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

   1 function maybe_load_more_content(event) {
   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     var serial = Date.now();
   8     scrollHeight = scroller.scrollHeight || $('body')[0].scrollHeight;
   9     if ($(scroller).scrollTop() + $(scroller).height()
  10         >
  11         scrollHeight - 50)
  12     {
  13         $container = $(event.data.container);
  14         if (!$container.attr('data-infinite-content-href0')) {
  15             // Remember the first page source url, so we can refresh
  16             // from page 1 later.
  17             $container.attr('data-infinite-content-href0',
  18                             $container.attr('data-infinite-content-href'));
  19         }
  20         src = $container.attr('data-infinite-content-href');
  21         if (!src || !$container.is(':visible'))
  22             // Finished
  23             return;
  24
  25         // Don't start another request until this one finishes
  26         $container.attr('data-infinite-content-href', null);
  27         spinner = '<div class="spinner spinner-32px spinner-h-center"></div>';
  28         if ($container.is('table,tbody,thead,tfoot')) {
  29             // Hack to determine how many columns a new tr should have
  30             // in order to reach full width.
  31             colspan = $container.closest('table').
  32                 find('tr').eq(0).find('td,th').length;
  33             if (colspan == 0)
  34                 colspan = '*';
  35             spinner = ('<tr class="spinner"><td colspan="' + colspan + '">' +
  36                        spinner +
  37                        '</td></tr>');
  38         }
  39         $container.find(".spinner").detach();
  40         $container.append(spinner);
  41         $container.attr('data-infinite-serial', serial);
  42         $.ajax(src,
  43                {dataType: 'json',
  44                 type: 'GET',
  45                 data: ($container.data('infinite-content-params') || {}),
  46                 context: {container: $container, src: src, serial: serial}}).
  47             fail(function(jqxhr, status, error) {
  48                 var $faildiv;
  49                 var $container = this.container;
  50                 if ($container.attr('data-infinite-serial') != this.serial) {
  51                     // A newer request is already in progress.
  52                     return;
  53                 }
  54                 if (jqxhr.readyState == 0 || jqxhr.status == 0) {
  55                     message = "Cancelled."
  56                 } else if (jqxhr.responseJSON && jqxhr.responseJSON.errors) {
  57                     message = jqxhr.responseJSON.errors.join("; ");
  58                 } else {
  59                     message = "Request failed.";
  60                 }
  61                 // TODO: report the message to the user.
  62                 console.log(message);
  63                 $faildiv = $('<div />').
  64                     attr('data-infinite-content-href', this.src).
  65                     addClass('infinite-retry').
  66                     append('<span class="fa fa-warning" /> Oops, request failed. <button class="btn btn-xs btn-primary">Retry</button>');
  67                 $container.find('div.spinner').replaceWith($faildiv);
  68             }).
  69             done(function(data, status, jqxhr) {
  70                 if ($container.attr('data-infinite-serial') != this.serial) {
  71                     // A newer request is already in progress.
  72                     return;
  73                 }
  74                 $container.find(".spinner").detach();
  75                 $container.append(data.content);
  76                 $container.attr('data-infinite-content-href', data.next_page_href);
  77             });
  78      }
  79 }
  80
  81 $(document).
  82     on('click', 'div.infinite-retry button', function() {
  83         var $retry_div = $(this).closest('.infinite-retry');
  84         var $scroller = $(this).closest('.infinite-scroller')
  85         $scroller.attr('data-infinite-content-href',
  86                        $retry_div.attr('data-infinite-content-href'));
  87         $retry_div.replaceWith('<div class="spinner spinner-32px spinner-h-center" />');
  88         $scroller.trigger('scroll');
  89     }).
  90     on('refresh-content', '[data-infinite-scroller]', function() {
  91         // Clear all rows, reset source href to initial state, and
  92         // (if the container is visible) start loading content.
  93         var first_page_href = $(this).attr('data-infinite-content-href0');
  94         if (!first_page_href)
  95             first_page_href = $(this).attr('data-infinite-content-href');
  96         $(this).
  97             html('').
  98             attr('data-infinite-content-href', first_page_href);
  99         $('.infinite-scroller').
 100             trigger('scroll');
 101     }).
 102     on('ready ajax:complete', function() {
 103         $('[data-infinite-scroller]').each(function() {
 104             if ($(this).hasClass('infinite-scroller-ready'))
 105                 return;
 106             $(this).addClass('infinite-scroller-ready');
 107
 108             var $scroller = $($(this).attr('data-infinite-scroller'));
 109             if (!$scroller.hasClass('smart-scroll') &&
 110                 'scroll' != $scroller.css('overflow-y'))
 111                 $scroller = $(window);
 112             $scroller.
 113                 addClass('infinite-scroller').
 114                 on('scroll resize', { container: this }, maybe_load_more_content).
 115                 trigger('scroll');
 116         });
 117     });