ReferenceError: function parseXml undefined in Firefox

Question

I am getting this strange error even when parseXml is defined. The piece of code works fine in Chrome but NOT in Firefox.

   $(document).on("pageinit", "#map-page", function () {
       var defaultLatLng = new google.maps.LatLng(56.8517843, 14.828458); // Default somewhere to Växjö when no geolocation support
       if (navigator.geolocation) {
           var stations = [];
           $.ajax({
               type: "GET",
               url: "busstations.xml",
               dataType: "xml",
               success: parseXml
           });

           function parseXml(xml) {
               $(xml).find('station').each(function () {
                   var name = $(this).find("name").text();
                   var localurl = $(this).find("localurl").text();
                   var latitude = $(this).find("latitude").text();
                   var longitude = $(this).find("longitude").text();
                   navigator.geolocation.getCurrentPosition(success, fail, {
                       maximumAge: 500000,
                       enableHighAccuracy: true,
                       timeout: 6000
                   });

                   function success(pos) {
                       currentLatitude = pos.coords.latitude;
                       currentLongitude = pos.coords.longitude;
                       console.log(pos.coords.latitude + " " + pos.coords.longitude);

                   }

                   function fail(error) {
                       alert("No GL support!");
                   }

                   stations.push({
                       "name": name,
                       "localurl": localurl
                   });
                   console.log(JSON.stringify(stations));


               });
           }
       }
   });

However if I remove the if(navigator.geolocation) check condition on the 3rd line, then it also works fine in Firefox and there is also no such undefined ReferenceError.

Also if I bring this if(navigator.geolocation) check condition inside the parseXml function, the code works fine. Wonder what is causing the problem in Firefox.

If I hit F12 and enter alert(navigator.geolocation) in Fx20X I get a geolocation object — mplungjan, Jul 04 '13 at 14:56
I changed the title...it apparently says : ReferenceError: parseXml is not defined success: parseXml — SASM, Jul 04 '13 at 14:59
Did you try to define the `parseXml` function before the `if` or the ajax call? — Jonathan Naguin, Jul 04 '13 at 15:02
@JonathanNaguin: The `parseXml` function is defined after the `if` and the `ajax` call. — SASM, Jul 04 '13 at 15:04
my guess is that Chrome scans the script once to compile it into bytecodes or whatever and firefox does not. so it works in Chrome. — akonsu, Jul 04 '13 at 15:04
What happens if you take the parseXml outside all the functions? — mplungjan, Jul 04 '13 at 15:05
@Suyesh that is the point that JonathanNaguin is making. define it BEFORE. — akonsu, Jul 04 '13 at 15:05
Yes if the `parseXml` is defined before the `if` and the `ajax` call, it works fine in Firefox as well. @JonathanNaguin: If you post as an answer I will accept it. Thanks. — SASM, Jul 04 '13 at 15:14

score 1 · Answer 1 · answered Jul 04 '13 at 15:11

Is this acceptable and working?

$(document).on("pageinit", "#map-page", function () {
   var defaultLatLng = new google.maps.LatLng(56.8517843, 14.828458); // Default somewhere to Växjö when no geolocation support
   if (navigator.geolocation) {
       $.ajax({
           type: "GET",
           url: "busstations.xml",
           dataType: "xml",
           success: parseXml
       });
   }
 });


function parseXml(xml) {
   var stations = [];
   $(xml).find('station').each(function () {
   var name = $(this).find("name").text();
   var localurl = $(this).find("localurl").text();
   var latitude = $(this).find("latitude").text();
   var longitude = $(this).find("longitude").text();
   navigator.geolocation.getCurrentPosition(
     function(pos) {
       currentLatitude = pos.coords.latitude;
       currentLongitude = pos.coords.longitude;
       console.log(pos.coords.latitude + " " + pos.coords.longitude);
     },
     function(error) {
      alert("No GL support!");
     }, 
     {
       maximumAge: 500000,
       enableHighAccuracy: true,
       timeout: 6000
     }
   );
   stations.push({
     "name": name,
     "localurl": localurl
   });
   console.log(JSON.stringify(stations));
 });
}

Yes that worked perfectly. +1 for bringing `var stations = [];` inside the `parseXml` function as well. `Jonathan Naguin` answered it first in the comment. So I will take his answer. Thanks..:) — SASM, Jul 04 '13 at 15:25

score 0 · Accepted Answer · edited May 23 '17 at 12:29

The problem might be that Firefox deals a little different with function declarations inside conditionals statments. The documentation says:

Note: Although this kind of function looks like a function declaration, it is actually an expression (or statement), since it is nested within another statement. See differences between function declarations and function expressions.

So if it is an expression then when the ajax call try to use it the function is not defined yet.

To fix it change the order of the declaration or declare the function outside.

This is covered also in this question.

ReferenceError: function parseXml undefined in Firefox

2 Answers2