jquery.autopager-1.0.0.js

/*
 * jQuery.autopager v1.0.0
 *
 * Copyright (c) lagos
 * Dual licensed under the MIT and GPL licenses.
 */
(function($) {
  var window = this, options = {},
    content, currentUrl, nextUrl,
    active = false,
    defaults = {
      autoLoad: true,
      page: 1,
      content: '.content',
      link: 'a[rel=next]',
      insertBefore: null,
      appendTo: null,
      start: function() {},
      load: function() {},
      disabled: false
    };

  $.autopager = function(_options) {
    var autopager = this.autopager;

    if (typeof _options === 'string' && $.isFunction(autopager[_options])) {
      var args = Array.prototype.slice.call(arguments, 1),
        value = autopager[_options].apply(autopager, args);

      return value === autopager || value === undefined ? this : value;
    }

    _options = $.extend({}, defaults, _options);
    autopager.option(_options);

    content = $(_options.content).filter(':last');
    if (content.length) {
      if (!_options.insertBefore && !_options.appendTo) {
        var insertBefore = content.next();
        if (insertBefore.length) {
          set('insertBefore', insertBefore);
        } else {
          set('appendTo', content.parent());
        }
      }
    }

    setUrl();

    return this;
  };

  $.extend($.autopager, {
    option: function(key, value) {
      var _options = key;

      if (typeof key === "string") {
        if (value === undefined) {
          return options[key];
        }
        _options = {};
        _options[key] = value;
      }

      $.each(_options, function(key, value) {
        set(key, value);
      });
      return this;
    },

    enable: function() {
      set('disabled', false);
      return this;
    },

    disable: function() {
      set('disabled', true);
      return this;
    },

    destroy: function() {
      this.autoLoad(false);
      options = {};
      content = currentUrl = nextUrl = undefined;
      return this;
    },

    autoLoad: function(value) {
      return this.option('autoLoad', value);
    },

    load: function() {
      setUrl();
      if (active || !nextUrl || options.disabled) {
        return;
      }

      active = true;
      options.start(currentHash(), nextHash());
      $.get(nextUrl, insertContent);
      return this;
    }

  });

  function set(key, value) {
    switch (key) {
      case 'autoLoad':
        if (value && !options.autoLoad) {
          $(window).scroll(loadOnScroll);
        } else if (!value && options.autoLoad) {
          $(window).unbind('scroll', loadOnScroll);
        }
        break;
      case 'insertBefore':
        if (value) {
          options.appendTo = null;
        }
        break
      case 'appendTo':
        if (value) {
          options.insertBefore = null;
        }
        break
    }
    options[key] = value;
  }

  function setUrl(context) {
    currentUrl = nextUrl || window.location.href;
    nextUrl = $(options.link, context).attr('href');
  }

  function loadOnScroll() {
    if (content.offset().top + content.height() < $(document).scrollTop() + $(window).height()) {
      $.autopager.load();
    }
  }

  function insertContent(res) {
    if (typeof res === 'object') {
      res = res.regions.search_api_ajax;
    }

    var _options = options,
      nextPage = $('<div/>').append(res.replace(/<script(.|\s)*?\/script>/g, "")),
      nextContent = nextPage.find(_options.content);
      nextPager = nextPage.find(_options.pager);

    set('page', _options.page + 1);
    setUrl(nextPage);
    if (nextContent.length) {
      if (_options.insertBefore) {
        nextContent.insertBefore(_options.insertBefore);
      } else {
        nextContent.appendTo(_options.appendTo);
      }
      $(_options.pager).replaceWith(nextPager);
      _options.load.call(nextContent.get(), currentHash(), nextHash());
      content = nextContent.filter(':last');
    }
    active = false;
  }

  function currentHash() {
    return {
      page: options.page,
      url: currentUrl
    };
  }

  function nextHash() {
    return {
      page: options.page + 1,
      url: nextUrl
    };
  }
})(jQuery);