我正在尝试创建一个交互式搜索引擎(用于查找活动门票),其中一个功能是使用 OpenLayers 显示相关场地的可视化地图。我在一个 kml 文件中有大量场地(3000+),我想选择性地显示一个过滤的小节。下面是我的代码,但是当我尝试运行它时出现 JavaScript 错误。运行 firebug 和 chrome 开发人员工具让我认为它没有传递我提供的参数,因为它说变量为空。但是,我无法弄清楚为什么他们没有通过。非常感谢任何见解。
var map, drawControls, selectControl, selectedFeature, select;
$('#kml').load('venuesComplete.kml');
kml=$('#kml').html();
function showVenues(state, city, venue){
filterStrategy = new OpenLayers.Strategy.Filter({});
var kmllayer = new OpenLayers.Layer.Vector("KML", {
strategies: [filterStrategy,
new OpenLayers.Strategy.Fixed()],
protocol: new OpenLayers.Protocol.HTTP({
url: "venuesComplete.kml",
format: new OpenLayers.Format.KML({
extractStyles: true,
extractAttributes: true
})
})
});
select = new OpenLayers.Control.SelectFeature(kmllayer);
kmllayer.events.on({
"featureselected": onFeatureSelect,
"featureunselected": onFeatureUnselect
});
map.addControl(select);
select.activate();
filter = new OpenLayers.Filter.Comparison({
type: OpenLayers.Filter.Comparison.LIKE,
property: "",
value: ""
});
function clearFilter(){
filterStrategy.setFilter(null);
}
function setFilter(property, value){
filter.value = value;
filter.property = property;
filterStrategy.setFilter(filter);
}
var vector_style = new OpenLayers.Style();
if(venue!=""){
setFilter('name', venue);
}else if(city!=""){
setFilter('description', city);
}else if(state!=""){
setFilter('description', state);
}
map.addLayer(kmllayer);
function onPopupClose(evt) {
select.unselectAll();
}
function onFeatureSelect(event) {
var feature = event.feature;
var selectedFeature = feature;
var popup = new OpenLayers.Popup.FramedCloud("chicken",
feature.geometry.getBounds().getCenterLonLat(),
new OpenLayers.Size(100,100),
"<h2>"+feature.attributes.name + "</h2>" + feature.attributes.description +'<br>'+feature.attributes,
null,
true,
onPopupClose
);
document.getElementById('venueName').value=feature.attributes.name;
document.getElementById("output").innerHTML=event.feature.id;
feature.popup = popup;
map.addPopup(popup);
}
function onFeatureUnselect(event) {
var feature = event.feature;
if(feature.popup) {
map.removePopup(feature.popup);
feature.popup.destroy();
delete feature.popup;
}
}
}
function init() {
map = new OpenLayers.Map('map');
var google_map_layer = new OpenLayers.Layer.Google(
'Google Map Layer',
{type: google.maps.MapTypeId.HYBRID}
);
map.addLayer(google_map_layer);
state="";
state+=document.getElementById('stateProvDesc').value;
city="";
city+=document.getElementById('cityZip').value;
venue="";
venue+=document.getElementById('venueName').value;
showVenues(state,city,'Michie Stadium');
map.addControl(new OpenLayers.Control.LayerSwitcher({}));
map.zoomToMaxExtent();
}