Creating a JSON Tree from a string hierarchy

Question

Given these 4 variables,

var el1 = {name:'ronaldo', team: 'europe/spain/realmadrid'}
var el2 = {name:'messi', team: 'europe/spain/barcelona'}
var el3 = {name:'gerald', team: 'europe/england/liverpool'}
var el4 = {name:'unknown english', team: 'europe/england'}

I need to produce this JSON tree hierarchy,

{
    "text":"europe",
    "leaf":false,
    "children":[
        {
            "text":"spain",
            "leaf":false,
            "children":[
                {
                    "text":"realmadrid",
                    "leaf":false,
                    "children":[
                        {
                            "text":"ronaldo",
                            "leaf":true
                        }
                    ]
                },
                {
                    "text":"barcelona",
                    "leaf":false,
                    "children":[
                        {
                            "text":"messi",
                            "leaf":true
                        }
                    ]
                }
            ]
        },
        {
            "text":"england",
            "leaf":false,
            "children":[
                {
                    "text":"unknown english",
                    "leaf":true
                },
                {
                    "text":"liverpool",
                    "leaf":false,
                    "children":[
                        {
                            "text":"gerald",
                            "leaf":true
                        }
                    ]
                }
            ]
        }
    ]
}

Answer 1

It'd be waaay easier if somehow el1-el4 were combined into a single object, like

var data = []
data[0] = {name:'ronaldo', team: 'europe/spain/realmadrid'}
data[1] = {name:'messi', team: 'europe/spain/barcelona'}
data[2] = {name:'gerald', team: 'europe/england/liverpool'}
data[3] = {name:'unknown english', team: 'europe/england'}

That way you can at least loop through them quickly when processing.

It'd also be useful to know why you need to have this stored as a JSON Tree. I mean, not all the nodes are the same kind of thing, right? The first level is continent, then country, then team name, and the leaves are individual soccer players. That's a fairly confusing data structure and I'm not sure how it would be useful. Either way, it may be more useful to translate it into a fielded structure first and then generate the tree.

Edit: Okay, so I thought about it a bit more and I think maybe something like this may do it.

var data = [];
data[0] = {name:'ronaldo', team: 'europe/spain/realmadrid'};
data[1] = {name:'messi', team: 'europe/spain/barcelona'};
data[2] = {name:'gerald', team: 'europe/england/liverpool'};
data[3] = {name:'unknown english', team: 'europe/england'};

var tree = {};
function fillTree(name,steps) {
   current = null;
   for (var y = 0; y < steps.length; y++) {
      if (y==0) {
         if (!tree.children||typeof tree.children == 'undefined'){
            tree = { text: steps[y], leaf: false, children: [] };
         }
         current = tree.children;
      } else {
         current.push({ text: steps[y], leaf: false, children: [] })
         current = current[current.length - 1].children;
      }
   }
   current.push({ text: name, leaf: true })
}

for (x=0; x < data.length; x++) {
  steps =data[x].team.split('/');
  fillTree(data[x].name,steps)
}

This creates a JavaScript object. I leave it to you to convert this to JSON.

Update:

Yeah, I see that the old script would have always put a record in at the second level even if it already existed. This is the new improved FillTree function:

var tree = {};
function fillTree(name,steps) {
   var current = null,
   existing = null,
   i = 0;
   for (var y = 0; y < steps.length; y++) {
      if (y==0) {
         if (!tree.children||typeof tree.children == 'undefined'){
            tree = { text: steps[y], leaf: false, children: [] };
         }
         current = tree.children;
      } else {
         existing = null;
         for (i=0; i < current.length; i++) {
            if (current[i].text === steps[y]) {
               existing = current[i];
               break;
            }
         }
         if (existing) {
            current = existing.children;
         } else {
            current.push({ text: steps[y], leaf: false, children: [] });
            current = current[current.length - 1].children;
         }
      }
   }
   current.push({ text: name, leaf: true })
}

The easiest way to convert this object into JSON, apparently, is to use JSON.stringify(tree) although apparently this is not uniformly supported (see the JavaScript JSON Page).