douyingyu5573
2012-02-13 11:05
浏览 135
已采纳

php代码调用javascript函数返回函数未定义

The code bellow tries to ask the user to upload kml file and then saves the file at the same time it shows the kml data in google maps using google maps api v2. I could successfully take the kml file and saves it at a specific directory, HOWEVER, i am facing some problem in displaying the file on google maps immediately after the user clicks on KML TEST button. The error is Uncaught ReferenceError: showKML is not defined

Here is the code that I used

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>Find latitude and longitude with Google Maps</title>   
    <script src="http://maps.google.com/maps?file=api&amp;v=2&amp;key=ABQIAAAAgrj58PbXr2YriiRDqbnL1RSqrCjdkglBijPNIIYrqkVvD1R4QxRl47Yh2D_0C1l5KXQJGrbkSDvXFA"
      type="text/javascript"></script>  

    <?php
    $upload = $_SERVER['PHP_SELF'];
    if(isset($_POST['kmltest'])) {
    $target_path = "uploads/";
    $fn =  basename( $_FILES['uploadedfile']['name']);

    $target_path = $target_path . basename( $_FILES['uploadedfile']['name']);
    //echo $target_path ;
    if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
    echo "The file ". basename( $_FILES['uploadedfile']['name']). " has been uploaded";
    echo "<script type=\"text/javascript\"> showKML(); </script>";


    } 
    else{
    echo "There was an error uploading the file, please try again!";
    }


}
?>

    <script src="egeoxml.js" type="text/javascript"></script>
    <script  type="text/javascript">

    var map;
    var options = {};
    var shapeCounter_ = 0;


        function initialize() {
        if (GBrowserIsCompatible()) {
            map = new GMap2(document.getElementById("map"));
            map.setCenter(new GLatLng(25.22903, 55.46612), 13);
            map.addControl(new GSmallMapControl());
            map.addControl(new GMapTypeControl());
            map.clearOverlays();
            document.getElementById("lat").value = "25.22903";
            document.getElementById("lng").value = "55.46612";
        }
    }




    function startShape() {
        initialize();
        document.getElementById('lat').disabled = true;
        document.getElementById('lng').disabled = true;
        var polygon = new GPolygon([],"ff0000", 2, 0.7,"ff0000",0.2);
        startDrawing(polygon, "Shape " + (++shapeCounter_), function() {
            var cell = this;
            var area = polygon.getArea();
            cell.innerHTML = (Math.round(area / 10000) / 100) + "km<sup>2</sup>";
            });
        showcoor(polygon);
    }

    function startDrawing(poly, name, onUpdate) {
        map.addOverlay(poly);
        poly.enableDrawing(options);
        poly.enableEditing({onEvent: "mouseover"});
        poly.disableEditing({onEvent: "mouseout"});
        GEvent.addListener(poly, "endline", function() {
            GEvent.addListener(poly, "click", function(latlng, index) {
                if (typeof index == "number") {
                    poly.deleteVertex(index);
                }    
            });
        });    
    }

    function showcoor (poly) {
        GEvent.addListener(poly, "endline", function() {
            GEvent.addListener(poly, "click", function() {
                var str= "" ;
                for (var i = 0, I = this.getVertexCount(); i < I; ++i) {
                    var xy = this.getVertex(i);
                    str += xy.lat() + ', ' + xy.lng() + '<br />';
                }
                alert (str);
            });
        });
    }

    function drawpoint() {
        //initialize();
        document.getElementById('lat').disabled = false;
        document.getElementById('lng').disabled = false;
        var lat = document.getElementById('lat').value;
        var lng = document.getElementById('lng').value;
        var center = new GLatLng(parseFloat(lat),   parseFloat (lng));
        map.setCenter(center, 7);
        geocoder = new GClientGeocoder();
        var marker = new GMarker(center, {draggable: true});  
        map.addOverlay(marker);
        GEvent.addListener(marker, "dragend", function() {
            var point = marker.getPoint();
            map.panTo(point);
            document.getElementById("lat").value = center.lat().toFixed(5);
            document.getElementById("lng").value = center.lat().toFixed(5);
        });
        GEvent.addListener(map, "moveend", function() {
            map.clearOverlays();
            var center = map.getCenter();
            var marker = new GMarker(center, {draggable: true});
            map.addOverlay(marker);
            document.getElementById("lat").value = center.lat().toFixed(5);
            document.getElementById("lng").value = center.lng().toFixed(5);
            GEvent.addListener(marker, "dragend", function() {
                var point =marker.getPoint();
                map.panTo(point);
                document.getElementById("lat").value = point.lat().toFixed(5);
                document.getElementById("lng").value = point.lng().toFixed(5);
            });
        });
    }

    function showKML() {
    //alert(filename);
        initialize();
        document.getElementById('lat').disabled = true;
        document.getElementById('lng').disabled = true;
        var exml;
        exml = new EGeoXml("exml", map, ("uploads/test.kml"));
        exml.parse();
        exml.show(); 
    }



    </script>


    </head> 
<body onload="initialize()" onunload="GUnload()" >
 <form action = <?php echo $upload; ?> method = "post"  enctype="multipart/form-data"/>
 <p align="left">

 <table>
  <tr>
    <td><b>Latitude</b></td>
    <td><b>Longitude</b></td>
  </tr>
  <tr>
    <td> 
    <input type="text" name="lat" id="lat" /></td>
    <td>
    <input type="text" name="lng" id="lng" /></td>
    <td>
    <input type="button" name="point" id="point" value="Point" onclick="drawpoint()" /><td>

    <input type="button" name="shape_b" id="shape_b" value="Poly" onclick="startShape()" /><td>



    <input type="submit" name="kmltest" id="kmltest" value="KML TEST" /> </td></tr>
    <tr>
    <td>
     <input type="file" name="uploadedfile" id="uploadedfile" />
    </td>
    </tr>



</table>
 </p>
  <p>
  <div align="center" id="map" style="width: 600px; height: 400px"><br/></div>
   </p>

  <script type="text/javascript">
//<![CDATA[
if (typeof _gstat != "undefined") _gstat.audience('','pagesperso-orange.fr');
//]]>
</script>

</form>

</body>

</html>

your assistance is highly appreciated

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2条回答 默认 最新

  • doucuyu2259 2012-02-13 11:13
    已采纳

    JavaScript <script> blocks are evaluated in blocks.

    Within the same block, a function can be called before it's defined, because function declarations are evaluated before the rest of the code.

    However, when you move function showKML(){} to a different block, the function is called before it's defined, hence the error.

    To solve the problem, you have to move the function declaration before the <?php .. ?> block, where showKML is called.

    A JSFiddle to demonstrate the problem: http://jsfiddle.net/SGbfu/1/


    More detailled explanation:
    1. When <script> and </script> is encountered, the code between is directly evaluated.
    2. All functions, declared using function x(){} are evaluated first. Then, the rest of the code is considered.
    3. Step 1-2 is repeated, till all <script> blocks in the document are evaluated.

    Example:

    <script>
    f(); // No error, f is declared below
    function f(){ alert('f() called'); }
    g(); // Error: g is not defined before, or within this block
    </script>
    <script>
    function g(){}
    </script>
    
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  • douqianni4080 2012-02-13 11:12

    you need to move the <script> block with the function definitions to the top. At the time you call the function showKML() its not yet defined. You should bind showKML() to the document ready event. (e.g. put the function call inside your initialize() function that is already called on the page load event)

    Also i suggest you move the javascript code definition to an external file and include it just like you include the google maps API - this avoids loading the code with each page refresh and reduces traffic and page load.

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