//Takes an array of JSON and groups objects in an array based on the head key.

//Data is collected in the values key.

function convertJSONArray2HeaderArray(arr,head,values){

var headerArray = arr.map( function(item) {return item[this];},String(head));

headerArray = headerArray.filter( function( item, index, inputArray ) {

return inputArray.indexOf(item) == index;

});

var headerArray = headerArray.map( function(item) {

var newObject = new Object();

newObject[String(head)]=item;

newObject[String(values)]=[];

return newObject;

});

for(var i =0;i<arr.length;i++){

var keyname = arr[i][String(head)];

for(var j=0;j<headerArray.length;j++){

if(headerArray[j][String(head)]==keyname){

break;

}

}

headerArray[j][String(values)].push(arr[i]);

}

return headerArray;

}

//Reverts an array with header to a simple JSON array. Data is held in the values key.

function convertHeaderArray2JSONArray(headerArray,values){

var JSONArray = [];

headerArray.forEach(function(item){

JSONArray = JSONArray.concat(item[String(values)]);

});

return JSONArray;

}