Convert flat JSON file to hierarchical json data like flare.json [d3 example file]

Question

After a troublesome fight i almost figured how to convert a flat json file to a Hierarchical one. I didn\'t write the function by my own. I copied it from the below post.

Answer 1

Updated to use a recursive method

This should work for n levels rather than just 2 or 3. You just need to specify which properties define which levels.

var data = [
    { "dep": "First Top", "name": "First child", "model": "value1", "size": "320" },
    { "dep": "First Top", "name": "First child", "model": "value2", "size": "320" },
    { "dep": "First Top", "name": "SECOND CHILD", "model": "value1", "size": "320" },
    { "dep": "Second Top", "name": "First Child", "model": "value1", "size": "320" }
];

var newData = { name :"root", children : [] },
    levels = ["dep","name"];

// For each data row, loop through the expected levels traversing the output tree
data.forEach(function(d){
    // Keep this as a reference to the current level
    var depthCursor = newData.children;
    // Go down one level at a time
    levels.forEach(function( property, depth ){

        // Look to see if a branch has already been created
        var index;
        depthCursor.forEach(function(child,i){
            if ( d[property] == child.name ) index = i;
        });
        // Add a branch if it isn't there
        if ( isNaN(index) ) {
            depthCursor.push({ name : d[property], children : []});
            index = depthCursor.length - 1;
        }
        // Now reference the new child array as we go deeper into the tree
        depthCursor = depthCursor[index].children;
        // This is a leaf, so add the last element to the specified branch
        if ( depth === levels.length - 1 ) depthCursor.push({ name : d.model, size : d.size });
    });
});