Rewriting a JSON string - grouping keys by value into a new two level deep array?

Question

Just building on top of my previous question here:

Rewriting a JSON string - grouping keys by value into a new array?

I am wondering how do I traverse the array given and resort it so that the output comes out something like this:

[{
"Name": "Title 1",
"Date": "2012-12-05",
"rows": [
    {
        "Subtitle": "Subtitle 1",
        "Count1": 566,
        "Count2": 105
    },
    {
        "Subtitle": "Subtitle 2",
        "Count1": 76,
        "Count2": 15
    }
    ]
}, 
{
"Name": "Title 2",
"Date": "2012-12-06",
"rows": [
    {
        "Count1": 66,
        "Count2": 5
    }...

where the original json array is grouped by "Name" column, and then sorted into multi-level structure like this (parent/multiple child json structure for properly building menu in our application)?

The original json data looks like this:

[{
"Name": "Title 1",
"Subtitle": "Subtitle 1",
"Count1": 556,
"Count2": 5,
"Date": "2012-12-05"
}, {
"Name": "Title 1",
"Subtitle": "Subtitle 2",
"Count1": 10,
"Count2": 100,
"Date": "2012-12-05"
}, {
"Name": "Title 3",
"Subtitle": "Subtitle 3",
"Count1": 798,
"Count2": 11,
"Date": "2012-12-04"
}...

and obviously I am looking for a solution in PHP, as I will read in the json data, process it and spit it out reformatted.

What does the original data look like? The data in the earlier question doesn't have subtitles. And more to the point: what have you tried? You seem to be using SO as a "write this for me" service, it's supposed to be "help me fix my code". — Barmar
– Barmar, Commented Dec 23, 2012 at 7:58
I've updated the original question with the sample json data for this... and what have I tried? Nothing yet as I can't even fathom in my head how I'd approach this to begin with... hence the question. If I tried something and it was close but didn't work exactly the way I needed it, I would've posted that as well. — Crazy Serb
– Crazy Serb, Commented Dec 23, 2012 at 12:05

benedict_w · Accepted Answer · 2012-12-30 22:11:30Z

2

Assuming associative arrays and sorting output by name:

$output = array();

for ($data as $row) {

    if (!isset($output[$row['Name']])) {
        $output[$row['Name']] = array(
            'Name' => $row['Name'],
            'Date' => $row['Date'],
            'rows' => array()
        );
    }

    $output[$row['Name']]['rows'][] = array(
        'Subtitle' => $row['Subtitle'],
        'Count 1'  => $row['Count 1'],
        'Count 2'  => $row['Count 2'] 
    );
}

edited Dec 30, 2012 at 22:11

answered Dec 30, 2012 at 21:57

benedict_w

3,6282 gold badges35 silver badges51 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Crazy Serb Over a year ago

I was pretty close with what I had on my end... I just ended up using array_push at the very end instead to add a new child item, but was missing a piece of the puzzle from the code above. Thanks!

Barmar · Accepted Answer · 2012-12-23 12:25:55Z

1

hash = {};
result = [];
for (var i = 0; i < data.length; i++) {
    var name = data[i].Name;
    if (!hash.hasOwnProperty(name)) {
        var newitem = { Name: name,
                        Date: data[i].Date,
                        rows: []
                      };
        result.push(newitem);
        hash[name] = newitem;
    }
    hash[name].rows.push({ Subtitle: data[i].Subtitle,
                           Count1: data[i].Count1,
                           Count2: data[i].Count2
                         });
}

answered Dec 23, 2012 at 12:25

Barmar

789k57 gold badges555 silver badges669 bronze badges

2 Comments

Crazy Serb Over a year ago

I'd need this in PHP, as doing it in the front-end, given the data set I'll be working with, will cause way too much overhead in the browser... but thanks for that approach/solution.

Barmar Over a year ago

Sorry, missed that. But the algorithm is the same, just change the syntax.

Collectives™ on Stack Overflow

Rewriting a JSON string - grouping keys by value into a new two level deep array?

2 Answers 2

1 Comment

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related