Nesting storing and sorting in struct in angular - angularjs

Question

Ok, so I have a JSON file with lots of information that can be sorted many ways. The actual JSON is too large, but for a relevant example:
$myData =
{
"id":1,
"author_id":[17],
"date":"10/1/1996",
"title":"Article1"
},
{
"id":2,
"author_id":[16,17],
"date":"9/1/1996",
"title":"Article2"
},
{
"id":3,
"author_id":[16],
"date":"6/1/1996",
"title":"Article3"
};
I want to be able to sort this into a struct with the basic structure like:
$myDataByAuthor =
{"17" =
{
"id":1,
"date":"10/1/1996",
"title":"Article1"
},
{
"id":2,
"date":"9/1/1996",
"title":"Article2"
}
},
{"16" =
{
"id":3,
"date":"6/1/1996",
"title":"Article3"
};
{
"id":2,
"date":"9/1/1996",
"title":"Article2"
}
};
I know the syntax there is bad, but I'm not really sure how to lay this out which is why I'm asking.
The reason I want to do this is because I want to turn around and, using ng-repeat in my code be able to output something to effect of:
Author with id 16
6/1/1996 - Article3
9/1/1996 - Article2
Author with id 17
9/1/1996 - Article2
10/1/1996 - Article1
I'm just not seeing how to get this done.
Thanks!

Answer 1

You can certainly restructure it that way, and here is a fiddle and code of the function that would restructure it that way for you.
var table = {}
myData.forEach(function(element){
element.author_id.forEach(function(id){
table[id] = table[id] || []
table[id].push(element)
})
})
https://jsfiddle.net/q40yhhko/

Answer 2

Considering your data is:
$myData = [{ "id":1, "author_id":[17], "date":"10/1/1996", "title":"Article1"},
{"id":2, "author_id":[16,17], "date":"9/1/1996", "title":"Article2"},
{"id":3, "author_id":[16], "date":"6/1/1996", "title":"Article3" }];
To form the required JSON use below code
$scope.requiredJSON = {}; //FORMATED JSON DATA
angular.foreach($myData, function(value, index){
angular.foreach(value.author_id, function(innerVal, innerIndex){
$scope.requiredJSON[innerVal] = $scope.requiredJSON[innerVal] || [];
$scope.requiredJSON[innerVal].push({id: value.id, date: value.date, title: value.title});
})
});
Following is the output:
{17: [{"id":1, "date":"10/1/1996", "title":"Article1" },
{"id":2, "date":"9/1/1996", "title":"Article2" }],
16: [{"id":2, "date":"9/1/1996", "title":"Article2" }]};
https://jsfiddle.net/AmitParrikar/uzv2p72b/2/