TryCF Gist

trycf-gist.cfm

<cfscript>
  
  TestData = querynew("id,parentId,nodeText");
  queryAddRow(TestData,{id:1,nodeText:"File" });
  queryAddRow(TestData,{id:2,nodeText:"New",parentId:1});
  queryAddRow(TestData,{id:3,nodeText:"File",parentId:2});
  queryAddRow(TestData,{id:4,nodeText:"Folder",parentId:2});
  queryAddRow(TestData,{id:5,nodeText:"Edit"});
  queryAddRow(TestData,{id:6,nodeText:"Copy",parentId:5});
  queryAddRow(TestData,{id:7,nodeText:"Cut",parentId:5});
  queryAddRow(TestData,{id:8,nodeText:"Paste",parentId:5});
  queryAddRow(TestData,{id:9,nodeText:"Help"});
  queryAddRow(TestData,{id:10,nodeText:"About",parentId:9});
  
  
  /**
   * Convert a hierarchical dataset into a nested tree
   * structure
   */
  function toNestedSet(query data) {
    // reduce the query to an array of nodes
    return data.reduce(function (stacks, curRow, idx, data) {
    
        // use stacks to track the result and branch positions
        stacks = stacks ?: {
             result = []
            ,branch = []
            ,lastNode = javaCast("null","")
        };
        
        // this is the actual data node
        var newNode = {
            nodeText: curRow.nodeText
        };
        
        var branchSize = stacks.branch.len();
        
        // encountering a "top-level" record resets the branch
        // stack and pushes the new node onto the result stack
        if (curRow.parentId == "") {
            stacks.lastNode = newNode;
            stacks.branch = [];
            stacks.result.add(newNode);
        
        // the current node references a parent - scan the
        // branch stack for the parent (we're assuming the
        // dataset is sorted)
        } else if (branchSize) {
            // scan the branch stack for the correct parent
            while ( branchSize 
                &&  stacks.branch[branchSize].id != curRow.parentId
            ) {
                stacks.branch.deleteAt(branchSize--);
            }
            
            // mark the parent as the "current" node
            stacks.lastNode = stacks.branch[branchSize].node;
            
            // create the children array as needed
            if (!stacks.lastNode.keyExists("children")) 
                stacks.lastNode.children = [];
            
            // add the child node
            stacks.lastNode.children.add(newNode);
        }
        
        // always add the new node to the current branch
        stacks.branch.add({
             node: newNode
            ,id: curRow.id
        });
        
        // mark the last node operated on
        stacks.lastNode = newNode;
        
        // if this is the last iteration return the result
        return idx == data.recordcount ? stacks.result : stacks;
    });
  
  }
  
  
  writedump(toNestedSet(TestData, "parentId"));
  
</cfscript>