/
itemtree.go
114 lines (86 loc) · 2.27 KB
/
itemtree.go
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// Copyright 2015 Andreas Koch. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package filesystem
import (
"github.com/andreaskoch/allmark/common/route"
"github.com/andreaskoch/allmark/common/tree"
"github.com/andreaskoch/allmark/dataaccess"
"fmt"
)
func newItemTree() *ItemTree {
return &ItemTree{
*tree.Empty(),
}
}
type ItemTree struct {
tree.Tree
}
func (itemTree *ItemTree) Root() dataaccess.Item {
rootNode := itemTree.Tree.Root()
if rootNode == nil {
return nil
}
return nodeToItem(rootNode)
}
func (itemTree *ItemTree) Insert(item dataaccess.Item) (bool, error) {
if item == nil {
return false, fmt.Errorf("Cannot insert item into tree. The supplied item cannot be null.")
}
// convert the route to a path
path := tree.RouteToPath(item.Route())
return itemTree.Tree.Insert(path, item)
}
func (itemTree *ItemTree) Delete(itemRoute route.Route) (bool, error) {
return itemTree.Tree.Delete(itemRoute.Components())
}
func (itemTree *ItemTree) GetItem(route route.Route) dataaccess.Item {
// locate the node
node := itemTree.getNode(route)
if node == nil {
return nil
}
// cast the value
return nodeToItem(node)
}
func (itemTree *ItemTree) GetChildItems(route route.Route) []dataaccess.Item {
childItems := make([]dataaccess.Item, 0)
node := itemTree.getNode(route)
if node == nil {
return childItems
}
for _, childNode := range node.Children() {
item := nodeToItem(childNode)
if item == nil {
continue
}
childItems = append(childItems, item)
}
return childItems
}
func (itemTree *ItemTree) getNode(route route.Route) *tree.Node {
// convert the route to a path
path := tree.RouteToPath(route)
// locate the node
node := itemTree.Tree.GetNode(path)
if node == nil {
return nil
}
return node
}
// Walk visits every node in the current tree. Starting with the root, every child of the root and then recurses down the children.
func (itemTree *ItemTree) Walk(expression func(item dataaccess.Item)) {
itemTree.Tree.Walk(func(node *tree.Node) {
item := nodeToItem(node)
if item == nil {
return
}
expression(item)
})
}
func nodeToItem(node *tree.Node) dataaccess.Item {
if node.Value() == nil {
return nil
}
return node.Value().(dataaccess.Item)
}