get-tree.sql

CREATE OR REPLACE FUNCTION get_tree(data json) RETURNS json AS $$

var root = [];

for(var i in data) {
  build_tree(data[i]['id'], data[i]['name'], data[i]['children']);
}

function build_tree(id, name, children) {
  var exists = getObject(root, id);
  if(exists) {
       exists['children'] = children;
  }
  else {
    root.push({'id': id, 'name': name, 'children': children});
  }
}


function getObject(theObject, id) {
    var result = null;
    if(theObject instanceof Array) {
    for(var i = 0; i < theObject.length; i++) {
        result = getObject(theObject[i], id);
        if (result) {
        break;
        }   
    }
    }
    else
    {
    for(var prop in theObject) {
        if(prop == 'id') {
        if(theObject[prop] === id) {
            return theObject;
        }
        }
        if(theObject[prop] instanceof Object || theObject[prop] instanceof Array) {
        result = getObject(theObject[prop], id);
        if (result) {
            break;
        }
        } 
    }
    }
    return result;
}

    return JSON.stringify(root);
$$ LANGUAGE plv8 IMMUTABLE STRICT;