dust js looping through objects in json

Question

I am having trouble in using dust.js to loop through a json, here is my json

{
   "Undergraduate":{
      "metaid":"0770",
      "Offcampus":{
         "FeesItems":{
            "tuition":{
               "label":"Tuition Fees",
               "value":"5,870"
            },
            "comprehensive":{
               "label":"Comprehensive Fees",
               "value":"2,141"
            },
            "studentActivity":{
               "label":"Student Activity Fees",
               "value":"190"
            },
            "academicExcellence":{
               "label":"Academic Excellence Fee",
               "value":"225"
            },
            "room":{
               "label":"Room",
               "value":"0"
            },
            "board":{
               "label":"Board",
               "value":"0"
            },
            "livingAllowance":{
               "label":"Living Allowance",
               "value":"9,738"
            }
         }
      } 
   }
}

I would like to loop through the items inside FeesItems object..

{#Undergradaute.Offcampus.FeesItems}
  {label}, {value}{~n}   <!-- What should be given in this line? -->
{/Undergradaute.Offcampus.FeesItems}

Answer 1

This will loop through the items in FeesItems rendering label and value from JSON as long as FeesItems is an array FeesItems= []

http://akdubya.github.io/dustjs/#guide

{
   "Undergraduate":{
      "metaid":"0770",
      "Offcampus":{
         "FeesItems":[{
               "label":"Tuition Fees",
               "value":"5,870"
            },
            {
               "label":"Comprehensive Fees",
               "value":"2,141"
            },
            ...
]
         }
      } 
   }
}

Here is a sample of the Dust Guide:

{#friends}
  {name}, {age}{~n}
{/friends}

{
  friends: [
    { name: "Moe", age: 37 },
    { name: "Larry", age: 39 },
    { name: "Curly", age: 35 }
  ]
}

Update 1:

Since you desire not to change the original JSON you will need to generate a new Object from your original JSON Something like

var newModel =  Object.keys(obj.Undergraduate.Offcampus.FeesItems).map(function(prop){ return obj.Undergraduate.Offcampus.FeesItems[prop] });

Please note that javascript will keep the reference to objects, if try something something like:

originalObj.Undergraduate.Offcampus.FeesItems.board.label = "Costa Rica"
console.log(newModel[5].label);

Answer 2

You can iterate over an object using a helper.

For example, you could define a helper like this one:

dust.helpers.iter = function(chunk, context, bodies, params) {
  var obj = dust.helpers.tap(params.obj, chunk, context);

  var iterable = [];

  for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
      var value = obj[key];

      iterable.push({
        '$key': key,
        '$value': value,
        '$type': typeof value
      });
    }
  }

  return chunk.section(iterable, context, bodies);
};

Then, in your template, you would loop through like this:

{@iter obj=Undergradaute.Offcampus.FeesItems}
  {$value.label}, {$value.value}{~n}
{/iter}