apostrophe/public/js/vendor/jquery.bottomless.js

Apostrophe is a user-friendly content management system. This core module of Apostrophe provides rich content editing and essential facilities to integrate Apostrophe into your Express project. Apostrophe also includes simple facilities for storing your r

// bottomless: a jQuery plugin that makes it easy to set or get the
// current value of a group of bottomless buttons.
//
// Copyright 2013 P'unk Avenue LLC
//
// Please see:
//
// https://github.com/punkave/jquery-bottomless
//
// For complete documentation.

(function( $ ){
  $.fn.bottomless = function(options) {
    var $el = this;
    var url = options.url;
    var now = options.now || false;
    var page = options.page || 1;
    var skipAndLimit = options.skipAndLimit;
    // Consulted only if skipAndLimit is true, otherwise we just send a page parameter
    var perPage = options.perPage || 20;
    var resetTimeout = null;
    if (now) {
      if (options.page === undefined) {
        // loadPage will increment this and load page one immediately
        page = 0;
      }
    }
    var criteria = options.criteria || {};
    var distance = options.distance || 350;
    var method = options.method || 'GET';
    var $spinner = $(options.spinner);
    var atEnd = false;
    var loading = false;

    // Infinite scroll
    var interval = setInterval(function() {
      // Don't try anything fancy when we're not in the DOM, avoids
      // heavy background activity after removal. Also see
      // the aposScrollDestroy event
      if ($el.parents('body').length) {
        if ((!atEnd) && (!loading)) {
          // Allow for an intentional gap between the content of the
          // infinitely scrolled element and the bottom of the page
          // (although it's foolish to expect anyone to see it...!)
          var footerHeight = $(document).height() - ($el.offset().top + $el.height());
          if (($(document).scrollTop() + $(window).height() + distance) >= $(document).height() - footerHeight)
          {
            loadPage();
          }
        }
      }
    }, 100);

    $el.on('aposScrollReset', function(e, data) {
      function resetWhenAvailable() {
        if (loading) {
          if (resetTimeout) {
            clearTimeout(resetTimeout);
          }
          resetTimeout = setTimeout(resetWhenAvailable, 500);
          return;
        }

        resetTimeout = null;
        if (data) {
          criteria = data;
        }
        reset();
      }
      resetWhenAvailable();
    });

    $el.on('aposScrollEnded', function(e) {
      end();
    });

    $el.on('aposScrollDestroy', function(e) {
      end();
      // Go away!
      clearInterval(interval);
    });

    function afterPageOne() {
      if (!options.reset) {
        $el.html('');
      } else {
        options.reset();
      }
    }

    function reset() {
      page = 0;
      atEnd = false;
      loadPage();
    }

    function loadPage() {
      if (loading) {
        return setTimeout(loadPage,500);
      }
      start();
      page++;
      // Copy the criteria and add the page
      var query = {};
      $.extend(true, query, criteria);
      if (skipAndLimit) {
        query.skip = (page - 1) * perPage;
        query.limit = perPage;
      } else {
        query.page = page;
      }
      $.ajax({
        url: url,
        type: method,
        data: query,
        dataType: options.dataType || 'html',
        success: function(data) {
          if (page === 1) {
            afterPageOne();
          }
          (options.success || function(data) {
            var $items = $.parseHTML(data);
            $el.append($items);
            $el.data('page', page);
          })(data);
          stop();
          $el.trigger('aposScrollLoaded');
        },
        error: function() {
          if (page === 1) {
            afterPageOne();
          }
          $el.data('loading', false);
          loading = false;
        },
        statusCode: {
          404: function() {
            $el.trigger('aposScrollEnded');
          }
        }
      });
    }

    function start() {
      $el.data('loading', true);
      loading = true;
      $el.trigger('aposScrollStarted');
      $spinner.show();
    }

    function stop() {
      $el.data('loading', false);
      loading = false;
      $el.trigger('aposScrollStopped');
      $spinner.hide();
    }

    function end() {
      if (loading) {
        stop();
      }
      atEnd = true;
      $spinner.hide();
    }

    if (now) {
      loadPage();
    }
  };
})( jQuery );