apps/workbench/app/assets/javascripts/infinite_scroll.js

   1 function maybe_load_more_content() {
   2     var scroller = this;        // element with scroll bars
   3     var container;              // element that receives new content
   4     var src;                    // url for retrieving content
   5     var scrollHeight;
   6     var spinner, colspan;
   7     scrollHeight = scroller.scrollHeight || $('body')[0].scrollHeight;
   8     if ($(scroller).scrollTop() + $(scroller).height()
   9         >
  10         scrollHeight - 50) {
  11         container = $(this).data('infinite-container');
  12         src = $(container).attr('data-infinite-content-href');
  13         if (!src)
  14             // Finished
  15             return;
  16         // Don't start another request until this one finishes
  17         $(container).attr('data-infinite-content-href', null);
  18         spinner = '<div class="spinner spinner-32px spinner-h-center"></div>';
  19         if ($(container).is('table,tbody,thead,tfoot')) {
  20             // Hack to determine how many columns a new tr should have
  21             // in order to reach full width.
  22             colspan = $(container).closest('table').
  23                 find('tr').eq(0).find('td,th').length;
  24             if (colspan == 0)
  25                 colspan = '*';
  26             spinner = ('<tr class="spinner"><td colspan="' + colspan + '">' +
  27                        spinner +
  28                        '</td></tr>');
  29         }
  30         $(container).append(spinner);
  31         $.ajax(src,
  32                {dataType: 'json',
  33                 type: 'GET',
  34                 data: {},
  35                 context: {container: container, src: src}}).
  36             always(function() {
  37                 $(this.container).find(".spinner").detach();
  38             }).
  39             fail(function(jqxhr, status, error) {
  40                 if (jqxhr.readyState == 0 || jqxhr.status == 0) {
  41                     message = "Cancelled."
  42                 } else if (jqxhr.responseJSON && jqxhr.responseJSON.errors) {
  43                     message = jqxhr.responseJSON.errors.join("; ");
  44                 } else {
  45                     message = "Request failed.";
  46                 }
  47                 // TODO: report this to the user.
  48                 console.log(message);
  49                 $(this.container).attr('data-infinite-content-href', this.src);
  50             }).
  51             done(function(data, status, jqxhr) {
  52                 $(this.container).append(data.content);
  53                 $(this.container).attr('data-infinite-content-href', data.next_page_href);
  54             });
  55     }
  56 }
  57 $(document).
  58     on('ready ajax:complete', function() {
  59         $('[data-infinite-scroller]').each(function() {
  60             var $scroller = $($(this).attr('data-infinite-scroller'));
  61             if (!$scroller.hasClass('smart-scroll') &&
  62                 'scroll' != $scroller.css('overflow-y'))
  63                 $scroller = $(window);
  64             $scroller.
  65                 addClass('infinite-scroller').
  66                 data('infinite-container', this).
  67                 on('scroll', maybe_load_more_content);
  68         });
  69     });