Creating An Exploded View Of Flat Hierarchal Data Using Coldfusion

Assume the data is in an associative array such as the following:

<cfscript>
flatTable = StructNew();

flatTable["1"] = "root";
flatTable["2"] = "1";
flatTable["3"] = "1";
flatTable["4"] = "1";
flatTable["5"] = "2";
flatTable["6"] = "5";
flatTable["7"] = "3";
flatTable["8"] = "3";
</cfscript>

The first thing to do is to translate each flatTable entry into a structure that contains members for tracking parent and children.

<cfscript>
_working = StructNew();

// Have to create a placeholder for the Root node
_working["root"] = StructNew();
_working["root"].children = ArrayNew(1);
   
for (key in arguments.flatTable) {
     _working["#key#"] = newNode(key,tree[key]);
}
</cfscript>

The newNode function is defined as:

<cffunction name="newNode" returntype="Struct" >
     <cfargument name="key" type="string" required="true" />
     <cfargument name="value" type="string" required="true" />
  
     <cfscript>
     var tempStruct = StructNew();
     tempStruct.label = arguments.key; // key
     tempStruct.parent = arguments.value; // value
     tempStruct.children = ArrayNew(1);      
     return tempStruct;
     </cfscript>
</cffunction>


Now we can sort the structure to ensure that we can walk the hierarchy:

<cfscript>
sortedStruct = StructSort(arguments.flatTable,'textnocase');
</cfscript>

Since we have an ordered strcture, we now can complete the job by iterating over the struct in reverse:

<cfscript>
for (i=ArrayLen(sortedStruct); i>0; i--) {
     key = sortedStruct[i];
     parent = arguments.flatTable["#sortedStruct[i]#"];
  
     _working["#parent#"].children[ArrayLen(_working["#parent#"].children)+1] = _working["#key#"];
      
}   
</cfscript>

This can be abstracted into a single function reference (along with the newNode function):

<cffunction name="explodedView" returntype="struct">
     <cfargument name="flatTable" type="struct" required="true" />
     <cfset var _working = StructNew() />
     <cfset var sortedStruct = StructNew() />
   
     <cfscript>
     // create the root level node
     _working["root"] = StructNew();
     _working["root"].children = ArrayNew(1);
   
     for (key in arguments.flatTable) {
          _working["#key#"] = newNode(key,arguments.flatTable[key]);
     }
   
     sortedStruct = StructSort(arguments.flatTable,'textnocase');

     for (i=ArrayLen(sortedStruct); i>0; i--) {
          key = sortedStruct[i];
          parent = arguments.flatTable["#sortedStruct[i]#"];
      
          _working["#parent#"].children[ArrayLen(_working["#parent#"].children)+1] = _working["#key#"];
          
     }   
    
     return _working["root"];
     </cfscript>  
</cffunction>