Mixin: SC.TreeItemContent
A tree item is a model object that acts as a node in a tree-like data structure such as a hierarchy of folders or outline of items. This mixin can be applied to tree item model objects to customize the way the tree information is extracted from the object.
Basic Implementation
If you add this mixin, you must implement the treeItemChildren property so
that it returns the current array of child tree items for the receiver. If
you do not implement this property the tree item will not function.
Optimizing Branches
The most common use of this mixin is to override the treeItemBranchIndexes
property to return an index set of child items that are themselves branches
in the tree. Normally the TreeController will need to walk every item in
your list to determine these branch items. However by implementing this
method yourself, you can provide a result faster.
If none of your child items are branches, override this property to return null or an empty index set.
Defined in: tree_item_content.js
- Since:
- SproutCore 1.0
Field Summary
- SC.TreeItemContent.isTreeItemContent
- SC.TreeItemContent.treeItemChildren
- SC.TreeItemContent.treeItemIsExpanded
- SC.TreeItemContent.treeItemIsGrouped
Class Methods
- treeItemBranchIndexes(parent, index)
- treeItemCollapse(parent, idx)
- treeItemDisclosureState(parent, idx)
- treeItemExpand(parent, idx)
Field Detail
SC.TreeItemContent.isTreeItemContent Boolean- Default value:
- YES
Property returns the children for this tree item. The default simply returns null. If you implement this mixin, you MUST implement this property to return the actual tree item children for the item.
- Default value:
- null
The default property used to determine if the tree item is expanded. You
can implement you model object to update this property or you can override
treeItemDisclosureState() to compute the disclosure state however you
want.
- Default value:
- YES
Indicates whether the tree item should be rendered as a group or not.
This property is only useful on the root item in your tree. Setting it to
YES on any other item will be ignored.
- Default value:
- NO
Class Method Detail
Returns an index set containing the child indexes of the item that are themselves branches. This will only be called on tree items with a branch disclosure state.
If the passed parent and index are both null, then the receiver is the root node in the tree.
The default implementation iterates over the item's children to get the disclosure state of each one. Child items with a branch disclosure state will have their index added to the return index set.
You may want to override this method to provide a more efficient implementation if you are working with large data sets and can infer which children are branches without iterating over each one.
If you know for sure that all of the child items for this item are leaf nodes and not branches, simply override this method to return null.
- Parameters:
- parent Object
- the parent item containing this item
- index Number
- the index of the item in the parent
- Returns:
- SC.IndexSet
- branch indexes
Collapse the tree item. The default implementation will change the
treeItemIsExpanded property, but you can override this method to handle
collapsing anyway you like.
- Parameters:
- parent Object
- the parent item containing this item
- idx Number
- the index of the item in the parent
- Returns:
- void
Returns the disclosure state for the tree item, which appears at the
index of the parent's treeItemChildren array. The response must be one of
SC.BRANCH_OPEN, SC.BRANCH_CLOSED or SC.LEAF_NODE.
If the parent parameter is null, then this item is part of the root children array.
This method will only be called for tree items that have children. Tree items with no children are assumed to be leaf nodes.
The default implementation uses the treeItemIsExpanded property to
determine if the item should be open or closed.
- Parameters:
- parent Object
- the parent item containing this item
- idx Number
- the index of the item in the parent
- Returns:
- Number
- branch state
Expand the tree item. The default implementation will change the
treeItemIsExpanded property, but you can override this method to handle
collapsing anyway you like.
- Parameters:
- parent Object
- the parent item containing this item
- idx Number
- the index of the item in the parent
- Returns:
- void