使用JavaScript对JSON对象进行排序

Question

Okay.

I have a JSON object where each item of the object is a top level object...there are no nested relationships. Some of the items are nested, but everything is top level.

The way a nested relationship is setup is by the ID value.

• Item a = item_a
• Item b related to a = item_a.item_b
• Item c = item_c
• Item d related to c = item_c.item_d
• Item e related to d = item_c.item_d.item_e

I've tried splitting on the . and looping over the total json object and sorting them. I've tried 4 or 5 different ways that I can think of and nothing is working properly.

What I am trying to end up with is a single object that looks like this.

Obj = [{
    item_a: {
        nestedItems: [{
            item_b: {}
        }]
    },
    item_c: {
        nestedItems: [{
            item_d: {
                nestedItems: {
                    item_e: {}
                }
            }
        }]
    }    
}];

I can not change the output so let's not ask that question. This is the problem I'm trying to solve. Can anyone help me understand the best way to sort this?

Here is my current state...but it's far from complete:

function getNestedAttributes(attrs) // attrs is the JSON object
{
    var nested = [];

    for ( var i=0; i<attrs.length; i++ )
    {
        var idLevels = splitId(attrs[i].id); // split on . return array

        if ( idLevels.length == 1 )
        {
            nested[idLevels[0]] = attrs[i];
            nested[idLevels[0]]['nestedAttributes'] = [];
        }

        if ( idLevels.length > 1 )
        {
            nested[idLevels[0]]['nestedAttributes'].push(attrs[i]);
        }

    }

    console.log(nested);

}

The above is working to a point. I'm making everything an array, which is fine, but it only works for objects that have one level nested. Some items have up to 4 levels nested.

There has to be a better way to loop through this in JS.

JSON:

attributes: [
{
    id: "item_a",
    name: "Item A Name",
    ...
},
{
    id: "item_a.item_b",
    name: "Item B Name",
    ...
},
{
    id: "item_a.item_c",
    name: "Item C Name",
    ...
},
{
    id: "item_d",
    name: "Item D Name",
    ...
},
{
    id: "item_d.item_e",
    name: "Item E Name",
    ...
},
{
    id: "item_d.item_e.item_f",
    name: "Item F Name",
    ...
}];

The above is a very basic example, but this is what the output looks like.

Ideally I'd end up with the following:

attributes: [
{
    id: "item_a",
    name: "Item A Name",
    nestedAttributes: [{
        id: "item_a.item_b"
        name: "Item B Name"
        ...
    },
    {
        id: "item_a.item_c"
        name: "Item C Name"
        ...
    }],
    ...
},
{
    id: "item_d",
    name: "Item D Name",
    nestedAttributes: [{
        id: "item_d.item_e"
        name: "Item E Name"
        nestedAttributes: [{
            id: "item_d.item_e.item_f",
            name: "Item F Name",
            ...
        }],
        ...
    }],
    ...
}];

Answer 1

Well, besides the obvious fact that this entire structure needs to be rethought and borders on schizophrenic, the answer is pretty straightforward.

Here's a jsfiddle that works . Essentially you just want to accumulate object, checking at each level, over the key elements.

function build(attr) {
    var target, key, out = {},
        i = -1,
        len = attr.length;
    while (++i < len) {
        key = attr[i].id.split('.');
        target = makeOrFind(out, key);
        extend(target, attr[i]);
    }
    return out;
}

function makeOrFind(target, keyParts) {
    var key, i = -1, len = keyParts.length;
    while(++i < len) {
       key = keyParts[i];
        if( i > 0 ) {
           if( !target.nestedItems ) { target.nestedItems = {}; }
           target = target.nestedItems;
        }
       if( !target[key] ) { target[key] = {}; }
       target = target[key];
    }
    return target;
}

function extend(target, vals) {
   // this is an overly simple implementation of extend
   // it only works if your objects are exactly one level deep
   // but extend is a solved problem and not really in the scope of the question
    for( var key in vals ) {
        if( vals.hasOwnProperty(key) ) {
            target[key] = vals[key];   
        }
    }        
}

var out = build(attr);
console.log(out);

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