Convert coldfusion json to struct

Question

I have a JSON variable output from a jQuery application as so:

[{"id":1},
{"id":197,"children":[{"id":198},{"id":199},{"id":200}]},
{"id":2,"children":[{"id":3},{"id":4},{"id":143},{"id":6},{"id":5},{"id":7},{"id":8},{"id":9},{"id":10},{"id":11},{"id":12}]},
{"id":15,"children":[{"id":17},{"id":190},{"id":191},{"id":131},{"id":16},{"id":142},{"id":124}]},
{"id":149,"children":[{"id":150},{"id":160},{"id":161},{"id":184}]},
{"id":20,"children":[{"id":132},{"id":127},{"id":152},{"id":107},{"id":108},{"id":109},{"id":110},{"id":125},{"id":128},{"id":130},{"id":129},{"id":112}]},
{"id":162,"children":[{"id":163},{"id":164},{"id":165},{"id":166},{"id":186},{"id":187}]},
{"id":167,"children":[{"id":173},{"id":168},{"id":170},{"id":169},{"id":192},{"id":194}]},
{"id":174,"children":[{"id":176},{"id":175},{"id":188}]},
{"id":153,"children":[{"id":178},{"id":179},{"id":195},{"id":154},{"id":157}]},
{"id":180,"children":[{"id":181},{"id":182},{"id":183},{"id":189}]},
{"id":122},
{"id":21},
{"id":13},
{"id":92},
{"id":22},
{"id":113},
{"id":114}]

I need to convert this variable to a struct and then loop the struct by the first id parameter to find the children for each id (if there is one). I have tried to convert it as a structure like so but I am getting an error:

<cfset jsonarray = deserializeJson(output)>
<cfloop collection="#jsonarray#" index="id">
<cfdump var="#jsonarray[id]#">
</cfloop>

It does not recognize the variable as a structure:

Invalid collection [{id={1}}, {children={[{id={198}}, {id={199}}, {id={200}}]},id={197}}, {children={[{id={3}}, {id={143}}, {id={4}}, {id={6}}, {id={5}}, {id={7}}, {id={8}}, {id={9}}, {id={10}}, {id={11}}, {id={12}}]},id={2}}, {children={[{id={17}}, {id={190}}, {id={191}}, {id={131}}, {id={16}}, {id={142}}, {id={124}}]},id={15}}, {children={[{id={150}}, {id={160}}, {id={161}}, {id={184}}]},id={149}}, {children={[{id={132}}, {id={127}}, {id={152}}, {id={107}}, {id={108}}, {id={109}}, {id={110}}, {id={125}}, {id={128}}, {id={130}}, {id={129}}, {id={112}}]},id={20}}, {children={[{id={163}}, {id={164}}, {id={165}}, {id={166}}, {id={186}}, {id={187}}]},id={162}}, {children={[{id={173}}, {id={168}}, {id={170}}, {id={169}}, {id={192}}, {id={194}}]},id={167}}, {children={[{id={176}}, {id={175}}, {id={188}}]},id={174}}, {children={[{id={178}}, {id={179}}, {id={195}}, {id={154}}, {id={157}}]},id={153}}, {children={[{id={181}}, {id={182}}, {id={183}}, {id={189}}]},id={180}}, {id={122}}, {id={21}}, {id={13}}, {id={92}}, {id={22}}, {id={113.... Must be a valid structure or COM object. 

Answer 1

In JSON, the [] denotes an array and {} a structure (or object). So your input is actually an array of structures. You need to use an array loop, not a collection loop:

<cfset arrayOfStructs = deserializeJson(output)>
<cfloop array="#arrayOfStructs#" index="parent">
      <cfset parentID = parent.id />
      ... 
</cfloop>

children is also an array of structures. Inside the outer loop, check for the existence of that key. If found, loop through the child array and do something with each of the id's:

  <cfif structKeyExists(parent, "children")>
      <cfloop array="#parent.children#" index="child">
          ...
      </cfloop>
  </cfif>

Answer 2

A tidy cfscript version. :)

<cfscript>
    structObj = deserializeJson(jsonString);

    for(i = 1; i LTE ArrayLen(structObj); i++){

        WriteOutput("parent id : " & structObj[i].id & "<br>"); 
        if(StructKeyExists(structObj[i], "children")){
            for(j = 1; j LTE ArrayLen(structObj[i].children); j++){
                WriteOutput("    -children id : " & structObj[i].children[j].id & "<br>");
            }
        }
    }
</cfscript>