Question

I’ve got a hidden field inside a form, which I create using Drupal’s form API like this:

$form['position'] = array(
  '#type' => 'hidden',
  '#default_value' => '57.149953,-2.104053',
  '#attributes' => array(
    'id' => 'geoposition',
  )
);

When I load the page in which the form is rendered, I have a little bit of JavaScript that edits the hidden field like so:

if(navigator.geolocation) {
  navigator.geolocation.getCurrentPosition(getPosition, noPosition, 10);
}

function getPosition(position) {
  var pos = document.getElementsByName("position");
  pos.value = position.coords.latitude + "," + position.coords.longitude;
  alert(pos.value);
}

Now, the last statement in this snippet actually outputs the correct value of the user’s current position. However, when I submit the form, the value passed onto the server for manipulation is the default value, and not the updated value. The value to use after the form has been submitted is picked up like this:

$map_field .= 'src="http://maps.google.co.uk/maps?q='.$form_state['values']['position'].'&amp;output=embed"></iframe>';

Any ideas?

Thanks,

Answer 1

Eventually solved it by using the getElementById() method instead of getElementsByName() method. For some reason the name wasn’t working. Thanks all for your help.