如何将javascript变量传递给html表单操作标签

Question

I have an html form which contain name, longitude and latitude text field. The longitude and latitude are stored in a javascript variable. Do you know how post the name, latitude and longitude to a server, I mean via a url? Everytime I am submitting the form, the longitude and latitude are not passed into the url? Can anyone please tell me how to do that?

Thank you

This is my code for both my javascript and html:

    if (navigator.geolocation) {
    var geolocation = {};
    geolocation.latitude = 0;
    geolocation.longitude = 0;
    navigator.geolocation.getCurrentPosition(function (p) {
    geolocation.latitude = p.coords.latitude;
    geolocation.longitude = p.coords.longitude;           
    }, function (error) {
    alert("Failed to get GPS location");
    });
    } else {
    alert("Failed to get GPS working");
    }

    function loc() {
    document.getElementById("longitude").value = geolocation.latitude;
    document.getElementById("latitude").value = geolocation.longitude;

    }

html:

    <form name="photo" method="post" action="url">
    <label for="name">Name:</label>
    <input type="text" name="name" id="Text1" value="" />
    <label for="longitude">Longitude:</label>
    <input type="text" name="longitude" id="longitude" />
    <label for="latitude">Latitude:</label>
    <input type="text" name="latitude" id="latitude" />
    <label for="image">Image:</label>
    <input type="text" name="image" id="image" />
    <input type="submit" value="Submit" />
    </form>

Answer 1

You could add elements to the form...

var myForm = document.getElementById('myForm');

var longitude = document.createElement('input');
longitude.name= 'longitude';
longitude.value = '100';

var latitude= document.createElement('input');
latitude.name= 'latitude';
latitude.value = '100';

myForm.appendChild(longitude);
myForm.appendChild(latitude);

Answer 2

In the action of the form you need to mention the name of the servlet you want to call. Make use of three hidden fields to store the values name, longitude and latitude. This can be done using

document.getElementById('hiddenFieldId1').value=longitude; document.getElementById('hiddenFieldId2').value=latitude; document.getElementById('hiddenFieldId3').value=name;

These values can be referred in the servlet using request.getParameter('hiddenFieldId');

You need to submit the form in your js:

document.myform.submit();

geolocation variable hasn't been made global, so it is not defined in your function loc() . There are no values assigned to geolocation.latitude and geolocation.longitude .