b ||!zom){
alert('came on not' +a+b +zom);
// var centerLoc=new google.maps.LatLng( 33.61701054652337,73.37824736488983);
zoom=16;
}
else
{
alert('came');
var zoom =parseInt(zom);
var centerLoc=new google.maps.LatLng(a,b);
}
var mapProp = {
center:centerLoc,
zoom:zoom,
//mapTypeId:google.maps.MapTypeId.ROADMAP
mapTypeId:google.maps.MapTypeId.SATELLITE
};
var map=new google.maps.Map(document.getElementById("googleMap") ,mapProp);
marker=new google.maps.Marker({
position:centerLoc,
title:'Click to zoom'
});
google.maps.event.addListener(marker,'click',function() {
map.setZoom(map.getZoom()+1);
map.setCenter(marker.getPosition());
});
marker.setMap(map);
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body style= "background-color:gainsboro;">
<form method="POST" action="myPage.php" >
Enter latitude: <input type ="text" name="lat" id="lat" / ><br/>
Enter longitude: <input type ="text" name="lang" id="lang"/ ><br/>
Enter City Name: <input type="text" name="city" id="city"/><br/>
Enter Zoom level: <input type ="text" name="zoom" id="zoom"/ ><br/>
<input type="button" value ="Perview" onclick=" initialize(
document.getElementById('lat').value,
document.getElementById('lang').value,
document.getElementById('zoom').value)"/>
<input type="Submit" value="Save" />
</form>
<center><div id="googleMap" style="width:1000px;height:500px;"></div></center>
</body>
</html>
推荐答案
使用 json_encode（） 。如果你不这样做，那么在你从PHP到HTML / JS层传递数据时，你将永远有可能错误地将你的数据转义。
Use json_encode(). If you don't there will always be the possibility you escaped your data incorrectly as it passes from the PHP to the HTML/JS layer.
$vars = array($lat, $lang, $zoom);
// JSON_HEX_TAG and JSON_HEX_AMP are to remove all possible surprises that could be
// caused by vars that contain '</script>' or '&' in them. The rules for
// escaping/encoding inside script elements are complex and vary depending
// on how the document is parsed.
$jsvars = json_encode($vars, JSON_HEX_TAG | JSON_HEX_AMP);
echo "<script>initialize.apply(null, $jsvars)</script>";
一般来说，为了您的理智，PHP中需要提供给js的所有数据运行在当前页面上应该被收集到一个PHP数组中，然后放入一个js对象中。例如：
In general, for your sanity, all data that is in PHP that you need to make available to js running on the current page should be collected into a single PHP array and then placed into a single js object. For example:
<?php
$jsdata = array(
'formvars' => array(
'lat' => $lat,
'lang' => $lang,
'zoom' => $zoom
),
'username' => $username,
'some_other_data' => $more stuff
);
?>
<script>
var JSDATA = <?=json_encode($jsdata, JSON_HEX_TAG | JSON_HEX_AMP )?>;
initialize(JSDATA.formvars.lat, JSDATA.formvars.lang, JSDATA.formvars.zoom);
</script>
现在JS和PHP / HTML图层之间只有一个单一的联系点，所以您可以轻松地跟踪您将要放入JS命名空间的内容。
Now there is only a single point of contact between the JS and PHP/HTML layers so you can easily keep track of what you are putting into the JS namespace.
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