The LinkrTree class, just like the LinkrObject class, will keep you from re-coding the same lines over and over again. Let's use the ccBoard extension as an example:

var LinkrCCB = LinkrTree.getInstance();

The getInstance method takes 4 arguments:

• Object options: same as in LinkrObject
• Initial tree items: the very first tree items
• Search settings: SQL queries
• Template methods: same as in LinkrObject

Object options example:

var LinkrCCB_options =
{
  title : 'ccBoard',
  objName : 'LinkrCCB'
};
 

Tree items example:

var LinkrCCB_tree = [];
 
// Items have name, description, URL,
// expandIcon, and collapseIcon values
var LinkrCCB_tree_item =
{
  id : 'first-item',
  name : 'First Item'
};
LinkrCCB_tree.include(LinkrCCB_tree_item);

For documentation on using include (on arrays), follow this link .

Search settings example:

var LinkrCCB_search = {
  sql : {
    category : '',
    forum : ''
  }
};
 
// Category SQL
LinkrCCB_search.sql.category =
  'SELECT id, forum_name AS name '+
  'FROM #__ccb_forums '+
  'WHERE published = 1 AND cat_id = [query]';
 
// Forum SQL
LinkrCCB_search.sql.forum =
  'SELECT id, post_subject AS name, forum_id '+
  'FROM #__ccb_topics '+
  'WHERE forum_id = [query]';

Note that there's only one query for every search type, unlike with the LinkrObject class.

Template methods example:

var LinkrCCB_tmpl =
{
  setupTree : function(array, level)
  {
    // Tree items
    var tree = {};
 
    // The current tree level will
    // determine the search type
    switch (level)
    {
      // For demonstration purposes.
      // If you go back to the Search
      // settings example, you'll notice
      // that there's no "topic" type.
      // That's because topics won't
      // have any children items.
      case 2:
        var type = 'topic';
        break;
 
      case 1:
        var type = 'forum';
        break;
 
      default:
        var type = 'category';
    }
 
    // "array" is a list of database objects
    // resulting from one of the queries in
    // LinkrCCB_search.sql (see Search settings example).
    array.each(function(item)
    {
      // Item title
      var title = item.name;
 
      // Item URL. NOTE: In the ccBoard
      // extension, there is no "category" view.
      var url = false;
      if (type != 'category')
      {
        // Use the custom "url" helper method
        url = this.tmpl.url(type, item);
      }
 
      // Children items. NOTE: topics
      // don't have children items.
      var children = false;
      if (type != 'topic') {
        children = [type, item.id];
      }
 
      // Add item
      tree[item.id] =
      {
        title : title,
        url : url,
        level : level,
        children : children
      }
    }, this);
 
    return tree;
  },
 
  // Helper method to get URL
  url : function(type, item)
  {
    // Base for all URLs
    var url = 'index.php?option=com_ccboard';
 
    switch (type)
    {
      case 'forum':
        url += '&view=topiclist&forum='+ item.id;
        break;
 
      case 'topic':
        url += '&view=postlist&forum='+ i.forum_id +
                 '&topic='+ i.id;
        break;
    }
 
    return url;
  }
};

The final statement to get the object instance will look like:

var LinkrCCB = LinkrTree.getInstance(
      LinkrCCB_options,
      LinkrCCB_tree,
      LinkrCCB_search,
      LinkrCCB_tmpl
); 
 

Get the working plugin from JoomlaCode .

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